# Menu 5 − Motor Control

Mode: RFC‑A

Parameter | 05.001 Output Frequency
--- | ---
Short description | Frequency applied to the motor
Mode | RFC‑A
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‑A
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‑A
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‑A
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 | 05.006 Rated Frequency
--- | ---
Short description | Set to the rated frequency of the motor
Mode | RFC‑A
Minimum | 0.0 | Maximum | 550.0
Default | See exceptions below | Units | Hz
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

Region | Default Value
50Hz | 50.0
60Hz | 60.0

Rated Frequency (05.006), Rated Speed (05.008) and Number Of Motor Poles (05.011) are used to calculate the rated slip of the motor which is used by the motor control algorithm when the drive is supplying an induction motor. An incorrect estimate of rated slip has the following effects:

1. Reduced efficiency
2. Reduction of maximum torque available from the motor
3. Reduced transient performance
4. Inaccurate control of absolute torque in torque control modes
5. The drive will produce rated flux in the motor in the shortest possible time when it is enabled. Incorrect parameter values will affect the flux build-up time.

The rated speed on the motor nameplate is normally the value for a hot motor, however, some adjustment may be required when the drive is commissioned if this is inaccurate. Either a fixed value can be entered for Rated Speed (05.008) or the optimisation system within the drive may be used to automatically adjust the Rated Speed (05.008). See Rated Speed Optimisation Select (05.016). It should be noted that the optimisation system does not operate when sensorless RFC-A mode is used (i.e. Sensorless Mode Active (03.078) = 1).

Parameter | 05.007 Rated Current
--- | ---
Short description | Set to the rated current of the motor
Mode | RFC‑A
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.
Motor control | Used in the motor control algorithm.
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‑A
Minimum | 0.00 | Maximum | 33000.00
Default | See exceptions below | Units | rpm
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 2
Coding | RW

Region | Default Value
50Hz | 1500.00
60Hz | 1800.00

See Rated Frequency (05.006).

Parameter | 05.009 Rated Voltage
--- | ---
Short description | Set to the rated voltage of the motor
Mode | RFC‑A
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 Rated Voltage (05.009) is the maximum continuous voltage that is applied to the motor. Normally this should be set to the motor nameplate value. If the drive is supplied through its own diode rectifier the maximum possible output voltage is just below the supply voltage level, and so the output voltage will not reach Rated Voltage (05.009) if this is equal to or above the supply voltage. If high transient performance is required at higher speeds then Rated Voltage (05.009) should be set to 95% of the minimum d.c. link voltage divided by √2 to allow some headroom for the drive to control the motor current. If the drive is fed through its own diode rectifier the minimum d.c. link voltage is approximately supply voltage x √2.

In some cases it may be necessary to set the Rated Voltage (05.009) to a value other than the motor nameplate value. If this is the case the Rated Frequency (05.006) and Rated Speed (05.008) should be set up as follows:

K = Rated Voltage (05.009) / motor rated voltage

Rated Frequency (05.006) = motor rated frequency x K

Rated Speed (05.008) = motor rated speed + [(K - 1) x motor rated frequency x 60 / (number of motor poles / 2)]

The Rated Voltage (05.009), Rated Frequency (05.006) and Number Of Motor Poles (05.011) are used during the auto-tuning process to determine the flux level required in the motor for normal operation. Therefore if the Rated Voltage (05.009) is set to a value other than the nameplate value and the above adjustment is not applied the motor may be under or over-fluxed

Parameter | 05.010 Rated Power Factor
--- | ---
Short description | Set to the rated power factor of the motor. This value can be measured by the drive during a rotating autotune.
Mode | RFC‑A
Minimum | 0.000 | Maximum | 1.000
Default | Default Power Factor | Units |
Type | 16 Bit User Save | Update Rate | Background read/write
Display Format | Standard | Decimal Places | 3
Coding | RW

Rated Power Factor (05.010) is the true power factor of the motor under rated conditions, i.e. the cosine of the angle between the motor voltage and current. If Stator Inductance (05.025) is set to a non-zero value then the stator inductance is used to calculate the rated magnetising current for the motor and the rated power factor can be calculated by the drive. Therefore if Stator Inductance (05.025) is non-zero Rated Power Factor (05.010) is continuously set to the calculated value of rated power factor by the drive. If Stator Inductance (05.025) is set to zero then Rated Power Factor (05.010) is used to estimate the rated magnetising current which is an approximation and not as accurate. Stator Inductance (05.025) can be measured by the drive during auto-tuning and this is the preferred option, however, if it is not possible to obtain the value for Stator Inductance (05.025) then Rated Power Factor (05.010) should be set to the motor nameplate value.

