# Menu 5 − Motor Control

Mode: RFC‑S

The following table shows various definitions associated with controlling the motor. In each case the parameters used are given and how the definition is used.

Function | Parameters | Usage
Rated Current | Rated Current (05.007) | General definition of motor rated current Motor pre-heat Motor thermal model Sensorless mode low speed current injection level
Stator resistance | Stator Resistance (05.017) | Sensorless control reference frame High performance current control
Direct (flux) axis inductance | Ld (05.024) | Flux controller voltage control gains Sensorless control low speed mode High performance current control
Quadrature (torque) axis inductance with no load | No Load Lq (05.072) | Sensorless control operation High performance current control
Change of quadrature (torque) axis inductance with torque producing current | Lq At Defined Iq Test Current (05.078) Iq Test Current For Lq Measurement (05.075) | Sensorless control high speed mode
Change of quadrature (torque) axis inductance with flux producing current | Lq At Defined Id Test Current (05.084) Id Test Current For Lq Measurement (05.082) | Sensorless control high speed mode
Offset of minimum inductance point with torque producing current | Phase Offset Angle At Defined Iq Test Current (05.077) Iq Test Current For Lq Measurement (05.075) | Sensorless control low speed mode with signal injection
Rated voltage | Rated Voltage (05.009) | Flux control voltage limit Sensorless control set-up when changing from using position feedback Sensorless control initialisation of high speed mode when in low speed mode
Rated frequency | Rated Speed (05.008) Number Of Motor Poles (05.011) | Flux controller voltage control gains Sensorless control Sensorless control low/high speed mode thresholds
Rated torque angle | Rated Current (05.007) Ld (05.024) No Load Lq (05.072) Lq At Defined Iq Test Current (05.078) Iq Test Current For Lq Measurement (05.075) Lq At Defined Id Test Current (05.084) Id Test Current For Lq Measurement (05.082) Volts Per 1000rpm (05.033) | Salient motor control
Motor poles | Number Of Motor Poles (05.011) | Position feedback phasing error checking Flux voltage feed-forwards Mechanical to electrical position conversion Sensorless control maximum rate of change of flux angle Sensorless non-salient mode low speed feed-forwards Sensorless control electrical to mechanical speed conversion Stationary phasing test phase angle calculation Rotating phasing test phase angle calculation
Maximum current limits | Rated Current (05.007) for low saliency motors Rated torque angle (05.089) for high saliency motors | Current limit variable maximums, i.e. VM_MOTOR1_CURRENT_LIMIT.
Inductance ratio | No Load Lq (05.072) Ld (05.024) | Sensorless control check on inductance ratio Auto-tune check on inductance ratio
Magnet flux constant (Ke) | Volts Per 1000rpm (05.033) | Over-speed trip to prevent excessive voltage if drive disabled with flux weakening Rated torque angle calculation Voltage feed-forwards due to magnet flux Low speed sensorless control gains for non-salient motor operation Ultimate torque limit based on motor voltage and speed
Torque estimation | Stator Resistance (05.017) Ld (05.024) No Load Lq (05.072) Lq At Defined Iq Test Current (05.078) Iq Test Current For Lq Measurement (05.075) Lq At Defined Id Test Current (05.084) Id Test Current For Lq Measurement (05.082) Volts Per 1000rpm (05.033) No-load core loss (04.045) Rated Core Loss (04.046) | Estimated percentage torque
Torque per Amp (Kt) | Torque Per Amp (05.032) | Speed controller automatic gain set-up Inertia calculation in auto-tune tests 3 and 4

Parameter | 05.001 Output Frequency
--- | ---
Short description | Displays the 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 | Displays the r.m.s. line to line voltage at the a.c. terminals of the drive
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

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

Parameter | 05.003 Output Power
--- | ---
Short description | Displays the power flowing via the a.c. terminals of the drive
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

The 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. For Open-loop, RFC-A and RFC-S modes a positive value of power indicates power flowing from the drive to motor. For Regen mode a positive value of power indicates power flowing from the supply to the regen drive.

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

D.c. Bus Voltage (05.005) gives the voltage across the d.c. link of the drive.

