# Menu 5 − Motor Control

Mode: RFC‑S

Parameter | 05.001 Output Frequency
--- | ---
Short description | Frequency applied to the motor
Mode | RFC‑S
Minimum | -2000.0 | Maximum | 2000.0
Default |  | Units | Hz
Type | 32 Bit Volatile | Update Rate | 4ms write
Display Format | Standard | Decimal Places | 1
Coding | RO, FI, ND, NC, PT

The output frequency is not controlled directly, but the Output Frequency (05.001) is a measurement of the frequency applied to the motor.

Parameter | 05.002 Output Voltage
--- | ---
Short description | r.m.s. line to line voltage at the a.c. terminals.
Mode | RFC‑S
Minimum | −VM_AC_VOLTAGE | Maximum | VM_AC_VOLTAGE
Default |  | Units | V
Type | 16 Bit Volatile | Update Rate | 4ms write
Display Format | Standard | Decimal Places | 0
Coding | RO, FI, VM, ND, NC, PT

Output Voltage (05.002) is the r.m.s. line to line voltage at the a.c. terminals of the converter.

Parameter | 05.003 Output Power
--- | ---
Short description | Power flowing from the drive to the motor.
Mode | RFC‑S
Minimum | −VM_POWER | Maximum | VM_POWER
Default |  | Units | kW
Type | 32 Bit Volatile | Update Rate | 4ms write
Display Format | Standard | Decimal Places | 3
Coding | RO, FI, VM, ND, NC, PT

Output Power (05.003) is the power flowing via the a.c. terminals of the drive. The power is derived as the dot product of the output voltage and current vectors, and so this is correct even if the motor parameters are incorrect and the motor model does not align the reference frame with the flux axis of a motor in RFC-A mode. A positive value of power indicates power flowing from the drive to motor.

Parameter | 05.005 D.c. Bus Voltage
--- | ---
Short description | Displays the voltage across the d.c. terminals of the converter
Mode | RFC‑S
Minimum | −VM_DC_VOLTAGE | Maximum | VM_DC_VOLTAGE
Default |  | Units | V
Type | 16 Bit Volatile | Update Rate | 4ms write
Display Format | Standard | Decimal Places | 0
Coding | RO, FI, VM, ND, NC, PT

D.c. Bus Voltage (05.005) is the measured voltage at the d.c. terminals of the converter.

Parameter | 05.007 Rated Current
--- | ---
Short description | Set to the rated current of the motor
Mode | RFC‑S
Minimum | −VM_RATED_CURRENT | Maximum | VM_RATED_CURRENT
Default | Default Current Rating | Units | A
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 3
Coding | RW, VM

Rated Current (05.007) is used as follows:

Function | Details
Motor thermal protection | Defines the motor rated current.
Motor pre-heat | Motor pre-heat is set up as a percentage of rated current.
Sensorless low speed mode | The current for low speed sensorless is set-up as a percentage of rated current.
Current limits | Current limits are set up as a percentage of rated torque producing current.

Parameter | 05.008 Rated Speed
--- | ---
Short description | Set to the rated speed of the motor
Mode | RFC‑S
Minimum | 0.00 | Maximum | 33000.00
Default | 3000.00 | Units | rpm
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 2
Coding | RW

Rated Speed (05.008) is used in conjunction with Number Of Motor Poles (05.011) to define the rated frequency and this is used as described in the table below.

Function | Details
Sensorless control thresholds | The thresholds for changes from low speed starting mode to high speed normal operation and vice versa.
Flux controller gain | Rated frequency is to define the gain of the flux controller.

The units for Rated Speed (05.008) are always rpm even if a linear motor is used and Linear Speed Select (01.055) = 1.

Parameter | 05.009 Rated Voltage
--- | ---
Short description | Set to the rated voltage of the motor
Mode | RFC‑S
Minimum | −VM_AC_VOLTAGE_SET | Maximum | VM_AC_VOLTAGE_SET
Default | See exceptions below | Units | V
Type | 16 Bit User Save | Update Rate | 4ms read
Display Format | Standard | Decimal Places | 0
Coding | RW, VM

Voltage | Region | Default Value
200V | All | 230
400V | 50Hz | 400
400V | 60Hz | 460

The maximum voltage applied to the motor is either Rated Voltage (05.009), or the maximum possible voltage that the drive can produce minus some headroom defined by Voltage Headroom (05.041), whichever is lowest. The drive will not actively impose this limit unless maximum voltage control is active. See Enable High Speed Mode (05.022) for the conditions where the motor voltage control is active. Rated Voltage (05.009) is used as described in the table below.

Function | Details
Maximum motor voltage | To limit the motor voltage to the rated level for the motor.

Parameter | 05.011 Number Of Motor Poles
--- | ---
Short description | Set to the number of poles of the motor
Mode | RFC‑S
Minimum | 0 | Maximum | 240
Default | 3 | Units | PolePairs
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, BU

* The units relate to the numeric value of the parameter and not the text string as shown on the keypad.

Value (pole pairs) | Text
0 | Automatic
1 | 2 poles
2 | 4 poles
3 | 6 poles
... | ...
240 | 480 poles

The numeric value in Number Of Motor Poles (05.011) should be set to the number of motor pole pairs (i.e. number of motor poles / 2). The text strings associated with Number Of Motor Poles (05.011) show the number of motor poles (i.e. the parameter value x 2). If a linear position feedback device is used Number Of Motor Poles (05.011) should be set to 1 (2 Poles).

If Number Of Motor Poles (05.011) = 0 (Automatic) the number of motor poles = 3 (6 Poles).

During an autotune when position feedback is being used, the drive will check to ensure that the combination of motor poles and position feedback resolution have been set up correctly, and will produce an Autotune 7 trip if this is not the case. The Autotune 7 trip will not occur if Number Of Motor Poles (05.011) ≥ 6 (i.e. 12 poles).

Parameter | 05.012 Auto-tune
--- | ---
Short description | Defines the auto-tune test to be performed
Mode | RFC‑S
Minimum | 0 | Maximum | 5
Default | 0 | Units |
Type | 8 Bit Volatile | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE, NC

Value | Text
0 | None
1 | Stationary
2 | Rotating
3 | Inertia 1
4 | Inertia 2
5 | Full Stationary

The following describes how an auto-tune test can be initiated and normal operation can be resumed after the test for RFC-S mode:

An auto-tune test cannot be initiated if the drive is tripped or the drive inverter is active, i.e. Drive Healthy (10.001) = 0 or Drive Active (10.002) = 1. The inverter can be made inactive by ensuring that the Final drive enable is inactive, or the Final drive run is inactive and Hold Zero Speed (06.008) = 0.

1. An auto-tune test is initiated by setting Auto-tune (05.012) to a non-zero value and making the Final drive enable and the Final drive run active.
2. All tests that move the motor will move the motor in the forward direction if Reverse Select (01.012) = 0 or the reverse direction if Reverse Select (01.012) = 1. If the test is a stationary test Brake Control: Enable (12.041) is set to zero during the test and is then restored to its initial value when the test is complete.
3. If the auto-tune sequence is completed successfully the Final drive enable is set to the inactive state and Auto-tune (05.012) is set to zero. The Final drive enable can only be set to the active state again by removing the enable and re-applying it. The enable can be removed by setting Drive Enable (06.015) = 0, or by setting bit 0 of the Control Word (06.042) to 0 provided Control Word Enable (06.043) = 1, or by making Hardware Enable (06.029) = 0.
4. If a trip occurs during the auto-tune sequence the drive will go into the trip state and Auto-tune (05.012) is set to zero. As in 4 above the enable must be removed and re-applied before the drive can be restarted after the trip has been reset. However, care should be taken because if the auto-tune was not completed the drive parameters that should have been measured and set up will still have their original values.
5. If the Final drive enable is made active, the Final drive run is inactive and Hold Zero Speed (06.008) = 1 the drive would normally be in the Stop state (i.e. the inverter is active, but the frequency or speed reference is 0).

The following describes the effects of the auto-tune test on the drive parameters for RFC-S mode:

1. All auto-tune tests rely on the motor being stationary when the test is initiated to give accurate results.
2. If Select Motor 2 Parameters (11.045) = 0 then the parameters associated with motor map 1 are updated as a result of the test, and if Select Motor 2 Parameters (11.045) = 1 the parameters associated with motor map 2 are updated.
3. When each stage of the test is completed, the results are written to the appropriate parameters and these parameters saved in the drive non-volatile memory. If Parameter Cloning (11.042) is set to 3 or 4 the parameters are also written to a non-volatile media card fitted in the drive.

The table below shows the parameters required for motor control indicating which should be set by the user and which can be measured with an auto-tune test.

Parameter | Required for | Measured in test
Rated Current (05.007) | Basic control | User set-up
Rated Speed (05.008) | Basic control | User set-up
Rated Voltage (05.009) | Basic control | User set-up
Number Of Motor Poles (05.011) | Basic control | User set-up
Stator Resistance (05.017) | Basic control | 1, 2, 5
Ld (05.024) | Basic control | 1, 2, 5
Maximum Deadtime Compensation (05.059) | Basic control | 1, 2, 5
Current At Maximum Deadtime Compensation (05.060) | Basic control | 1, 2, 5
Current Controller Kp Gain (04.013) | Basic control | 1, 2, 5
Current Controller Ki Gain (04.014) | Basic control | 1, 2, 5
Volts Per 1000rpm (05.033) | Basic control | User set-up
Inverted Saturation Characteristic (05.070) | Sensorless control using current injection mode | User set-up
Phase Offset At Defined Iq Current (05.077) | Sensorless control using current injection mode | User set-up
Low Speed Sensorless Mode Current (05.071) | Sensorless control using current injection mode | User set-up
No-load Lq (05.072) | Sensorless control and high performance current control | 1, 2, 5
Lq At The Defined Iq Current (05.078) | Sensorless control | User set-up
Lq At The Defined Id Current (05.084) | Sensorless control | User set-up
Motor And Load Inertia (03.018) | Speed controller set-up and torque feed-forwards | 3, 4
Inertia Times 1000 (04.033) | Speed controller set-up and torque feed-forwards | 3, 4
Torque Per Amp (05.032) | Speed controller set-up and torque feed-forwards | User set-up
Position Feedback Phase Angle (03.025) | Basic control with position feedback | 1, 2, 5
User Defined Rated Torque Angle (05.087) | Low-saliency motors where additional torque is produced from motor reluctance. High-saliency motors and synchronous reluctance motors. | User set-up or automatic calculation if this parameter is zero.
Maximum Torque Angle (05.090) | Synchronous reluctance motors | User set-up

Auto-tune (05.012) should be used to carry out basic auto-tuning of the motor using a stationary test (1), a rotating test (2) or a full stationary test (5). This can be followed by either of the inertia tests (3 or 4) to measure the motor and load inertia which can be used to automatically set up the speed controller (see Speed Controller Set-up Method (03.017)). When selecting the basic test one of the following methods is used to find the d-axis of the motor (which is used to give the position feedback phase angle if position feedback is being used), and then to allow the measurement of the stator resistance and the d and q-axis inductances.