Parameter | 05.011 Number Of Motor Poles
--- | ---
Short description | Set to the number of poles of the motor
Mode | RFC‑A
Minimum | 0 | Maximum | 240
Default | 0 | 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 are calculated automatically as given below.

> Pole pairs = 60 x Rated Frequency (05.006) / Rated Speed (05.008) rounded down to the nearest integer.

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‑A
Minimum | 0 | Maximum | 4
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 | Basic
2 | Improved
3 | Inertia 1
4 | Inertia 2

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

1. 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.
2. 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.
3. 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.
4. 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 reapplying 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.
5. 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.
6. 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-A 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 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 Frequency (05.006) | Basic control | User set-up
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
Rated Power Factor (05.010) | Basic control | 2
Number Of Motor Poles (05.011) | Basic control | User set-up
Stator Resistance (05.017) | Basic control | 1, 2
Transient Inductance (05.024) | Basic control | 1, 2
Stator Inductance (05.025) | Improved performance | 2
Saturation Breakpoint 1 (05.029) | Improved performance with flux weakening | 2
Saturation Breakpoint 3 (05.030) | Improved performance with flux weakening | 2
Maximum Deadtime Compensation (05.059) | Basic control | 1, 2
Current At Maximum Deadtime Compensation (05.060) | Basic control | 1, 2
Saturation Breakpoint 2 (05.062) | Improved performance with flux weakening | 2
Saturation Breakpoint 4 (05.063) | Improved performance with flux weakening | 2
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
Current Controller Kp Gain (04.013) | Basic control | 1, 2
Current Controller Ki Gain (04.014) | Basic control | 1, 2
No-load Core Loss (04.045) | *Torque feedback | 2
Rated Core Loss (04.046) | *Torque feedback | User set-up

*Torque feedback is provided in Percentage Torque (04.026). The estimated value can be improved by setting up the No-load Core Loss (04.045) and Rated Core Loss (04.046) for the motor. It should be noted that the core loss characteristic for a motor is complex and depends to some extent on the switching frequency, but the drive can include an approximation to the core losses based on these two parameters. The value for the no-load core losses measured by the auto-tuning is likely to be higher than the actual value, but can be used to significantly reduce the difference that will be seen in the estimate torque between motoring and regenerating operation. If more accurate core loss compensation is required No-load Core Loss (04.045) and Rated Core Loss (04.046) must be set up based on testing the motor using a torque transducer.

1: Basic
This test measures the basic control parameters without moving the motor.

1. A stationary test is performed to measure Stator Resistance (05.017), Transient Inductance (05.024), Maximum Deadtime Compensation (05.059) and Current At Maximum Deadtime Compensation (05.060). If Enable Stator Compensation (05.049) = 1 then Stator Base Temperature (05.048) is made equal to Stator Temperature (05.046).
2. Stator Resistance (05.017) and Transient Inductance (05.024) are used to set up Current Controller Kp Gain (04.013) and Current Controller Ki Gain (04.014). This is only performed once during the test, and so the user can make further adjustments to the current controller gains if required.

2: Improved
This test measures the parameters for improved performance by rotating the motor.

1. Auto-tune 1 test is performed.
2. A rotating test is performed in which the motor is accelerated with the currently selected ramps up to a frequency of Rated Frequency (05.006) x 2/3, and the frequency is maintained at that level for up to 40 seconds. Stator Inductance (05.025) is measured and this value is used in conjunction with other motor parameters to calculate Rated Power Factor (05.010). Saturation Breakpoint 1 (05.029), Saturation Breakpoint 3 (05.030), Saturation Breakpoint 2 (05.062) and Saturation Breakpoint 4 (05.063) are measured. The no-load motor core losses are measured and written to No-load Core Loss (04.045). It is not possible to measure the rated load motor core losses, and so Rated Core Loss (04.046) is set to zero. The motor should be unloaded for this test.