Parameter | 05.007 Rated Current
--- | ---
Short description | Set to the rated current rated of the motor
Mode | RFC‑S
Minimum | −VM_RATED_CURRENT | Maximum | VM_RATED_CURRENT
Default | 0.000 | Units | A
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 3
Coding | RW, VM, RA

Rated Current (05.007) is used as follows:

1. To define the rated operating conditions for motor thermal protection. See Motor Thermal Time Constant 1 (04.015).
2. To define the range of the current limits.
3. In the motor control algorithm for Open-loop and RFC-A modes.

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 as follows:

1. Operation without position feedback, i.e. Sensorless Mode Active (03.078) = 1.
2. Where the motor operates above this speed and flux weakening is active.
3. In the motor thermal model.

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, RA

Voltage | Region | Default Value
200V | All | 230
400V | 50Hz | 400
400V | 60Hz | 460
575V | All | 575
690V | All | 690

The Rated Voltage (05.009) is the maximum continuous voltage that is applied to the motor. As with RFC-A mode some headroom must be allowed if high performance is required at higher speeds. It should be noted that this limit is not applied unless Enable High Speed Mode (05.022) is set to 1.

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 | 4 | 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 text string of the parameter and not the numeric value.

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 Pole).

If Number Of Motor Poles (05.011) = 0 the number of motor poles are calculated automatically as given below.

Pole pairs = 3 (6 Pole)

Parameter | 05.012 Auto-tune
--- | ---
Short description | Defines the auto-tune test to be performed
Mode | RFC‑S
Minimum | 0 | Maximum | 6
Default | 0 | Units |
Type | 8 Bit Volatile | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, NC

The following describes how an auto-tune test can be initiated and normal operation can be resumed after the test for RFC-S 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.
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 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.
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-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 |
Rated Speed (05.008) | Basic control |
Rated Voltage (05.009) | Basic control |
Number Of Motor Poles (05.011) | Basic control |
Stator Resistance (05.017) | Basic control | 1, 2
Ld (05.024) | Basic control | 1, 2
Maximum Deadtime Compensation (05.059) | Basic control | 1, 2
Current At Maximum Deadtime Compensation (05.060) | Basic control | 1, 2
Phase Offset At Iq Test Current (05.077) | Low speed sensorless control using injection mode | 6
Low Speed Sensorless Mode Current (05.071) | Low speed sensorless control using injection mode | 6
No-load Lq (05.072) | Sensorless control | 1, 2
Lq At The Defined Iq Test Current (05.078) | Sensorless control | 6
Lq At The Defined Id Test Current (05.084) | Sensorless control | 6
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 | 3, 4
Position Feedback Phase Angle (03.025) | Basic control with position feedback | 1, 2
Current Controller Kp Gain (04.013) | Basic control | 1, 2
Current Controller Ki Gain (04.014) | Basic control | 1, 2

Auto-tune test 1: Stationary test for basic control parameters
This test can be used to measure all the necessary parameters for basic control. (This test may not give such an accurate value for Position Feedback Phase Angle (03.025) as auto-tune test 2.)

1. A test is performed to locate the flux axis of the motor. If Minimal Movement Phasing Test Angle (05.016) is zero then motor inductance measurement is used and the motor should not move, otherwise a minimal movement method is used. See Minimal Movement Phasing Test Angle (05.016) for details.
2. A stationary test is performed to measure Stator Resistance (05.017), Maximum Deadtime Compensation (05.059) and Current At Maximum Deadtime Compensation (05.060).
3. If Enable Stator Compensation (05.049) = 1 then Stator Base Temperature (05.048) is made equal to Stator Temperature (05.046).
4. A stationary test is performed to locate the flux axis of the motor again in case the motor has moved during the previous test.
5. If sensorless mode is not selected (i.e. Sensorless Mode Active (03.078) = 0) then the position feedback phasing angle measured during stage 1 of this test is compared with the value measured during this stage of the test. If there is a difference of 30o or more then a Autotune 1.6 trip is initiated. Otherwise Position Feedback Phase Angle (03.025) is set up for the position from the position feedback interface selected with Motor Control Feedback Select (03.026).
6. If Minimal Movement Phasing Test Angle (05.016) is non-zero then the minimal movement method will have been used to locate the motor flux. If this is the case, then the level of current that was required to produce the necessary movement is stored in Minimal Movement Phasing Test Current (05.015).
7. A stationary test is performed to measure Ld (05.024) and No-load Lq (05.072).
8. Stator Resistance (05.017) and Ld (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.