Stationary Test (Minimal Movement Phasing Test Angle (05.016) = 0.000) | Stationary Test (Minimal Movement Phasing Test Angle (05.016) > 0.000) | Rotating Test | Full Stationary Test
Inductance measurement test using high frequency currents. The motor can be free to move or constrained. Even if the motor is free to move there is likely to be no movement. | Minimal movement test using low frequency torque to vibrate the motor. The motor can be free to move or constrained, but the correct test must be selected with Minimal Movement Phasing Test Mode (05.013). | Rotating test that moves the motor through two electrical poles (240o / (Number of motor poles / 2) for a rotary motor, or 2 pole lengths for a linear motor). The motor must be free to move. | Inductance measurement or minimal movement is selected automatically depending on the saliency of the motor and whether position feedback is enabled or not. The motor can be free to move or constrained and the test will automatically select the appropriate test. If the motor is free to move it is likely to move by less than 30o electrical.
Can be used whether position feedback is enabled or not (i.e. Sensorless Mode Active (03.078) equals any value). | Can only be used when position feedback is enabled, (i.e. Sensorless Mode Active (03.078) = 0). The drive automatically uses inductance measurement if position feedback is not enabled. | Can only be used when position feedback is enabled, (i.e. Sensorless Mode Active (03.078) = 0). The drive automatically uses inductance measurement if position feedback is not enabled. | Can be used whether position feedback is enabled or not (i.e. Sensorless Mode Active (03.078) equals any value).
If the motor saliency is too low (as defined by 1 below) and position feedback is enabled, then a trip is initiated and the test fails. If position feedback is not enabled the test completes but the measured values of Ld and Lq may be misaligned. As these values are similar this is unlikely to be a problem. | If the torque produced from the magnet flux is too low compared the that produced from saliency, then it is possible for this test to give a very inaccurate value for the position feedback phase angle. To avoid this this test should not be used with motors where the equation 2 below is true. | If the torque produced from the magnet flux is too low compared the that produced from saliency, then it is possible for this test to give a very inaccurate value for the position feedback phase angle. To avoid this this test should not be used with motors where the equation 2 below is true. | Because this test automatically uses an inductance test if the saliency of the motor is low as defined by 3 below or position feedback is not enabled, it should avoid inaccurate measurement of the position feedback phase angle with a minimal movement test.
Some motors have high cogging torque which when combined with low saliency can make the measured position feedback phase angle inaccurate and vary with the position of the motor. For most motors the result of this test gives the position feedback phase angle within +/-5o which gives a loss of less than 1% of torque. | With most motors this method gives the position feedback phase angle within +/-2o. | With most motors this method gives the position feedback phase angle within +/-2o. | The accuracy depends on whether the test selects inductance or minimal movement test.
No movement is required during the test and Minimal Movement Phasing Test Angle (05.016) should be left at its default value of zero. | The test increases the torque pulsations until the required movement is achieved. The movement required must be defined in Minimal Movement Phasing Test Angle (05.016). | The movement during the test is always two electrical poles, and so Minimal Movement Phasing Test Angle (05.016) has no effect. | Minimal Movement Phasing Test Angle (05.016) is set up automatically as defined by 4 below.
If this test is completed successfully user parameters are set up and saved so that an inductance test is carried out on enable if Phasing Test On Enable (05.014) is set to a non-zero value. | If this test is completed successfully user parameters are set up and saved so that a minimal movement test is carried out on enable if Phasing Test On Enable (05.014) is set to a non-zero value. | If this test is completed successfully user parameters are set up and saved so that an inductance test is carried out on enable if Phasing Test On Enable (05.014) is set to a non-zero value. | If this test is completed successfully user parameters are set up and saved so that the same test that was used during this test is carried out on enable if Phasing Test On Enable (05.014) is set to a non-zero value. This includes automatically setting up Minimal Movement Phasing Test Mode (05.013) and Minimal Movement Phasing Test Angle (05.016).
This test can be used with all position feedback devices except commutation only devices. If it is used with a position feedback device that has digital commutation signals (i.e. AB Servo), then the motor must move by two electrical revolutions after the test for the position feedback phase angle to be accurate. The required movement is given by 240o / (Number of motor poles / 2) for a rotary motor, or 2 pole lengths for a linear motor. | This test can be used with all position feedback devices except commutation only devices. If it is used with a position feedback device that has digital commutation signals (i.e. AB Servo), then the motor must move by two electrical revolutions after the test for the position feedback phase angle to be accurate. The required movement is given by 240o / (Number of motor poles / 2) for a rotary motor, or 2 pole lengths for a linear motor. | This test can be used with all position feedback devices and the position feedback phase angle is accurate by the end of the test. | This test can be used with all position feedback devices except commutation only devices. If it is used with a position feedback device that has digital commutation signals (i.e. AB Servo), then the motor must move by two electrical revolutions after the test for the position feedback phase angle to be accurate. The required movement is given by 240o / (Number of motor poles / 2) for a rotary motor, or 2 pole lengths for a linear motor.
This test does not carry out any checks on the position feedback. | This test does not carry out any checks on the position feedback. | The position feedback is checked during this test and the test is aborted and a trip initiated if an error is detected. | This test does not carry out any checks on the position feedback.

> (1) (No-load Lq (05.072) - Ld (05.024)) / Ld (05.024) < 0.2.

> (2) Volts Per 1000rpm (05.033) / (Number Of Motor Poles (05.011) x ((No-load Lq (05.072) - (Ld (05.024)) / 1000) x Rated Current (05.007)) < 200.

> (3) (No-load Lq (05.072) - Ld (05.024)) / Ld (05.024) < 0.3.

> (4) If the inductance test is used Minimal Movement Phasing Test Angle (05.016) is set to zero. If the minimal movement test is used Minimal Movement Phasing Test Angle (05.016) is set to an angle equivalent to at least 75 counts from the position feedback device if it is a rotary device that is connected to the P1 position feedback interface on the drive subject to the following ranges.

> - Free test: minimum of 1.000° and maximum of 5.000°
> - Constrained test: minimum of 0.001° and maximum of 0.500°

> If the position feedback device is linear or not connected to the P1 position feedback interface on the drive, the minimum value is used. The table below shows how the calculation is performed for each type of device.

> Position feedback type | Calculation of minimal movement phasing test angle
> AB, FD, FR, AB Servo, FD Servo, FR Servo | 27000 / (P1 Rotary Lines Per Revolution (03.034) x 4)
> SC, SC Hiperface, SC EnDat, SC SSI, SC Servo, SC SC, SC Servo, SC BiSS | 27000 / (P1 Rotary Lines Per Revolution (03.034) x 4096)
> Resolver | 1.646° (This will be limited to 0.500° for a constrained test)
> EnDat, SSI, BiSS, EnDat Alt, BiSS Alt | 27000 / 2(P1 Comms Bits (03.035) - P1 Rotary Turns Bits (03.033))

The inertia tests are selected by setting Auto-tune (05.012) to 3 or 4 as described below.

3: Inertia 1
This test measures the mechanical characteristic of the motor and load by rotating the motor at the speed defined by the present speed reference and injecting a series of speed test signals. This test should only be used provided all the basic control parameters (including Torque Per Amp (05.032)) have been set-up correctly and the speed controller parameters should be set to conservative levels, such as the default values, so that the motor is stable when it runs. The test may give inaccurate results if standard ramp is active, particularly with high inertia low loss loads. The test measures the motor and load inertia, which can be used in automatic set-up of the speed controller gains and in producing a torque feed-forward term. If Mechanical Load Test Level (05.021) is left at its default value of zero then the peak level of the injection signal will be 1% of the maximum speed reference subject to a maximum of 500rpm. If a different test level is required then Mechanical Load Test Level (05.021) should be set to a non-zero value to define the level as a percentage of the maximum speed reference, again subject to a maximum of 500rpm. The user defined speed reference which defines the speed of the motor should be set to a level higher than the test level, but not high enough for flux weakening to become active. In some cases, however it is possible to perform the test at zero speed provided the motor is free to move, but it may be necessary to increase the test signal from the default value. The test will give the correct results when there is a static load applied to the motor and in the presence of mechanical damping. This test should be used if possible, however for sensorless mode, or if the speed controller cannot be set up for stable operation an alternative test is provided (Auto-tune (05.012) = 4) where a series of torque levels are applied to accelerate and decelerate the motor to measure the inertia.

4: Inertia 2
Auto-tune test 3 should normally be used for mechanical load measurement, but under some circumstances this test may be used as an alternative. This test is likely to give incorrect results if standard ramp mode is active. A series of progressively larger torque levels are applied to the motor (20%, 40% ... 100% of rated torque) to accelerate the motor up to 3/4 x VM_SPEED_FREQ_REF (i.e. speed reference variable maximum) to determine the inertia from the acceleration/deceleration time. The test attempts to reach the required speed within 5s, but if this fails the next torque level is used. When 100% torque is used the test allows 60s for the required speed to be reached, but if this is unsuccessful an Autotune 1.002 trip is initiated. To reduce the time taken for the test it is possible to define the level of torque to be used for the test by setting Mechanical Load Test Level (05.021) to a non-zero value. When the test level is defined the test is only carried out at the defined test level and 60s is allowed for the motor to reach the required speed. It should be noted that if the maximum speed allows for flux weakening then it may not be possible to achieve the required torque level to accelerate the motor fast enough. If this is the case, the maximum speed reference should be reduced. It is not possible to use Inertia test 2 in sensorless mode if RFC Low Speed Mode (05.064) is set to one of the of the current modes.

The table below shows the trips that can occur during an auto-tune test:

Trip | Reason
Autotune Stopped | The final drive enable or the final drive run were removed before the test was completed.
Resistance.001 | The measured value of Stator Resistance (05.017) exceeded a value of (VFS / √2) / Full Scale Current Kc (11.061), where VFS is the full scale d.c. link voltage.
Resistance.002 | It has not been possible to measure the drive inverter characteristic to define Maximum Deadtime Compensation (05.059) and Current At Maximum Deadtime Compensation (05.060).
Autotune 1.001 | The position feedback did not change when position feedback is being used.
Autotune 1.002 | The motor did not reach the required speed.
Autotune 1.003 | The required commutation signal edge could not be found with commutation signal only position feedback.
Autotune 1.004 | The required angular movement did not occur during a minimal movement test.
Autotune 1.006 | The phasing offset angle is measured twice during a stationary auto-tune and the two values were not within 30degrees.
Autotune 1.007 | The motor was rotating when a minimal movement test was performed to find the phasing offset angle on enable.
Autotune 1.009 | During the final stage of the minimal movement phasing test with a constrained motor it was not possible to achieve the required movement.
Autotune 2.001 | Position feedback direction is incorrect when position feedback is being used.
Autotune 2.002 | A SINCOS encoder with comms is being used for position feedback and the comms position is rotating in the opposite direction to the sine wave based position.
Autotune 3.001 | The measured inertia exceeds the parameter range.
Autotune 3.003 | The mechanical load test has failed to identify the inertia.
Autotune 3.002 | A position feedback device with commutation signals is being used (i.e. AB Servo, FD Servo, FR Servo, SC Servo) and the commutation signals changed in the wrong direction.
Autotune 4 | A position feedback device with commutation signals is being used (i.e. AB Servo, FD Servo, FR Servo, SC Servo) and U signal did not change.
Autotune 5 | A position feedback device with commutation signals is being used (i.e. AB Servo, FD Servo, FR Servo, SC Servo) and V signal did not change.
Autotune 6 | A position feedback device with commutation signals is being used (i.e. AB Servo, FD Servo, FR Servo, SC Servo) and W signal did not change.
Autotune 7 | The motor poles or the position feedback resolution have been set up incorrectly where position feedback is being used. The trip will not occur if Number Of Motor Poles (05.011) ≥ 6 (i.e. 12 poles).
Inductance.003 | The difference between the d and q axis inductance is not large enough to correctly determine the location of the motor flux. If position feedback is being used the measured value for Position Feedback Phase Angle (03.025) may not be reliable. Also the measured values of Ld (05.024) and No-load Lq (05.072) may not correspond to the d and q axis respectively. The test is completed and all the parameters saved to non-volatile memory in the drive, but the user should note that the measured results may not be correct. It should be noted that this trip is not produced if sensorless mode is selected and active (i.e. Sensorless Mode Active (03.078) = 1).
Inductance.004 | During auto-tune test 1 when position feedback is being used (i.e. Sensorless Mode Active (03.078) = 0), the direction of the flux in the motor must be detected by the change of inductance with different currents. This trip is initiated if the change cannot be detected.