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 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.

1. A rotating test is performed in which the motor is accelerated with the currently selected ramps up to the currently selected speed reference, and this speed is maintained for the duration of the test. The Motor And Load Inertia (03.018) and Inertia Times 1000 (04.033) are set up.

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 will not give such accurate results as test 3 if the motor rated speed is not set to the correct value for the motor. Also 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 reached 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.

1. The motor is accelerated in the required direction up to 3/4 of the maximum speed reference and then decelerated to zero speed.
2. The test is repeated with progressively higher torques until the required speed is reached.
3. Motor And Load Inertia (03.018) and Inertia Times 1000 (04.033) are set up.

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 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 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).

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

Parameter | 05.013 Flux Optimisation Select
--- | ---
Short description | Set to 1 to enable Flux Optimisation
Mode | RFC‑A
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 Flux Optimisation Select (05.013) = 0 the rated level of flux is used in the motor when flux weakening is not active. If Flux Optimisation Select (05.013) = 1 the flux is reduced so that the Id, Magnetising Current (04.017) is approximately equal to the Iq, Torque Producing Current (04.002) to optimise copper losses and reduce iron losses in the motor under low load conditions. The flux can be reduced from the rated level down to half the rated level. This feature is not available with sensorless mode (i.e. when Sensorless Mode Active (03.078) = 1).

Parameter | 05.015 Low Frequency Voltage Boost
--- | ---
Short description | Defines the level of low voltage boost when performing auto-tune test 2
Mode | RFC‑A
Minimum | 0.0 | Maximum | 25.0
Default | Default Voltage Boost / 10 | Units | %
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW, BU

The default value for this parameter depends on the frame size of the drive as follows:

- 3.0% up to frame size 06 drives,
- 2.0% for frame size 07 and frame size 08 drives
- 1.0% for larger sizes

During auto-tune test 2 the drive uses the Open-loop mode control strategy with fixed voltage boost. Low Frequency Voltage Boost (05.015) is used to define the level of low voltage boost used during the test. See Open-loop Control Mode (05.014) in Open-loop mode for more details.

Parameter | 05.016 Rated Speed Optimisation Select
--- | ---
Short description | Rated Speed Optimisation Select
Mode | RFC‑A
Minimum | 0 | Maximum | 5
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 | Classic Slow
2 | Classic Fast
3 | Combined
4 | VARs Only
5 | Voltage Only

The Rated Frequency (05.006) and Rated Speed (05.008) are used to define the rated slip of the motor. The rated slip is used in sensorless mode (Sensorless Mode Active (03.078) = 1) to correct the motor speed with load. When this mode is active Rated Speed Optimisation Select (05.016) has no effect.

If sensorless mode is not active (Sensorless Mode Active (03.078) = 0) the rated slip is used in the motor control algorithm and an incorrect value of slip can have a significant effect on the motor performance. If Rated Speed Optimisation Select (05.016) = 0 then the adaptive control system is disabled. However, if Rated Speed Optimisation Select (05.016) is set to a non-zero value the drive can automatically adjust the Rated Speed (05.008) to give the correct value of rated slip. Rated Speed (05.008) is not saved at power-down, and so when the drive is powered-down and up again it will return to the last value saved by the user. The rate of convergence and the accuracy of the adaptive controller reduces at low output frequency and low load. The minimum frequency is defined as a percentage of Rated Frequency (05.006) by Rated Speed Optimisation Minimum Frequency (05.019). The minimum load is defined as a percentage of rated load by Rated Speed Optimisation Minimum Load (05.020). The adaptive controller is enabled when a motoring or regenerative load rises above Rated Speed Optimisation Minimum Load (05.020) + 5%, and is disabled again when it falls below Rated Speed Optimisation Minimum Load (05.020). For best optimisation results the correct values of Stator Resistance (05.017), Transient Inductance (05.024), Stator Inductance (05.025), Saturation Breakpoint 1 (05.029), Saturation Breakpoint 2 (05.062), Saturation Breakpoint 3 (05.030) and Saturation Breakpoint 4 (05.063) should be used.