If Sensorless Mode Active (03.078) = 1 then trips Autotune 1, Autotune 2 and Autotune 7 are disabled.

Parameter | 05.013 Minimal Movement Phasing Test Mode
--- | ---
Short description | Minimal Movement Phasing Test Mode
Mode | RFC‑S
Minimum | -3 | Maximum | 1
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
-3 | Free x4
-2 | Free x3
-1 | Free x2
0 | Free
1 | Constrained

If position feedback is being used, i.e. Sensorless Mode Active (03.078) = 0, it is necessary to define the relationship between the motor magnet flux and the position feedback angle with Position Feedback Phase Angle (03.025) (or M2 Position Feedback Phase Angle (21.020) for motor map 2). This can be measured during auto-tuning with a rotating or stationary test. Minimal Movement Phasing Test Mode (05.013) and Minimal Movement Phasing Test Angle (05.016) are used to define the operation of the stationary test. It is also possible to perform the stationary test on drive enable to calculate Position Feedback Phase Angle (03.025), see Phasing Test On Enable (05.014) for details. If position feedback is not being used, Sensorless Mode Active (03.078) = 1, then Position Feedback Phase Angle (03.025) is not relevant, and so these parameters are also not relevant.

If Minimal Movement Phasing Test Angle (05.016) is left at its default value of zero the stationary test uses motor inductance measurement to locate the magnet flux in the motor to calculate Position Feedback Phase Angle (03.025). The inductance measurement test does not cause any deliberate movement of the motor during the test, but does rely on the motor being salient under no-load conditions. If the motor is non-salient, i.e. the ratio between the d and q inductance is too small (see Inductance) then inductance measurement cannot be used for the stationary test.

As an alternative to inductance measurement, a test referred to as a minimal movement test, that causes a small movement of the motor, can be used instead. The minimal movement test does not depend on motor saliency, but is not as accurate as the inductance based measurement with high saliency motors where Volts Per 1000rpm (05.033) / (Number Of Motor Poles (05.011) x (No-load Lq (05.072) - (Ld (05.024)) x Rated Current (05.007)) is less than 200. This means this test cannot be used with a synchronous reluctance motor and it is unlikely it can be used with a high-saliency permanent magnet motor. The minimal movement test can be used even if the motor is free to move, or if it is constrained by a mechanical brake provided the mechanical system allows sufficient motor movement. For the test to be reliable it is suggested that the position feedback changes by at least 75 counts during the test. If the motor is unconstrained and free to rotate Minimal Movement Phasing Test Mode (05.013) should be at its default value of Free (0) or set to a negative value (i.e. Free x2 (-1), Free x3 (-2) or Free x4 (-3)). If the motor is not free to move it should be set to Constrained (1).

To select the minimal movement test, instead of the inductance measurement, Minimal Movement Phasing Test Angle (05.016) should be set to a non-zero value to define the peak to peak movement required during the test in 0.001o units. For example: if the position feedback has a resolution of 16384 counts per revolution (i.e. a 4096 ppr AB encoder), then for a movement of 75 counts the required angle is 360o x 75 / 16384 = 1.648o.

If the motor is free to rotate (Minimal Movement Phasing Test Mode (05.013) = Free (0)) it is advisable to use an angle of at least 1.000o to prevent non-linear effects such as motor cogging from affecting the result. If the motor is constrained (Minimal Movement Phasing Test Mode (05.013) = Constrained (1)) then the required movement will need to be set to a lower value as it is unlikely that the drive will be able to achieve a large angular movement against the brake, and so a higher resolution position feedback device may be required. If the motor is constrained an angle of at least 0.050o should be used where possible. The minimal movement test does not apply a static torque, but an alternating torque, so there should be no net slip against the brake. If the required movement defined by Minimal Movement Phasing Test Angle (05.016) is too high the brake may prevent this and the test will fail. (If a linear position feedback device is being used 360o corresponds to one pole pitch.)

When the minimal movement phasing test is used with an unconstrained motor a short series of torque pulses are applied to vibrate the motor. The test will progressively increase the length of the pulses and the level of torque applied until the required movement is achieved. The steps represent 1%, 2%, 3%, 6%, 12%, 25%, 50% and 100% of the maximum pulse width and torque, where the maximum is rated torque for 16ms. Minimal Movement Phasing Test Mode (05.013) selects the type of test and also if a negative value is selected it will extend the length of the pulses used for the unconstrained motor test. Free x2 (-1) increase the pulse length by a factor of 2, Free x3 (-2) by a factor of 3 and Free x4 (-3) by a factor of 4. Using longer pulses means that less torque is required to achieve the required movement which makes the test quieter. The same test is used during auto-tuning or when the position feedback phase angle is measured on drive enable.

The following trips are possible which will terminate the test and not update Position Feedback Phase Angle (03.025).

Trip | Reason
Inductance.003 | The ratio of Ld and Lq is too small. See Inductance trip.
Inductance.004 | The saturation characteristic of the motor cannot be measured.
Autotune 1.004 | The required angular movement could not be achieved during the minimal movement test.
Autotune 1.006 | During auto-tuning the two minimal movement tests carried out did not give consistent results.
Autotune 1.009 | The required movement could not be achieved when trying to check the polarity of the results during a constrained test.

It should be noted that the minimal movement test system can be used when position feedback is via the P1 or P2 interfaces on the drive or via a position feedback interface from an option module. However, if the position feedback is via an option module any filtering applied to the speed feedback by the option module must be disabled. This does not apply to the drive position feedback interfaces because the filtering effect of P1 Feedback Filter (03.042) is automatically bypassed during the test.

Parameter | 05.014 Phasing Test On Enable
--- | ---
Short description | Defines a when a stationary test is performed to calculate the Position Feedback Phase Angle
Mode | RFC‑S
Minimum | 0 | Maximum | 4
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
0 | Disabled
1 | Short
2 | Short Once
3 | Long
4 | Long Once

Phasing Test On Enable (05.014) can be used to get the drive to perform a phasing angle test when it is enabled. This test can be used when a non-absolute encoder is used for motor control feedback. The phasing test will measure and modify Position Feedback Phase Angle (03.025), so that the correct offset is applied to run the motor with the non-absolute encoder. Note that the value is not saved in drive non-volatile memory. A test is only carried out when sensorless mode is not active (i.e. Sensorless Mode Active (03.078) = 0). The test can be selected to occur after power-up and each time the position feedback is re-initialised. It is not necessary to perform the test on every enable, but this can be selected if required. The table below shows the possible options depending on the test angle defined in Minimal Movement Phasing Test Angle (05.016) and the test mode defined by Minimal Movement Phasing Test Mode (05.013). The table gives the length of the test and when it is performed.

Phasing Test On Enable (05.014) | Test Angle = 0.00, Test Mode = N/A | Test Angle is not 0.00, Test Mode = 1 (Constrained) | Test Angle is not 0.00, Test Mode < 1 (Free)
Disabled (0) | No phasing test is carried out on enable. | No phasing test is carried out on enable. | No phasing test is carried out on enable.
Short (1) | 0.4s on every enable. | 4s on every enable. | 1s on every enable.
Short Once (2) | 0.4s on first enable after power-up and initialisation of position feedback. | 4s on first enable after power-up and initialisation of position feedback. | 1s on first enable after power-up and initialisation of position feedback
Long (3) | 2.5s on every enable. | 4s on every enable. | 1s on every enable.
Long Once (3) | 2.5s on first enable after power-up and initialisation of position feedback. | 4s on first enable after power-up and initialisation of position feedback. | 1s on first enable after power-up and initialisation of position feedback.

Minimal Movement Phasing Test Angle (05.016) is zero
The motor inductance is measured to determine the position of the rotor flux. It is recommended that the long test is used as this reduces measurement errors. The long test should always be used when the motor is not constrained during the test (i.e. a motor without a mechanical brake), or with motors that have a high level of saliency even if they are held in position. It should be noted that the motor inductances ( Ld (05.024) and No-load Lq (05.072) ) are checked before the test is carried out, and if the difference is not sufficient (see Inductance) then the drive will trip. Therefore, if the motor inductances have not been measured with auto-tuning or changed from their default values of zero the drive will trip when the drive is enabled. This test, in common with the stationary auto-tune test, cannot be used with commutation only type feedback, i.e. when P1 Device Type (03.038) is set to Commutation Only. Most motors have a positive saturation characteristic so that increasing the current in the flux axis increases motor saturation. It is possible with some motor designs for the characteristic to be reversed. If this is the case the phase angle measurement on enable will produce a value that is 180o from the real value. If this is the case Inverted Saturation Characteristic (05.070) should be set to one.

Minimal Movement Phasing Test Angle (05.016) is non-zero
A minimal movement test is used to determine the position of the rotor flux. See Minimal Movement Phasing Test Mode (05.013) for details. This test cannot be used with any position feedback devices that use commutation signals (i.e. AB Servo, FD Servo, FR Servo, SC Servo or Commutation Only).

Parameter | 05.016 Minimal Movement Phasing Test Angle
--- | ---
Short description | Minimal Movement Phasing Test Angle
Mode | RFC‑S
Minimum | 0.000 | Maximum | 25.000
Default | 0.000 | Units | °
Type | 16 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 3
Coding | RW

If this parameter is set to a non-zero value then the drive will perform a minimal movement autotune whenever a stationary autotune is selected in Auto-tune (05.012) or phasing test on enable is selected in Phasing Test On Enable (05.014).

See Minimal Movement Phasing Test Mode (05.013) for more information.

Parameter | 05.017 Stator Resistance
--- | ---
Short description | Defines the resistance of the motor stator
Mode | RFC‑S
Minimum | 0.000000 | Maximum | 1000.000000
Default | 0.000000 | Units | Ω
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 6
Coding | RW

The motor parameters used by the drive are derived from the star connected per phase equivalent circuit of a permanent magnet motor shown below. Although one value of inductance is shown, for many synchronous motors the flux or direct axis inductance (Ld) and the torque or quadrature axis inductance (Lq) can be significantly different. Also the q axis inductance can vary significantly with motor current.

Stator Resistance (05.017) = R

Ld (05.024) = L in the d (flux) axis

No-load Lq (05.072) = L in the q (torque) axis with no current in the motor

Lq At The Defined Iq Current (05.078) = L in the q axis with Id = 0 and Iq = Lq At The Defined Iq Current (05.078)

Lq At The Defined Id Current (05.084) = L in the q axis with Id = Lq At The Defined Id Current (05.084) and Iq = 0.

Stator Resistance (05.017) is used as described in the table below.

Function | Details
Control above low speeds with sensorless control | The stator resistance is used by the algorithm that determines the rotor position.
Current controller integral gain set-up | During auto-tuning the stator resistance is used in the calculation of the current controller integral gain.
High performance current control | If high performance current control is selected the stator resistance is used in the control for both d and q axis current.

Although the maximum value of this parameter is 1000ohms the maximum resistance is limited to (VM_DC_VOLTAGE / √2) / Full Scale Current Kc (11.061). If the parameter is set to a higher value a Resistance.001 trip is initiated.

Parameter | 05.018 Maximum Switching Frequency
--- | ---
Short description | Defines the maximum switching frequency that can be used by the drive
Mode | RFC‑S
Minimum | 0 | Maximum | VM_SWITCHING_FREQUENCY
Default | 4 | Units | kHz
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE, VM

Value | Text
0 | 2
1 | 3
2 | 4
3 | 6
4 | 8
5 | 12
6 | 16

Maximum Switching Frequency (05.018) should be set to the required PWM switching frequency. The drive inverter will operate at this frequency unless the inverter temperature becomes too hot. Under these conditions the drive will reduce the switching frequency in an attempt to avoid tripping (see Auto-switching Frequency Change (05.035) ). The actual switching frequency is shown in Switching Frequency (05.037). The switching frequency has a direct effect on the sample rate for the current controllers (see Current Controller Kp Gain (04.013)). All other control tasks are at a fixed rate.

Parameter | 05.021 Mechanical Load Test Level
--- | ---
Short description | Mechanical Load Test Level
Mode | RFC‑S
Minimum | 0 | Maximum | 100
Default | 0 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Auto-tune (05.012).

Parameter | 05.022 Enable High Speed Mode
--- | ---
Short description | Set to 1 to enable high speed mode
Mode | RFC‑S
Minimum | -2 | Maximum | 2
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
-2 | Limit
-1 | Limit (Servo)
0 | Disable
1 | Enable (Servo)
2 | Enable

This parameter is primarily intended to set up the drive to operate with low saliency motors where the back-emf could damage the drive if the drive is disabled when the motor is running at high speed. It is recommended that Saliency Torque Control Select (05.065) is set to Auto so that the drive automatically selects the appropriate control mode for the motor. There are four functions related to this parameter and Saliency Torque Control Select (05.065):

1. Production of additional torque from motor saliency. In low-saliency PM motors this is sometimes referred to as phase advance.
2. Motor voltage control to limit the motor voltage to the required level.
3. Limiting the torque produced when the motor is operating with the voltage constrained by the drive (i.e. motor voltage control limit active) to prevent oscillations or loss of control. This is referred to as the voltage-based torque limit.
4. Preventing damage to the drive on disable due to high voltages produced by the rotor magnet flux.

The effect of Enable High Speed Mode (05.022) is overridden as described in the table below.

Active Saliency Torque Mode (05.066) | Override | Comments
Disabled (0) | None |
Low (1) | Limit (Servo) | If Enable High Speed Mode (05.022) is left at its default value of Disabled, then saliency torque can be produced and the motor voltage limit is enabled. An Over Speed.1 trip is initiated if the motor speed exceeds the level that could damage the drive if it is disabled. The limit to prevent the motor from operating beyond its maximum torque limit at higher speeds is not active, but can be enabled by selecting Limit mode with Enable High Speed Mode (05.022). If Enable High Speed Mode (05.022) has any other value then it operates as described.
High (2) | Limit | The magnet flux level in a high saliency motor is unlikely to produce enough voltage even at maximum speed that could damage the drive. If this is the case then the drive will initiate an Over Speed.1 trip if the voltage becomes too high. This type of motor is likely to operate close to its maximum torque at higher speeds, and so the limit to prevent the motor from operating beyond its maximum torque limit is always active. This override always applies and Enable High Speed Mode (05.022) has no effect.
Sync Reluctance (3) | Limit | There is no magnet flux, and so the motor cannot damage the drive. As Ke is zero the trip to prevent motor damage at high speeds is inactive. It is necessary to prevent this type of motor from exceeding its maximum torque limit at higher speeds, and so this limit function is always active. This override always applies and Enable High Speed Mode (05.022) has no effect.

Care must be taken when controlling a permanent magnet motor and high speed mode is not set to Disable (0) to avoid damaging the drive. The voltage produced by the magnet flux is proportional to speed. For high speed operation the drive must apply currents to the motor to counter-act the flux produced by the magnets. It is possible to operate the motor at very high speeds that would give a very high motor terminal voltage, but this voltage is prevented by the action of the drive. If however, the drive is disabled (or tripped) when the motor voltages would be higher than the rating of the drive without the currents to counter-act the flux from the magnets, it is possible to damage the drive. If high speed mode is enabled the motor speed must be limited to the levels given in the table below unless an additional hardware protection system is used to limit the voltages applied to the drive output terminals to a safe level.

Drive voltage rating | Maximum motor speed (rpm) | Maximum safe line to line voltage at the motor terminals (V r.m.s.)
200 | 400 x 1000 / (Ke x √2) | 400 / √2
400 | 800 x 1000 / (Ke x √2) | 800 / √2
575 | 955 x 1000 / (Ke x √2) | 955 / √2
690 | 1145 x 1000 / (Ke x √2) | 1145 / √2

Where Ke is defined by Volts Per 1000rpm (05.033) (or M2 Volts Per 1000rpm (21.030) if motor map 2 is selected). Note that if Ke is set to zero (for use with a synchronous reluctance motor) there is no magnet flux, so it is not possible to damage the drive when it is disabled at high speed.

Disabled (0):
The motor flux is not modified to limit the motor voltage to the level defined by Rated Voltage (05.009). The motor voltage will increase as the speed is increased until the motor line to line voltage x √2 is equal to the d.c. link voltage (D.c. Bus Voltage (05.005)). It will not be possible to further increase the speed significantly. This mode is safe because the motor voltage with no current flowing in the motor cannot exceed a level that can damage the drive provided Position Feedback Phase Angle (03.025) is correct for the motor. Note that if Position Feedback Phase Angle (03.025) is modified by the user to change the flux level in the motor then it is possible to damage the drive on disable as described above.

Limit (Servo) (-1):
The motor flux is modified to limit the motor voltage to the level defined by Rated Voltage (05.009). An Over Speed.1 trip is initiated if the measured motor speed exceeds the levels defined in the table above to protect the drive. This mode is intended for dynamic servo type applications and the drive will not restrict the torque requested from the motor to prevent the motor from exceeding its voltage based torque limit. If the motor is operated at or close to this limit it can become unstable.

Limit (-2):
This is similar to Limit (Servo) mode except that the motor torque is restricted to prevent the drive from operating close to, or beyond, the voltage based torque limit of the motor. This prevents the motor from operating in a region where it could become unstable.

Enable (Servo) (1):
This is similar to Limit (Servo) mode except that a trip is not produced if the motor speed exceeds the maximum safe level. An indication that cannot be cleared is stored in Potential Drive Damage Conditions (10.106) and saved on power-down. The motor manufacturer should always be consulted before using this mode as care must be taken not to de-magnetise the motor.

Enable (2):
This is similar to Enable (Servo) mode except that the limit to prevent the motor from exceeding its voltage based torque limit is active.

Parameter | 05.024 Ld
--- | ---
Short description | Defines the inductance in the flux axis
Mode | RFC‑S
Minimum | 0.000 | Maximum | 500.000
Default | 0.000 | Units | mH
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 3
Coding | RW

Flux or direct axis inductance.

Ld (05.024) is used as described in the table below.

Function | Details
Current controller gain set-up | During auto-tuning Ld is used in calculating the current controller gains.
High performance current control | If high performance current control is selected (Current Controller Mode (04.030) =1) Ld is used by the controller in d axis.
Low speed operation with sensorless control | If injection mode is used (RFC Low Speed Mode (05.064) = 0) for low speed operation Ld defines the gain of the system.
Voltage controller gain | Ld is used in deriving the gain of the controller which controls the motor voltage at high speed.
Motor torque limit | Ld is used in defining the torque limit for high saliency motors.

The torque or quadrature axis inductance (Lq) is defined in other parameters. See No-load Lq (05.072) for more details.

Note that both the d and q axis inductance of a synchronous reluctance motor change significantly from their no load values as current is applied. With no current in a permanent magnet motor Ld is close to the lowest inductance seen in the motor and is therefore used to set up the current controllers to ensure stability. However, the no-load value of Ld in a synchronous reluctance motor is too high to be used for this purpose. Also it is not possible to measure Ld in a synchronous reluctance motor with current in the d axis (i.e., to measure the value with current) because the motor is likely to move. Therefore during auto-tuning Lq is measured with Iq equal to rated current as a substitute for no-load Ld. This will give a value that is similar to the lowest value of Ld seen when the motor is loaded.

Parameter | 05.026 High Dynamic Performance Enable
--- | ---
Short description | Set to 1 to enable High Dynamic Performance
Mode | RFC‑S
Minimum | 0 | Maximum | 1
Default | 0 | Units |
Type | 1 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

Whatever the value of High Dynamic Performance Enable (05.026) a feed-forward term based on the estimated level of magnet flux in a permanent magnet motor and the speed is used to improve the performance of the current controllers and to avoid transients during spinning start. However, if High Dynamic Performance Enable (05.026) = 1 additional feed-forward terms are provided to remove the effects of cross-coupling between the flux and torque axes. This improves the performance of the current controllers under dynamic conditions at high speeds. It should be noted that High Dynamic Performance Enable (05.026) has no effect if sensorless control is active (i.e. Sensorless Mode Active (03.078) = 1).

Parameter | 05.027 Flux Control Gain
--- | ---
Short description | Flux Control Gain
Mode | RFC‑S
Minimum | 0.1 | Maximum | 100.0
Default | 1.0 | Units |
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

Flux Control Gain (05.027) refers to the gain of the controller which limits the motor voltage. If this is set to the default value of unity the system that controls the motor voltage is automatically set up based on the motor parameters to give stable operation under most conditions. Some motors which have concentrated windings can cause significant harmonic currents which in turn disturb the voltage controller at higher speeds where the voltage controller is active to limit the motor voltage. To reduce this effect the gain can be reduced. The gain can also be increased for applications with fast acceleration to improve the response of the voltage controller in limiting the motor voltage.

Parameter | 05.031 Voltage Controller Gain
--- | ---
Short description | Defines the proportional gain of the d.c. link voltage controller
Mode | RFC‑S
Minimum | 1 | Maximum | 30
Default | 1 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

Voltage Controller Gain (05.031) can be used to modify the proportional gain of the d.c. link voltage controller used for standard ramp and supply loss control.

Parameter | 05.032 Torque Per Amp
--- | ---
Short description | Defines the torque per amp constant (Kt) for the motor
Mode | RFC‑S
Minimum | 0.00 | Maximum | 500.00
Default | 1.60 | Units | Nm/A
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 2
Coding | RW, BU

Torque Per Amp (05.032) is used for automatic speed controller gain set up and to calculate the inertia in autotune tests 3 and 4, and so the correct value for the motor should be entered if these features are used. This value can be calculated by dividing the motor rated torque in Nm by the rated current in r.m.s. amps.