A number of different adaptive control methods can be selected as follows:

Rated Speed Optimisation Select (05.016) | Adaptive Method
0 - Disabled | None
1 - Classic Slow | VARs at low speed and vsy at higher speeds with low adaptive gain
2 - Classic Fast | VARs at low speed and vsy at higher speeds with high adaptive gain
3 - Combined | VARs when flux weakening is not active, vsy when flux weakening is active with medium adaptive gain
4 - VARs | VARs with medium adaptive gain
5 - Vsy | vsy with medium adaptive gain

The classic methods normally operate correctly, but can diverge from the corrected rated speed especially with regenerative operation. These are provided for legacy applications. The "Combined" method is the preferred method as this is more robust against divergence. However the VARs method can be affected if the value of Transient Inductance (05.024) used by the drive is incorrect for the motor. It is possible to select the VARs or vsy methods alone if required. All except the "Classic Slow" adaptive method use high adaptive gain which gives faster convergence.

Parameter | 05.017 Stator Resistance
--- | ---
Short description | Defines the resistance of the motor stator
Mode | RFC‑A
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 Stator Resistance (05.017), Transient Inductance (05.024) and Stator Inductance (05.025) are derived from the star connected per phase equivalent circuit of an induction motor shown below.

The steady state parameters are converted to equivalent transient model parameters:

Rs = R1

Lm = Lm

Ls = L1 + Lm

Lr = L2 + Lm

σLs = Ls - (Lm2 / Lr)

The equivalent drive parameters are:

Stator Resistance (05.017) = Rs

Transient Inductance (05.024) = σLs

Stator Inductance (05.025) = Ls

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‑A
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 | 05.019 Rated Speed Optimisation Minimum Frequency
--- | ---
Short description | Rated Speed Optimisation Minimum Frequency
Mode | RFC‑A
Minimum | 0 | Maximum | 100
Default | 10 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Rated Speed Optimisation Select (05.016).

Parameter | 05.020 Rated Speed Optimisation Minimum Load
--- | ---
Short description | Rated Speed Optimisation Minimum Load
Mode | RFC‑A
Minimum | 0 | Maximum | 100
Default | 50 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

See Rated Speed Optimisation Select (05.016).

Parameter | 05.021 Mechanical Load Test Level
--- | ---
Short description | Mechanical Load Test Level
Mode | RFC‑A
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 | 05.024 Transient Inductance
--- | ---
Short description | Defines the inductance of the transient components in the motor stator
Mode | RFC‑A
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 Stator Resistance (05.017).

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

Function | Details
Current controller proportional gain set-up | During auto-tuning the stator resistance is used in the calculation of the current controller proportional gain.
High performance current control | If high performance current control is selected (Current Controller Mode (04.030)) the transient inductance is used.
Voltage based torque limit | The system that prevent the motor from exceeding its voltage based torque limit used the transient inductance.
Sensorless mode control | If sensorless mode is selected the transient inductance is used in defining the flux axis of the motor.

Parameter | 05.025 Stator Inductance
--- | ---
Short description | Defines the inductance of the motor stator
Mode | RFC‑A
Minimum | 0.00 | Maximum | 5000.00
Default | 0.00 | Units | mH
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 2
Coding | RW

See Stator Resistance (05.017).

Stator Inductance (05.025) is used as described in the table below.

Function | Details
Rated current components | Along with the stator resistance and transient inductance, the stator inductance is used to calculate the flux producing and torque producing current components, and the power factor.
Voltage based torque limit | The system that prevent the motor from exceeding its voltage based torque limit used the transient inductance.
Voltage feed-forwards | Voltage feed-forwards is provided for the current controllers which improves performance and reduces transient when starting with position feedback.
Flux level | The stator inductance is used to set the correct flux level in the motor.