Parameter | 05.033 Volts Per 1000rpm
--- | ---
Short description | Volts per 1000rpm
Mode | RFC‑S
Minimum | 0 | Maximum | 10000
Default | 98 | Units | V
Type | 16 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

Volts Per 1000rpm (05.033) defines the r.m.s. line voltage produced by the motor flux at 1000rpm, i.e. running at this speed with no current in the motor. For a synchronous reluctance motor this parameter must be set to zero.

Volts Per 1000rpm (05.033) is used as described in the table below.

Function | Details
Voltage feed-forwards | Provides voltage feed-forwards for the current control system.
Over-speed protection | Ke is used to determine the trip speed if Enable High Speed Mode (05.022) is set to Limit mode
Rated torque angle | If the drive defines Rated Torque Angle (05.089) Ke is used in the calculation.
Spin start | Ke is used to define a threshold to detect when the motor is at standstill and spin start is not possible with sensorless operation.

Parameter | 05.035 Auto-switching Frequency Change
--- | ---
Short description | Defines auto-switching frequency control with thermal model
Mode | RFC‑S
Minimum | 0 | Maximum | 2
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
0 | Enabled
1 | Disabled
2 | No Ripple Detect

The inverter can be damaged if the temperature is too high. The inverter can also be damaged or the lifetime of the power devices reduced, if the temperature ripple of the devices is too high. Auto-switching Frequency Change (05.035) defines the action taken if the drive inverter becomes too hot or the temperature ripple becomes too high. The inverter temperature is provided in Inverter Temperature (07.034).

Enabled:
If the inverter becomes too hot or the ripple temperature is higher than the level defined by Maximum Inverter Temperature Ripple (05.039) the switching frequency is reduced in an attempt to prevent tripping.

Disabled:
The switching frequency is not reduced, and so the drive will trip on OHt Inverter.100 if the inverter is too hot or the temperature ripple is too high.

No Ripple Detect:
The switching frequency is only reduced if the inverter temperature is too high. If the temperature ripple exceeds the level defined by Maximum Inverter Temperature Ripple (05.039) then the switching frequency is not reduced and the drive will trip on OHt Inverter.100.

The switching frequency is changed in steps defined by Auto-switching Frequency Step Size (05.036). For example with a switching frequency of 16kHz and a step size of two, the frequency will be reduced to 8kHz, then 4kHz etc. Minimum Switching Frequency (05.038) defines the minimum switching frequency that the system will attempt to use. If the switching frequency needs to switch to a lower level, then the drive will trip on OHt Inverter.100. If Minimum Switching Frequency (05.038) is changed the new value will only become active when Switching Frequency (05.037) is at or above the minimum value.

Parameter | 05.036 Auto-switching Frequency Step Size
--- | ---
Short description | Auto-switching frequency reduction step size
Mode | RFC‑S
Minimum | 1 | Maximum | 2
Default | 2 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Auto-switching Frequency Change (05.035).

Parameter | 05.037 Switching Frequency
--- | ---
Short description | Displays the current switching frequency used by the drive
Mode | RFC‑S
Minimum | 0 | Maximum | 6
Default |  | Units | kHz
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, TE, ND, NC, PT

Value | Text
0 | 2
1 | 3
2 | 4
3 | 6
4 | 8
5 | 12
6 | 16

Shows the actual inverter switching frequency after the auto-change function.

Parameter | 05.038 Minimum Switching Frequency
--- | ---
Short description | Minimum Switching Frequency
Mode | RFC‑S
Minimum | 0 | Maximum | VM_MIN_SWITCHING_FREQUENCY
Default | 2 | Units | kHz
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE, VM

Value | Text
0 | 2
1 | 3
2 | 4
3 | 6
4 | 8
5 | 12
6 | 16

See Auto-switching Frequency Change (05.035).

Parameter | 05.039 Maximum Inverter Temperature Ripple
--- | ---
Short description | Maximum Inverter Temperature Ripple
Mode | RFC‑S
Minimum | 20 | Maximum | 60
Default | 60 | Units | °C
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

Maximum Inverter Temperature Ripple (05.039) defines the maximum inverter temperature ripple which the drive uses to manage the inverter stage temperature. On reaching the maximum inverter temperature ripple the drive will reduce its switching frequency using Maximum Switching Frequency (05.018), Minimum Switching Frequency (05.038) and Auto-switching Frequency Step Size (05.036) where allowable. If the drive is unable to reduce its switching frequency and the temperature continues to exceed the maximum inverter temperature ripple a OHt Inverter.100 trip will be generated. See Auto-switching Frequency Change (05.035).

Parameter | 05.041 Voltage Headroom
--- | ---
Short description | Voltage Headroom
Mode | RFC‑S
Minimum | 0 | Maximum | 20
Default | 0 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

When the motor voltage controller limit is active, the voltage applied to the motor is always limited by Rated Voltage (05.009). When Voltage Headroom (05.041) is set to its default value of zero the output voltage of the inverter is also limited to a level equivalent to full modulation, which is the supply voltage minus voltage drops within the inverter itself. Depending on the relative values of the supply voltage and Rated Voltage (05.009) there may be some headroom between the rated voltage limit and the maximum possible voltage from the inverter to allow the current control system to give good dynamic performance. In some applications it is useful to enforce some headroom between the maximum allowed motor voltage and the inherent limit imposed by the inverter. If the supply voltage is known this can be done by setting Rated Voltage (05.009) to a suitable value below the supply voltage level, however, it is more convenient to set Rated Voltage (05.009) to the actual rated voltage of the motor, and to use Voltage Headroom (05.041) to enforce the voltage headroom. This parameter can be used to increase the headroom between the maximum modulation limit and the maximum motor voltage from zero up to 20% of the maximum modulation limit. For example, if the supply voltage is 400V then a value of 10% will give a voltage headroom of approximately 40V.

Parameter | 05.042 Reverse Output Phase Sequence
--- | ---
Short description | Set to 1 to reverse the sequence on the output phases
Mode | RFC‑S
Minimum | 0 | Maximum | 1
Default | 0 | Units |
Type | 1 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

If Reverse Output Phase Sequence (05.042) = 0 the output phase sequence is U-V-W when Output Frequency (05.001) is positive and W-V-U when Output Frequency (05.001) is negative. If Reverse Output Phase Sequence (05.042) = 1 the output phase sequence is reversed so that the phase sequence in W-V-U for positive frequencies and U-V-W for negative frequencies.

Parameter | 05.044 Stator Temperature Source
--- | ---
Short description | Defines the source of the stator temperature
Mode | RFC‑S
Minimum | 1 | Maximum | 6
Default | 1 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
1 | User
2 | P1 Drive
3 | P1 Slot1
4 | P1 Slot2
5 | P1 Slot3
6 | P1 Slot4

The stator temperature can be used to compensate for changes in stator resistance. See Stator Temperature Coefficient (05.047). Stator Temperature Source (05.044) is used to select the source for the stator temperature measurement.

Stator Temperature Source (05.044) | Source | Comments
0 | Analog Input 3 Thermistor Temperature (07.050) | Analog input 3 must be set up for the correct temperature feedback device
1 | User Stator Temperature (05.045) | The user can provide a stator temperature value. If an alternative feedback device is to be used or the user provides an algorithm to model the stator temperature.
2 | P1 Thermistor Temperature (03.122) | P1 position feedback interface must be set up for the correct temperature feedback device
3-6 | Option slot P1 Thermistor Temperature (xx.122) | A position feedback category option module must be fitted and the P1 position feedback must be set up for the correct temperature feedback device

Parameter | 05.045 User Stator Temperature
--- | ---
Short description | Defines the stator temperature as set by the user
Mode | RFC‑S
Minimum | -50 | Maximum | 300
Default | 0 | Units | °C
Type | 16 Bit Volatile | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Stator Temperature Source (05.044).

Parameter | 05.046 Stator Temperature
--- | ---
Short description | Displays the temperature of the motor stator
Mode | RFC‑S
Minimum | -50 | Maximum | 300
Default |  | Units | °C
Type | 16 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT

See Stator Temperature Source (05.044).

Parameter | 05.047 Stator Temperature Coefficient
--- | ---
Short description | Defines the coefficient used to calculate the temperature of the motor stator
Mode | RFC‑S
Minimum | 0.00000 | Maximum | 0.10000
Default | 0.00390 | Units | 1/°C
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 5
Coding | RW

Temperature Compensated Stator Resistance (05.050) shows the stator resistance from the active motor that is being used by the drive for motor control. If Enable Stator Compensation (05.049) = 0 and motor 1 is selected then Temperature Compensated Stator Resistance (05.050) is equal to Stator Resistance (05.017). If Enable Stator Compensation (05.049) = 1 the value of Stator Resistance (05.017) is not changed, but Temperature Compensated Stator Resistance (05.050) is derived as follows:

α = Stator Temperature Coefficient (05.047) and this is the temperature coefficient for the stator winding at 20oC as a proportion of the resistance per degree C.

Temperature Compensated Stator Resistance (05.050) = Stator Resistance (05.017) x [1 + (Stator Temperature (05.046) – 20oC) x α] / [1 + (Stator Base Temperature (05.048) - 20oC) x α]

Stator Resistance (05.017) and Stator Base Temperature (05.048) can be set up by the user with the stator resistance at a given temperature. The preferred method is for the Stator Resistance (05.017) to be measured and set up using the auto-tuning system (See Auto-tune (05.012)). If Enable Stator Compensation (05.049) = 1 when the auto-tuning is carried out the Stator Base Temperature (05.048) will be updated automatically with Stator Temperature (05.046).

The temperature compensation system can only function correctly if the Stator Temperature Coefficient (05.047) is set up correctly. The default value is suitable for copper or aluminium windings and should not need to be adjusted for these materials provided the temperature measurement is a reasonable measure of the winding temperature. If the temperature measurement is not closely coupled to the winding it may be necessary to adjust Stator Temperature Coefficient (05.047) for correct compensation.

Parameter | 05.048 Stator Base Temperature
--- | ---
Short description | Defines the base temperature used to calculate the temperature of the motor stator
Mode | RFC‑S
Minimum | -50 | Maximum | 300
Default | 0 | Units | °C
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Stator Temperature Coefficient (05.047).

Parameter | 05.049 Enable Stator Compensation
--- | ---
Short description | Set to 1 to enable stator compensation
Mode | RFC‑S
Minimum | 0 | Maximum | 1
Default | 0 | Units |
Type | 1 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Stator Temperature Coefficient (05.047).

Parameter | 05.050 Temperature Compensated Stator Resistance
--- | ---
Short description | Final stator resistance value used by the drive including temperature compensation
Mode | RFC‑S
Minimum | 0.000000 | Maximum | 1000.000000
Default |  | Units |
Type | 32 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 6
Coding | RO, ND, NC, PT

Temperature Compensated Stator Resistance (05.050) shows the stator resistance value for the active motor that is being used by the drive including the effect of temperature compensation.

Parameter | 05.051 Rotor Temperature Source
--- | ---
Short description | Defines the source of the rotor temperature
Mode | RFC‑S
Minimum | 1 | Maximum | 6
Default | 1 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
1 | User
2 | P1 Drive
3 | P1 Slot1
4 | P1 Slot2
5 | P1 Slot3
6 | P1 Slot4

The rotor temperature can be used to compensate for changes in rotor resistance that affects the motor slip and hence the rated speed in Open-loop or RFC-A mode, or the magnet flux that affects motor torque in RFC-S mode. See Rotor Temperature Coefficient (05.054) for details. Rotor Temperature Source (05.051) is used to select the source for the rotor temperature measurement.