Parameter | 05.026 High Dynamic Performance Enable
--- | ---
Short description | Set to 1 to enable High Dynamic Performance
Mode | RFC‑A
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‑A
Minimum | -10.0 | Maximum | 10.0
Default | 1.0 | Units |
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

The output voltage is limited to the voltage limit defined either by the maximum possible drive output voltage or Rated Voltage (05.009) whichever is lowest by the outer voltage controller shown below. If the voltage limit is not active then the output of the voltage controller is clamped to give rated flux in the motor. An inner flux controller is provided to control the magnetising current which is limted by Magnetising Current Limit (04.049). Using an inner flux controller gives faster rate of rise of flux on enable because a magnetising current higher than rated magnetising current can be used to force the flux to increase. It also gives faster reduction of flux as the motor accelerates into flux weakening because negative flux producing current can be used to reduce the flux.

Default set-up
If Flux Control Gain (05.027) is set to the default value of 1.0 the system that controls the flux and motor voltage is automatically set up based on the motor parameters to give stable operation. The closed-loop transfer function of the flux controller approximates to a first order time constant of 25ms, and the closed-loop transfer function of the voltage controller approximates to a first order time constant of 50ms. The automatic set-up of the flux controller can result is very high gains if the motor has a very long rotor time constant (i.e. greater than 0.5s), and this can result in noise on the magnetising current. To avoid this the gain is limited, and so the response time of the flux and voltage controllers will reduce proportionally when the rotor time contant exceeds 0.5s. For example if the rotor time contant is 1s then the response time of the controllers will be doubled (i.e. flux control 50ms and voltage control 100ms).

Improved voltage control
The integral gain of the voltage controller is set to a conservative value to ensure the system is always stable. If Flux Control Gain (05.027) is changed from the default value of 1.0 in the range from 0.1 to 10.0 the integral gain of the voltage controller is multiplied by Flux Control Gain (05.027). This is most useful to increase the integral gain of the voltage controller, so that the motor voltage is more tightly controlled during fast acceleration into the flux weakening region. The only gain that is affected is the integral gain of the voltage controller and the maximum limit on the flux controller gains described in the default set-up still applies.

Reduced noise on the magnetising current
The maximum limit on the flux controller gains should prevent excessive noise on the magnetising current when the motor has a long rotor time constant. However, if Flux Control Gain (05.027) is reduced below -1.0 the time constants of the flux controller and voltage closed-loop transfer function are extended. For example a value of -2.0 will extend these to 50ms and 100ms respectively. It should be noted that if the motor has a long rotor time constant, smaller negative values may not have an effect because the maximum limits on the flux controller gain may already be extending the time constants.

The settings for Flux Control Gain (05.027) are summarised below.

Range | Effect
-10.0 to -1.0 | Equivalent time constants of the controllers are Default Time Constant x -Flux Control Gain (05.027).
-1.0 to 0.0 | Default set-up is used.
0.1 to 10.0 | Default set-up is used, except that the integral gain of the voltage controller is Default Integral Gain x Flux Control Gain (05.027).

In all cases the controller gains are limited with a rotor time constant that is longer than 0.5s.

Parameter | 05.028 Flux Compensation
--- | ---
Short description | Determines the method used for flux compensation
Mode | RFC‑A
Minimum | 0 | Maximum | 2
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

To maintain the system gain if speed control is being used, or to maintain the correct relationship between the torque reference and the actual torque, the conversion from Final Torque Reference (04.003) to Final Current Reference (04.004) normally includes the level of flux in the motor. If Flux Compensation (05.028) is left at its default value of 0, the drive uses an estimate of motor flux to perform the conversion. This is the preferred method of operation. There can be stability problems especially at very high speeds under some circumstances and Flux Compensation (05.028) can be used to change the method of compensation to overcome the issues. If Flux Compensation (05.028) = 1, then torque to torque producing current compensation is disabled altogether. This can be used for example, if Rated Speed (05.008) is set up incorrectly. If Flux Compensation (05.028) = 2, Final Current Reference (04.004) = Final Torque Reference (04.003) x Rated Frequency (05.006) / |Output Frequency (05.001)|. This is not as accurate as using the calculated flux, and does not boost the torque on starting as the flux is increased in the motor, but it reduces the likelihood of instability at high speeds and high levels of flux weakening.

Parameter | 05.029 Saturation Breakpoint 1
--- | ---
Short description | Defines Saturation Breakpoint 1 within the saturation characteristic
Mode | RFC‑A
Minimum | 0.0 | Maximum | 100.0
Default | 50.0 | Units | %
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

The relationship between the Id, Magnetising Current (04.017) and the motor flux is non-linear because of saturation. For accurate control of torque and good dynamic performance when flux weakening is active it is important that the control system can estimate the flux level from the Id, Magnetising Current (04.017). The saturation characteristic is provided with a set of breakpoints as shown below.

The default values for the breakpoints are Saturation Breakpoint 1 (05.029) = 50.0%, Saturation Breakpoint 2 (05.062) = 0.0%, Saturation Breakpoint 3 (05.030) = 75.0% and Saturation Breakpoint 4 (05.063) = 0.0%. For compatibility with Unidrive SP, Saturation Breakpoint 2 (05.062) and Saturation Breakpoint 4 (05.063) are ignored if they are left at their default values of 0.0%. Therefore the default values give a linear relationship between the Id, Magnetising Current (04.017) and the flux. The required values are not normally available from the motor manufacturer and should be obtained by auto-tuning.

Parameter | 05.030 Saturation Breakpoint 3
--- | ---
Short description | Defines Saturation Breakpoint 3 within the saturation characteristic
Mode | RFC‑A
Minimum | 0.0 | Maximum | 100.0
Default | 75.0 | Units | %
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

See Saturation Breakpoint 1 (05.029).

Parameter | 05.031 Voltage Controller Gain
--- | ---
Short description | Defines the proportional gain of the d.c. link voltage controller
Mode | RFC‑A
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 | Displays the calculated value of kt for the attached motor
Mode | RFC‑A
Minimum | 0.00 | Maximum | 500.00
Default |  | Units | Nm/A
Type | 16 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 2
Coding | RO, ND, NC, PT, BU

Torque Per Amp (05.032) is automatically calculated from the motor parameters assuming a motor efficiency of 90%.

Torque Per Amp (05.032) = Estimated rated shaft power / [(Rated Speed (05.008) x 2π / 60) x ITRated]

where

ITRated is the rated torque producing current

and

Estimated rated shaft power = √3 x Rated Voltage (05.009) x Rated Current (05.007) x Rated Power Factor (05.010) x 0.9

Torque Per Amp (05.032) is used in the automatic calculation of the speed controller gains. See Speed Controller Set-up Method (03.017).

Parameter | 05.034 Percentage Flux
--- | ---
Short description | Displays the flux level in the motor
Mode | RFC‑A
Minimum | 0.0 | Maximum | 150.0
Default |  | Units | %
Type | 16 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 1
Coding | RO, FI, ND, NC, PT

Percentage Flux (05.034) gives an indication of the flux level in the motor where a value of 100% is equivalent to the rated flux level for the motor.

Parameter | 05.035 Auto-switching Frequency Change
--- | ---
Short description | Defines auto-switching frequency control with thermal model
Mode | RFC‑A
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‑A
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‑A
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‑A
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‑A
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 | 05.040 Spin Start Boost
--- | ---
Short description | Defines the level of spin start boost used by the algorithm that detects the speed of a spinning motor
Mode | RFC‑A
Minimum | 0.0 | Maximum | 10.0
Default | 1.0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

Spin Start Boost (05.040) is used by the algorithm that detects the speed of a spinning motor when the drive is enabled and Catch A Spinning Motor (06.009) ≥ 1. This algorithm is not used if position feedback is being used, and so in these applications Spin Start Boost (05.040) has no effect. For most motors Spin Start Boost (05.040) does not need to be changed from the default value, but for some larger motors Spin Start Boost (05.040) may need to be increased. If Spin Start Boost (05.040) is too small the drive will detect zero speed whatever the speed of the motor, and if Spin Start Boost (05.040) is too large the motor may accelerate away from standstill when the drive is enabled.