Rotor Temperature Source (05.051) | Source | Comments
0 | Analog Input 3 Thermistor Temperature (07.050) | Analog input 3 must be set up for the correct temperature feedback device
1 | User Rotor Temperature (05.052) | The user can provide a rotor temperature value if an alternative feedback device is to be used or the user provides an algorithm to model the rotor temperature
2 | P1 Thermistor Temperature (03.122) | P1 position feedback interface must be set up for the correct temperature feedback device
3-6 | Option Slot P1 Thermistor Temperature (xx.122) | A position feedback category option module must be fitted and the P1 position feedback must be set up for the correct temperature feedback device

Parameter | 05.052 User Rotor Temperature
--- | ---
Short description | Defines the temperature of the motor as set by the user
Mode | RFC‑S
Minimum | -50 | Maximum | 300
Default | 0 | Units | °C
Type | 16 Bit Volatile | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Rotor Temperature Source (05.051).

Parameter | 05.053 Rotor Temperature
--- | ---
Short description | Displays the temperature of the motor rotor
Mode | RFC‑S
Minimum | -50 | Maximum | 300
Default |  | Units | °C
Type | 16 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT

See Rotor Temperature Source (05.051).

Parameter | 05.054 Rotor Temperature Coefficient
--- | ---
Short description | Defines the coefficient used to calculate the temperature of the rotor
Mode | RFC‑S
Minimum | 0.00000 | Maximum | 0.10000
Default | 0.00100 | Units | 1/°C
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 5
Coding | RW

The flux produced by the magnets in a permanent magnet motor varies with rotor temperature, and this in turn affects the relationship between the motor current and torque. (Note that this effect is not relevant for synchronous reluctance motors which have no magnets, and so the rotor temperature compensation system should not be used with this type of motor.) Rotor Temperature Compensation (05.057) shows the compensation factor that is applied to convert from the torque reference to the torque producing current reference. If Enable Rotor Compensation (05.056) = 0 no compensation is applied in converting from the torque reference to the torque producing current reference (i.e. Rotor Temperature Compensation (05.057) = 1.000). If Enable Rotor Compensation (05.056) = 1 then Rotor Temperature Compensation (05.057) is calculated as follows:

Rotor Temperature Compensation (05.057) = 1 – [(Rotor Temperature (05.053) – Rotor Base Temperature (05.055)) x Rotor Temperature Coefficient (05.054)]
The default value of Rotor Temperature Coefficient (05.054) is a typical value for the magnets used in most permanent magnet motors. However, if the thermal coupling between the rotor and the temperature measuring device is poor it may be necessary to adjust Rotor Temperature Coefficient (05.054) to give better compensation.

Parameter | 05.055 Rotor Base Temperature
--- | ---
Short description | Defines the base temperature used to calculate the temperature of the rotor
Mode | RFC‑S
Minimum | -50 | Maximum | 300
Default | 0 | Units | °C
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Rotor Temperature Coefficient (05.054).

Parameter | 05.056 Enable Rotor Compensation
--- | ---
Short description | Set to 1 to enable rotor compensation
Mode | RFC‑S
Minimum | 0 | Maximum | 1
Default | 0 | Units |
Type | 1 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Rotor Temperature Coefficient (05.054).

Parameter | 05.057 Rotor Temperature Compensation
--- | ---
Short description | Factor to convert from torque to current based on rotor temperature
Mode | RFC‑S
Minimum | 0.000 | Maximum | 2.000
Default |  | Units |
Type | 16 Bit Volatile | Update Rate | Background
Display Format | Standard | Decimal Places | 3
Coding | RO, ND, NC, PT

Rotor Temperature Compensation (05.057) shows the conversion factor used between the torque reference and the torque producing current.

Parameter | 05.059 Maximum Deadtime Compensation
--- | ---
Short description | Shows the deadtime compensation used to compensate for dead-time effects in the inverter
Mode | RFC‑S
Minimum | 0.000 | Maximum | 10.000
Default | 0.000 | Units | µs
Type | 16 Bit Volatile | Update Rate | Background Read
Display Format | Standard | Decimal Places | 3
Coding | RO, NC, PT

Maximum Deadtime Compensation (05.059) is used to compensate for dead-time effects in the inverter. This level of compensation is used when the drive output current is above Current At Maximum Deadtime Compensation (05.060). Both of these values, related to dead-time compensation, are measured during auto-tuning and cannot be set by the user. Once auto-tuning has been carried out in Open-loop, RFC-A or RFC-S mode Maximum Deadtime Compensation (05.059) and Current At Maximum Deadtime Compensation (05.060) are retained by the drive even if defaults are loaded or the drive mode is changed.

There may be a slight variation in the values measured each time the test is performed particularly if the temperature of the power devices changes between tests. The values are normally measured at 6kHz (unless the thermal model reduces the switching frequency during the test). The system will attempt to modify the compensation when other switching frequencies are used during normal operation. The dead-time compensation system improves the linearity of the drive output at low current levels and will help to prevent light load instability in Open-loop mode and give better current waveforms at phase current zero crossings in RFC-A and RFC-S modes. The compensation may not be exact as the temperature and switching frequency change from the levels used during auto-tune, however the inverter linearity is improved significantly especially at higher switching frequencies, and so dead-time compensation gives much improved performance.

Although it is not recommended, it is possible to disable dead-time compensation by setting Disable Deadtime Compensation (05.061) = 1.

If auto-tuning is never performed (i.e., Maximum Deadtime Compensation (05.059) = 0) then a fixed value defined for the particular power stage is used for Maximum Deadtime Compensation (05.059) and Current At Maximum Deadtime Compensation (05.060) is assumed to be zero. This gives dead-time compensation that may prevent light load instability in Open-loop mode, but is unlikely to improve current linearity at low current levels.

Parameter | 05.060 Current At Maximum Deadtime Compensation
--- | ---
Short description | Current at which maximum deadtime compensation is applied
Mode | RFC‑S
Minimum | 0.00 | Maximum | 100.00
Default | 0.00 | Units | %
Type | 16 Bit Volatile | Update Rate | Background Read
Display Format | Standard | Decimal Places | 2
Coding | RO, NC, PT

See Maximum Deadtime Compensation (05.059).

Parameter | 05.061 Disable Deadtime Compensation
--- | ---
Short description | Disable Deadtime Compensation
Mode | RFC‑S
Minimum | 0 | Maximum | 1
Default | 0 | Units |
Type | 1 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Maximum Deadtime Compensation (05.059).

Parameter | 05.063 Sensorless Mode Current Ramp
--- | ---
Short description | Sensorless Mode Current Ramp
Mode | RFC‑S
Minimum | 0.00 | Maximum | 1.00
Default | 0.20 | Units | s
Type | 8 Bit User Save | Update Rate | Background Write
Display Format | Standard | Decimal Places | 2
Coding | RW

See RFC Low Speed Mode (05.064).

Parameter | 05.064 RFC Low Speed Mode
--- | ---
Short description | Defines the low speed mode of the drive when position feedback is not being used
Mode | RFC‑S
Minimum | -1 | Maximum | 5
Default | 2 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text | Description
-1 | Non-salient | Starting mode for non-salient PM motors with limited load.
0 | Injection | High frequency injection mode
1 | Current | Current vector mode with initial test to determine the rotor position
2 | Current | Current vector mode with initial test to determine the rotor position
3 | Current No Test | Current vector mode without initial test to determine the rotor position
4 | Current Step | Current vector mode with no test and step changes in current between low/high speed modes
5 | Current Only | Current vector mode always active

If sensorless mode is being used and is active (i.e. Sensorless Mode Active (03.078) = 1) and the motor is operating at low speed then a low speed algorithm must be used to control the motor. The change between the low speed and normal operation algorithms is related to the drive output frequency. An upper threshold is provided for the change from low speed to normal operation, and a lower threshold is provided for the change back from normal to low speed operation as given in the table below. These values are a percentage of Rated Speed (05.008). If high saliency control is being used ( Active Saliency Torque Mode (05.066) = 2) then the lower threshold is always 15% and the upper threshold is 20%.

Switching Frequency (05.037) | Lower Threshold | Upper Threshold
2kHz | 5% | 10%
3kHz | 5% | 10%
4kHz | 5% | 10%
6kHz | 10% | 15%
8kHz | 10% | 15%
12kHz | 15% | 20%
16kHz | 15% | 20%

RFC Low Speed Mode (05.064) is used to select the algorithm to be used as described below. The following should be noted:

1. Non-salient and current modes should not be used for motors with high saliency.
2. Torque control can be used with the "Injection" starting method in the same way as with position feedback. However if torque control is to be used in an application where the other starting methods are used then the following should be considered: Torque control should not be enabled until the low speed algorithm is no longer active and the motor speed must not drop to a level where the low speed mode will become active again while torque control is active. This means that the motor must be started in speed control and torque control should only be selected when the speed is high enough. To stop the motor the drive can simply be disabled or the run command should be removed for the drive to stop the motor. Removing the run causes the drive to switch from torque control to speed control, and so the motor speed can be reduced back down though the range where the low speed algorithm is active.

-1: Non-salient
The rotational frequency of the current vector is controlled by the speed reference. Adjustment is provided to lock the current vector to the motor speed to minimise the d-axis voltage. For this system to operate correctly the motor should not have a high level of saliency and some d-axis current must be applied to the motor. Setting Low Speed Sensorless Mode Current (05.071) to 20% should be suitable.

0: Injection
A high frequency signal is injected into the motor to detect the motor flux axis. For this to operate correctly the motor must remain salient while the low speed mode is active. The no-load inductance parameters are checked by the drive on enable and if the motor is not sufficiently salient then a Inductance trip is initiated. See the details of this trip for the inductances required. Generally the q axis inductance falls as the q axis current is increased, i.e. the motor is loaded. While low speed operation is active the drive will apply a current limit defined by Low Speed Sensorless Mode Current (05.071) to prevent the q axis inductance from falling to a level that would cause the motor to become non-salient. It will be necessary to limit the bandwidth of the speed controller to a level of 10Hz or less for stable operation particularly at low speeds. Provided these conditions are met this method can be used in the same way as control with position feedback, but the control performance is limited.