Parameter | 05.041 Voltage Headroom
--- | ---
Short description | Voltage Headroom
Mode | RFC‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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‑A
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

The slip of an induction motor is proportional to the rotor resistance, and so as the motor becomes hotter the slip increases. Therefore the rated speed of a motor, which is used by the drive control algorithm, changes with rotor temperature. To avoid less than optimal control the rated speed value used by the drive should be modified with changing rotor temperature. Temperature compensated rated speed (05.057) shows the rated speed from the active motor that is being used by the drive control system. If Enable Rotor Compensation (05.056) = 0 and motor 1 is selected (i.e. Motor 2 Active (21.015) = 0) then Temperature compensated rated speed (05.057) is equal to Rated Speed (05.008). If Enable Rotor Compensation (05.056) = 1 then Temperature compensated rated speed (05.057) is calculated as follows:

Uncompensated Rated Slip = Synchronous Speed - Rated Speed (05.008) = (Rated Frequency (05.006) x 60 / Number Of Motor Poles (05.011)) - Rated Speed (05.008)

α = Rotor Temperature Coefficient (05.054) and this is the rotor winding temperature coefficient at 20oC as a proportion of the resistance per degree C.

Compensated Rated Slip = Uncompensated Rated Slip x [1 + (Rotor Temperature (05.053) - 20oC) x α] / [1 + (Rotor Base Temperature (05.055) - 20oC) x α]

Temperature compensated rated speed (05.057) = (Rated Frequency (05.006) x 60 / Number Of Motor Poles (05.011)) - Compensated Rated Slip

If sensorless mode is not being used (i.e. Sensorless Mode Active (03.078) = 0) then an adaptive system is provided to adjust the Rated Speed (05.008) value (see Rated Speed Optimisation Select (05.016)). The adaptive control system cannot operate at low speeds or light loads, and so the rated speed may be incorrect if the motor runs under these conditions for a long period of time. If adaptive control is selected (i.e.Rated Speed Optimisation Select (05.016) > 0) and Enable Rotor Compensation (05.056) = 1 then Rotor Base Temperature (05.055) is updated with Rotor Temperature (05.053) while the adaptive controller is active, and so the rotor compensation system has no effect. When the adaptive controller changes to the inactive state because of the speed and load conditions, the Rotor Base Temperature (05.055) is no longer updated and the difference between this and the Rotor Temperature (05.053) is used to adjust the Rated Speed (05.008). When the adaptive controller becomes active again the rotor compensation system is disabled and Rated Speed (05.008) is again adjusted by the adaptive controller. Therefore the rotor compensation system provides the necessary adjustment of the rated speed when the adaptive controller cannot operate. To give a smooth change when the adaptive controller becomes active Temperature compensated rated speed (05.057) is copied to the rated speed parameter for the active motor once during the transition.

Parameter | 05.055 Rotor Base Temperature
--- | ---
Short description | Defines the base temperature used to calculate the temperature of the rotor
Mode | RFC‑A
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‑A
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 Temperature compensated rated speed
--- | ---
Short description | Final rated speed value used by the drive including temperature compensation
Mode | RFC‑A
Minimum | 0.00 | Maximum | 33000.00
Default |  | Units | rpm
Type | 32 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 2
Coding | RO, ND, NC, PT

Temperature compensated rated speed (05.057) shows the rated speed value for the active motor that is being used by the drive including the effect of temperature compensation.

Parameter | 05.059 Maximum Deadtime Compensation
--- | ---
Short description | Shows the deadtime compensation used to compensate for dead-time effects in the inverter
Mode | RFC‑A
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‑A
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‑A
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 | 05.062 Saturation Breakpoint 2
--- | ---
Short description | Defines Saturation Breakpoint 2 within the saturation characteristic
Mode | RFC‑A
Minimum | 0.0 | Maximum | 100.0
Default | 0.0 | Units | %
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

See Saturation Breakpoint 1 (05.029).

Parameter | 05.063 Saturation Breakpoint 4
--- | ---
Short description | Defines Saturation Breakpoint 4 within the saturation characteristic
Mode | RFC‑A
Minimum | 0.0 | Maximum | 100.0
Default | 0.0 | Units | %
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

See Saturation Breakpoint 1 (05.029).