1 or 2: Current
This method, which applies a rotating current vector at the frequency defined by the speed reference, can be used with any motor with no saliency or moderate saliency. It should only be used with motors where more of the torque is produced in conjunction with the magnet flux rather than from saliency torque. This mode does not provide the same level of control at low speed as injection mode, but it can be used with a motor that is not salient. The following should be considered:

1. Only speed control can be used when low speed mode operation is active.
2. A current specified by Low Speed Sensorless Mode Current (05.071) is applied when low speed mode is active. This current should be sufficient to start the motor with the highest expected load. If the motor has some saliency with no-load applied, and a suitable saturation characteristic, the drive can detect the rotor position and apply the current at the correct angle to avoid starting transient. If the motor is non-salient as defined by the conditions for Inductance trip then the drive will not attempt to detect the rotor position and the current will be applied at an arbitrary angle. This could cause a starting transient if the level of current applied is high, and so Low Speed Sensorless Mode Current (05.071) should not be set to a higher level than necessary. To minimise the movement as a result of applying the current, it is increased over the period defined by Sensorless Mode Current Ramp (05.063) in the form of a squared characteristic (i.e. it is increased with a low rate of change at the beginning and the rate of change is gradually increased).
3. It is not possible to measure the motor inertia using auto-tuning with Auto-tune (05.012) = 4.
4. As the level of current when low speed mode is active is not dependent on the applied load, but is as defined by Low Speed Sensorless Mode Current (05.071), and so the motor may become too hot if low speed mode is active for a prolonged period of time.
5. Generally Low Speed Sensorless Mode Current (05.071) should be set to a level higher than the expected maximum load, and can be set to a much higher level than the load if the saliency and saturation characteristic allow the position of the rotor to be detected on starting. However, Low Speed Sensorless Mode Current (05.071) should be matched more closely to the expected load under the following conditions: the load inertia is high compared to the motor inertia, or there is very little damping/loss in the load system, or where the q axis inductance of the motor changes significantly with load.

3: Current no test
The "Current" method is used, but no attempt is made to determine the position of the rotor before applying the current. This can be selected for example, if the motor does not have a suitable saturation characteristic to allow the rotor position to be determined during starting, or if faster starting is required. The initial current vector angle will be at an arbitrary position with respect to the actual rotor position. As the vector sweeps round it must make the rotor start to rotate. If the ramp rate is too high the rotor may not keep up with the current vector and the motor may not start. If this is the case then the ramp rate should be reduced and/or the current used to start the motor should be increased.

4: Current step
The current starting modes normally provide a smooth transition between the low speed current mode and normal running at higher speeds. If the drive accelerates very rapidly and only spends short periods of time in each mode the transition smoothing can malfunction. "Current step" mode is similar to "Current no test" mode except that the transition smoothing is disabled. It is not advisable to use this mode unless it is necessary as torque transients will occur when changing between low speed and normal running operation.

5: Current only
The "Current" method is used, but no attempt is made to determine the position of the rotor before applying the current. The system remains in this starting mode at all speeds and does not change to the normal operating algorithms. This provides a very basic open-loop control method, that is not recommended for most applications. Flux weakening is not possible, and so this method will not operate correctly when the motor voltage approaches the maximum voltage available from the drive.

The current applied to the motor is always the level defined by Low Speed Sensorless Mode Current (05.071) and the frequency is defined by the frequency reference. The following should be noted:

1. It is possible that the motor may become unstable especially on light load.
2. The current in the motor will always be at the level defined by Low Speed Sensorless Mode Current (05.071) whatever the load. Care should be taken not to overheat the motor.
3. The speed feedback provided is derived from the reference, and so it does not necessarily represent the actual speed of the motor.

Parameter | 05.065 Saliency Torque Control Select
--- | ---
Short description | Set the required saliency torque control mode
Mode | RFC‑S
Minimum | 0 | Maximum | 3
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
0 | Disabled
1 | Low
2 | High
3 | Auto

Most permanent magnet motors include some saliency due to saturation and physical construction. Torque is produced by interaction between the magnet flux and the stator current, but any saliency can be exploited to produce additional torque, which can increase the torque per amp produced by the motor. Synchronous reluctance motors have no magnets and rely on saliency to produce torque. This parameter combined with Ke for the active motor (Volts Per 1000rpm (05.033) or M2 Volts Per 1000rpm (21.030)) is used to select the operating mode. The actual mode selected is shown in Active Saliency Torque Mode (05.066).

Saliency Torque Control Select (05.065) | Mode selection method | Active Saliency Torque Mode (05.066)
0 or Rated Torque Angle (05.089) = 0 | No saliency torque is produced and all the torque is derived from the magnet flux. | Disabled
1 (Low) | Saliency torque is produced and the control algorithm is suitable for a low saliency permanent magnet motor is selected. | Low
2 (High) | Saliency torque is produced and the control algorithm is suitable for a high saliency permanent magnet motor is selected. | High
3 (Auto) | This is the recommended setting. The control algorithm is automatically selected based on Rated Torque Angle (05.089) and Volts Per 1000rpm (05.033) (or M2 Volts Per 1000rpm (21.030)) as described below. | Defined by automatic selection

If the auto setting is used the mode is automatically selected (and displayed in Active Saliency Torque Mode (05.066)) as follows:

1. If Rated Torque Angle (05.089) = 0 saliency torque is not produced. This mode is only suitable for low saliency PM motors.
2. If Rated Torque Angle (05.089) ≤ 30o and Volts Per 1000rpm (05.033) (or M2 Volts Per 1000rpm (21.030)) is non-zero saliency torque is produced and the control algorithm for low saliency PM motors is selected.
3. If Rated Torque Angle (05.089) > 30o and Volts Per 1000rpm (05.033) (or M2 Volts Per 1000rpm (21.030)) is non-zero saliency torque is produced and the control algorithm for high saliency PM motors is selected.
4. If Rated Torque Angle (05.089) > 30o and Volts Per 1000rpm (05.033) (or M2 Volts Per 1000rpm (21.030)) is zero then the control algorithm for synchronous reluctance motors is selected. This control algorithm cannot be used in sensorless mode.

Parameter | 05.066 Active Saliency Torque Mode
--- | ---
Short description | Active Saliency Torque Mode
Mode | RFC‑S
Minimum | 0 | Maximum | 3
Default |  | Units |
Type | 8 Bit Volatile | Update Rate | Background Write
Display Format | Standard | Decimal Places | 0
Coding | RO, TE, ND, NC, PT

Value | Text
0 | Disabled
1 | Low
2 | High
3 | Sync Reluctance

Active Saliency Torque Mode (05.066) shows which saliency torque control mode is active. See Saliency Torque Control Select (05.065) for more details.

Parameter | 05.067 Over-current Trip Level as Percentage Kc
--- | ---
Short description | Over-current trip level as a percentage of Kc
Mode | RFC‑S
Minimum | 0 | Maximum | 100
Default | 0 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read When Drive Not Active
Display Format | Standard | Decimal Places | 0
Coding | RW, BU

The drive provides an over-current trip to disable the inverter quickly if the instantaneous current from the drive exceeds a specific level. This trip is provided to protect the drive in case a short circuit is applied to the outputs, but it also prevents the current into the motor from exceeding a specific maximum level. If Over-current Trip Level as Percentage Kc (05.067) and Over-current Trip Level as Percentage of Rated Current (05.069) are left at their default values of zero then the default over-current trip level is used, which is provided to protect the drive, and is set to the maximum possible safe level of current. The current values shown in the Current Ratings table provided with this parameter reference guide (including the over-current trip level) are in r.m.s. Amps as this is more convenient because motor ratings etc. are also given as r.m.s. Amps. The over-current trip occurs when the instantaneous current exceeds the trip level, and so if the drive is producing a sinusoidal output current the actual trip detector threshold is the r.m.s. current x √2. Therefore, if the over-current trip level is set to trip the drive if the r.m.s. current exceeds Full Scale Current Kc (11.061) it would be set to Full Scale Current Kc (11.061) x √2. Particularly for smaller drive sizes, the over-current trip levels in the Current Ratings table are higher than this level to allow a margin for cable charging currents. Actual Over-current Trip Level (05.068) gives the actual over-current level being used by the drive as a percentage of Full Scale Current Kc (11.061), therefore the actual instantaneous over-current trip threshold is given by

Trip threshold (instantaneous Amps) = Full Scale Current Kc (11.061) x √2 x Actual Over-current Trip Level (05.068) / 100%

Particularly for smaller drive sizes, Actual Over-current Trip Level (05.068) may be higher than expected from the value given in the Current Ratings table because the parameter is showing the maximum instantaneous current that could occur before a trip is initiated. The current feedback hardware configuration in smaller drive sizes is such that the current in one of the drive output phases may exceed the level in the Current Ratings table before the trip occurs. Unless there is a good reason to limit the peak current to less than the default over-current trip level then these parameters should be left at their default values. However, permanent magnet motors are demagnetised immediately if the instantaneous motor current exceeds their demagnetisation level. If the trip threshold given above is higher than this level the over-current trip level will need to be reduced.

If Over-current Trip Level as Percentage of Rated Current (05.069) is set to a non-zero value it defines the over-current trip level as a percentage of the rated current (where the rated current is defined by Rated Current (05.007) or M2 Rated Current (21.007)). If Over-current Trip Level as Percentage of Rated Current (05.069) is non-zero then Over-current Trip Level as Percentage Kc (05.067) has no effect. The actual setting of the over-current trip in the hardware is relatively coarse, and so the trip level may be less than the selected setting. For this reason Actual Over-current Trip Level (05.068) shows the actual trip level as a percentage of rated current when Over-current Trip Level as Percentage of Rated Current (05.069) is used to define the trip level. As the over-current trip is normally reduced to protect a motor, using Over-current Trip Level as Percentage of Rated Current (05.069) to define this is the preferred method.

If required, the over-current trip level can be set as a percentage of Full Scale Current Kc (11.061) using Over-current Trip Level as Percentage Kc (05.067). Again due to the coarse setting in the drive hardware the actual over-current trip level may be less than the required level, and so Actual Over-current Trip Level (05.068) shows the actual trip level as a percentage of Full Scale Current Kc (11.061) when Over-current Trip Level as Percentage Kc (05.067) is used to define this. Either a value of zero should be used, so that the default level is applied (assuming Over-current Trip Level as Percentage of Rated Current (05.069) = 0) or a value from 10% to 100% should be used to define the level as a percentage of Kc. (Note there are settings from 1 to 9 which are only provided for legacy reasons and should not normally be used where the percentage is given by (Over-current Trip Level as Percentage Kc (05.067) + 1) x 10%.)

It should be noted that if the over-current trip level is reduced, it may be necessary to reduce the current limits from their default levels so that the maximum controllable current in the drive does not exceed the over-current trip level during normal operation, or else spurious trips will be produced.

Parameter | 05.068 Actual Over-current Trip Level
--- | ---
Short description | Actual Over-current Trip Level
Mode | RFC‑S
Minimum | 0 | Maximum | 500
Default |  | Units | %
Type | 16 Bit Volatile | Update Rate | Background Write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT, BU

See Over-current Trip Level as Percentage Kc (05.067).

Parameter | 05.069 Over-current Trip Level as Percentage of Rated Current
--- | ---
Short description | Over-current trip level as a percentage of rated current
Mode | RFC‑S
Minimum | 0 | Maximum | 1000
Default | 0 | Units | %
Type | 16 Bit User Save | Update Rate | Background Read When Drive Not Active
Display Format | Standard | Decimal Places | 0
Coding | RW

If this parameter has a non-zero value it overrides Over-current Trip Level as Percentage Kc (05.067) and the over-current trip level is calculated as a percentage of the motor rated current. See Over-current Trip Level as Percentage Kc (05.067) for more details. For some drive derivatives the default for Over-current Trip Level as Percentage of Rated Current (05.069) is non-zero. If this is the case, the lower level has been provided to protect motors where the demagnetisation level is relatively low. Before increasing this parameter the maximum allowed motor current MUST be checked to ensure that the over-current trip level is not above this level or else the motor may be PERMANENTLY DAMAGED.

Parameter | 05.070 Inverted Saturation Characteristic
--- | ---
Short description | Set to 1 if the motor has an inverted saturation characteristic
Mode | RFC‑S
Minimum | 0 | Maximum | 1
Default | 0 | Units |
Type | 1 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

The change of motor inductance with flux producing current is used to determine the flux direction in a permanent magnet motor. To do this the drive must know what type of saturation characteristic the motor has. Normally an increase in flux producing current reduces Ld because the motor becomes more saturated. For some motors increasing the flux producing current can modify the flux path and Ld increases with increased flux producing current. For normal motors Inverted Saturation Characteristic (05.070) should be left at its default value of zero, however, for motors with an apparent inverse saturation characteristic Inverted Saturation Characteristic (05.070) should be set to one. Inverted Saturation Characteristic (05.070) has an effect on the following:

Function | Details
Stationary auto-tune with position feedback | The saturation characteristic is used when the drive determines the angle between the position feedback and the motor flux Position Feedback Phase Angle (03.025). If the saturation characteristic is incorrect there will be an error of 180o in the result.
Measurement of the position feedback phase angle during starting with position feedback | If Minimal Movement Phasing Test Angle (05.016) is set to zero then inductance measurement is used to location the motor flux on starting. If Inverted Saturation Characteristic (05.070) is incorrect then there will be a 180o error in the value of Position Feedback Phase Angle (03.025).
Starting in sensorless mode using injection starting | If RFC Low Speed Mode (05.064) = 0 (Injection) the saturation characteristic is used to correctly align the system with the motor flux. If this is incorrect the operation when starting will be very unstable and the motor may operate in the wrong direction.

This parameter only applies to permanent magnet motors and not synchronous reluctance motors.

Parameter | 05.071 Low Speed Sensorless Mode Current
--- | ---
Short description | Current reference applied in low speed current mode or maximum current limit for low speed injection mode
Mode | RFC‑S
Minimum | 0.0 | Maximum | 1000.0
Default | 100.0 | Units | %
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

See RFC Low Speed Mode (05.064).

Parameter | 05.072 No-load Lq
--- | ---
Short description | q axis inductance with no motor current
Mode | RFC‑S
Minimum | 0.000 | Maximum | 500.000
Default | 0.000 | Units | mH
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 3
Coding | RW

The torque (or quadrature) axis inductance (Lq) is used for a number of functions in the drive as shown in the table below.

Function | Details
High performance current control | If high performance current control is selected (Current Controller Mode (04.030) =1) No-load Lq is used by the controller in q axis.
Low speed operation with sensorless control | If injection mode is used (RFC Low Speed Mode (05.064) = 0) for low speed operation No-load Lq defines the gain of the system.
Control above low speeds with sensorless control | No-load Lq is used in the system that actively calculates the value of Lq with changing motor currents which is used to calculate the rotor position. See below this table.
Rated torque angle | If the drive defines Rated Torque Angle (05.089) , because it has not been defined (i.e. User Defined Rated Torque Angle (05.087) = 0) then the dynamically calculated value of Lq (see below this table) is used in the calculation.
Motor torque limit | No-load Lq (not the dynamic value described below this table) is used in calculating the torque limit for high saliency motors.

The value of Lq is usually affected by the level of d and q axis motor current, and so the drive can estimate Lq dynamically as the current levels change. The following parameters are also used in the system that calculates the value of Lq with different levels of motor current:

q Axis Current For Inductances (05.075)
Lq At The Defined Iq Current (05.078)
d Axis Current For Inductances (05.082)
Lq At The Defined Id Current (05.084)

Lq is estimated using a flat 3D surface (plane) based on the level of Id and Iq. Id is always assumed to be negative. The effect of Iq is the same whether it is positive or negative, and so |Iq| is used. The plane is defined by

Lq = A + B x Id + C x |Iq|

where

ΔId = d Axis Current For Inductances (05.082) x Rated Current (05.007) / 100%
ΔIq = q Axis Current For Inductances (05.075) x Rated Current (05.007) / 100%

(or M2 Rated Current (21.007) is used as rated current if Select Motor 2 Parameters (11.045)=1 to select Motor Map 2).

A = No-load Lq (05.072)
B = (Lq At The Defined Id Current (05.084) - No-load Lq (05.072)) / ΔId
C = (Lq At The Defined Iq Current (05.078) - No-load Lq (05.072)) / ΔIq

The default current levels for Lq At The Defined Id Current (05.084) and Lq At The Defined Iq Current (05.078) are -100% (of rated current) and 100% (of rated current) respectively. This ensures that the operating point for the motor (i.e. at rated current) is always on the flat surface within the range of the three points that define it (No-load Lq (05.072), (Lq At The Defined Id Current (05.084) and (Lq At The Defined Iq Current (05.078)). The plane extends beyond the range covered, but the estimated value of Lq is never allowed to go below zero.

No-load Lq (05.072) should be set to the correct value or measured using auto-tuning. For some motors it is not necessary to set Lq At The Defined Id Current (05.084) or Lq At The Defined Iq Current (05.078) because of the behaviour of the drive with specific values as described in the table below.

Parameter value for specific behaviour | Effect | Suitable for...
Lq At The Defined Iq Current (05.078) = 0.000mH Default = 0.000mH | C = -0.2 x No-load Lq (05.072) / ΔIq | Low saliency motors where the change in Lq is less than or equal to 20% of the no-load value under rated conditions.
q Axis Current For Inductances (05.075) = 0% Default = 100% | C = 0 | Low saliency motors where the change in Lq is minimal.
Lq At The Defined Id Current (05.084) = 0.000mH Default = 0.000mH | B = 0 | All motors where the change in Lq with Id is relatively small.
d Axis Current For Inductances (05.082) = 0% Default = -100% | B = 0 | All motors where the change in Lq with Id is relatively small.

Parameter | 05.075 q Axis Current For Inductances
--- | ---
Short description | q axis current level corresponding to the inductance values
Mode | RFC‑S
Minimum | 0 | Maximum | 200
Default | 100 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW, BU

See No-load Lq (05.072).

Parameter | 05.077 Phase Offset At Defined Iq Current
--- | ---
Short description | Defines the change in electrical angle between the point of minimum inductance around the motor as load is applied
Mode | RFC‑S
Minimum | -90.0 | Maximum | 90.0
Default | 0.0 | Units | °
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

Phase Offset At Defined Iq Current (05.077) defines the offset of the point of minimum inductance as an electrical angle from the point with no current in the motor to the point with a level of Iq equivalent to q Axis Current For Inductances (05.075). When the value is left at its default value of zero no compensation for phase offset with changes in Iq are made. Phase Offset At Defined Iq Current (05.077) is used for low speed RFC sensorless control using injection mode. A positive value advances the point of minimum inductance with positive Iq. See RFC Low Speed Mode (05.064). For most motors, a value of zero is acceptable.

Parameter | 05.078 Lq At The Defined Iq Current
--- | ---
Short description | q axis inductance at the defined Iq current for the inductance values
Mode | RFC‑S
Minimum | 0.000 | Maximum | 500.000
Default | 0.000 | Units | mH
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 3
Coding | RW

See No-load Lq (05.072).

Parameter | 05.082 d Axis Current For Inductances
--- | ---
Short description | d axis current level corresponding to the inductance values
Mode | RFC‑S
Minimum | -200 | Maximum | 0
Default | -100 | Units | %
Type | 16 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

See No-load Lq (05.072).

Parameter | 05.084 Lq At The Defined Id Current
--- | ---
Short description | q axis inductance at the defined Id current for the inductance values
Mode | RFC‑S
Minimum | 0.000 | Maximum | 500.000
Default | 0.000 | Units | mH
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 3
Coding | RW

See No-load Lq (05.072).

Parameter | 05.087 User Defined Rated Torque Angle
--- | ---
Short description | User defined rated torque angle which will override the drive auto-calculated value.
Mode | RFC‑S
Minimum | 0 | Maximum | 90
Default | 0 | Units | °
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

Rated Torque Angle (05.089) defines the amount of torque and flux producing current required to give maximum torque from the motor with rated current (i.e. Rated Current (05.007)) including any torque produced from saliency. The torque angle is the angle between the q axis of the motor and the current vector required to produce the torque. This is also referred to as the current angle or phase advance angle. If Saliency Torque Control Select (05.065) ≥ 1 the drive will try and exploit the saliency torque of the motor by applying some negative d axis current. If User Defined Rated Torque Angle (05.087) is changed from its default value of zero and Saliency Torque Control Select (05.065) ≥ 1, the value entered in User Defined Rated Torque Angle (05.087) is written directly to Rated Torque Angle (05.089) and defines the angle used for the applied current from the q axis. As the torque angle is increased the amount of negative d axis current increases. This angle should be set to the level to give maximum torque per Amp with rated current in the motor.

It is possible for the drive to automatically calculate the rated torque angle from motor set-up parameters and those measured during autotuning. The drive will calculate and set up Rated Torque Angle (05.089) if Saliency Torque Control Select (05.065) ≥ 1 and User Defined Rated Torque Angle (05.087) = 0. The following parameters are used in the calculation for a permanent magnet motor:

Rated Current (05.007)
Ld (05.024)
No-load Lq (05.072)
Volts Per 1000rpm (05.033) (1)
q Axis Current For Inductances (05.075)
Lq At The Defined Iq Current (05.078) (2)
d Axis Current For Inductances (05.082)
Lq At The Defined Id Current (05.084) (2)

(1) This must be non-zero for a permanent magnet motor.
(2) The value of Lq used in the calculation is the value estimated using the same algorithm when the drive is running. See No-load Lq (05.072) for the effect of leaving these parameters at their default values.

If Ke is set to zero (i.e., for a synchronous reluctance motor) the automatic value written to Rated Torque Angle (05.089) is 45o.

Parameter | 05.088 Estimated Lq
--- | ---
Short description | Estimated value of Lq including the effects of Id and Iq
Mode | RFC‑S
Minimum | 0.000 | Maximum | 500.000
Default |  | Units | mH
Type | 32 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 3
Coding | RO, FI, ND, NC, PT

Estimated Lq (05.088) shows the calculated value of Lq. See No-load Lq (05.072).

Parameter | 05.089 Rated Torque Angle
--- | ---
Short description | Rated Torque Angle
Mode | RFC‑S
Minimum | 0 | Maximum | 90
Default |  | Units | °
Type | 8 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, ND, NC, PT

See User Defined Rated Torque Angle (05.087).

Parameter | 05.090 Maximum Torque Angle
--- | ---
Short description | Defines the maximum torque angle for a synchronous reluctance motor.
Mode | RFC‑S
Minimum | 45 | Maximum | 90
Default | 80 | Units | °
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

When a synchronous reluctance motor operates at the maximum voltage that can be supplied by the drive, including the effect of voltage headroom defined by Voltage Headroom (05.041), or the level defined by Rated Voltage (05.009) whichever is lowest there is a limit on the maximum torque that can be produced by the motor. Once the maximum voltage has been reached using the rated torque angle, the angle is increased as this allows additional torque to be produced. The angle is increased up to the angle defined by Maximum Torque Angle (05.090). This angle must be defined to prevent the control system from passing the point of maximum possible torque or the system will become unstable. In theory the maximum torque angle is defined as 90o - atan(Ld/Lq), however it is difficult to calculate this as the inductances vary with current. The default value is likely to be suitable but can be reduced to prevent instability or increased to allow more torque to be produced when the motor voltage is at the maximum level.