It should be noted that because this is a stationary or minimal movement test, it is not possible to check the direction of the position feedback. If the motor power connection phase sequence is incorrect so that the position feedback counts in reverse when the drive applies a phase sequence U-V-W to operate in the forward direction then when the drive is enabled after the auto-tune the motor will jump thought 90o electrical and stop with a current in the motor defined by the current limits. This can be corrected by changing the drive output phase sequence with Reverse Output Phase Sequence (05.042) and then repeating the auto-tuning. This will make the motor rotate correctly in the direction defined by the position feedback rotation. If the position feedback direction is correct the motor will then rotate under control in the required direction, but if the position feedback direction is incorrect the motor will then rotate under control in the wrong direction.

When using any type of encoder with digital commutation signals (i.e. AB Servo) the absolute position is not fully defined until the motor has moved by between 1 and 2 electrical revolutions (i.e. between 120o and 240o mechanical for a 6 pole motor). This means that Position Feedback Phase Angle (03.025) can only be measured correctly using motor inductance measurement (i.e. Minimal Movement Phasing Test Angle (05.016) = 0). Also if Position Feedback Phase Angle (03.025) is measured for a motor using this type of position feedback using a stationary test when the motor has not moved since power-up, or after the position feedback is re-initialised, there can be an error of +/-30o in the result. When the motor subsequently moves, the drive synchronises more accurately to the commutation signal edges and adjusts Position Feedback Phase Angle (03.025) to be correct and then saves the value to NV memory in the drive. If a stationary auto-tune is performed and the motor is not moved by at least 2 electrical revolutions before powering down again this process is not carried out and the auto-tune should be repeated. When an encoder with digital commutation signals is used there is always an error of up to 30o in the phasing angle during starting until the motor has rotated by 1/3 of an electrical revolution. It should be noted that the +/-30o error in the phasing angle can increase this error to 60o and reduce the possible torque by up to 50%. Once the motor has rotated by 2 electrical revolutions full torque will be available.

The stationary test cannot be used with commutation only type devices, and test 2 below should be used instead.

Auto-tune test 2: Rotating test for basic control parameters
This test can be used to measure all the necessary parameters for basic control. The motor must be unloaded for this test. This test is likely to give a more accurate value for Position Feedback Phase Angle (03.025) than auto-tune test 1 for motors with low saliency or no saliency. If 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)) < 200 then the reluctance torque (due to saliency) compared to the torque derived from the magnet flux is too high and this test cannot be used. Note that if sensorless mode is selected Auto-tune 1 test is performed.

1. If sensorless mode is not selected (i.e. Sensorless Mode Active (03.078) = 0) then a rotating test is performed to locate the flux axis of the motor and Position Feedback Phase Angle (03.025) is set up for the position from the position feedback interface selected with Motor Control Feedback Select (03.026). This is done by rotating the motor by 2 electrical revolutions (i.e. up to 2 mechanical revolutions) in the required direction.
2. Steps 3 to 6 of the stationary test above are carried out.

Auto-tune test 3: Mechanical load measurement using signal injection
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 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. Motor And Load Inertia (03.018) and Inertia Times 1000 (04.033) are set up.

Auto-tune test 4: Mechanical load measurement using applied torque
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 Rated Speed (05.008) 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 unsucessful a 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 acheive 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.

Auto-tune test 5:
To be defined.

Auto-tune test 6: Locked rotor test for load dependent parameters
Note that this test is not impemented and needs to be fully defined. The following gives an outline of a possible test method.
If sensorless mode is selected then the rotor must be locked in position so that it does not move with the level of current defined by Iq Test Current For Inductance Measurement (05.075). It is possible to perform this test when the motor is not completely rigidly locked provided sensorless mode is not selected. This could be done for example where the motor shaft is prevented from turning by another motor connected to its shaft on a motor loading rig. The loading motor should be set up with zero speed reference and be able to prevent the test motor from accelerating with a level of current defined by Iq Test Current For Inductance Measurement (05.075). The test will apply a series of torque pulsations to the motor during the test and the loading motor should prevent excessive movement and the system response must be stable. If this test is carried out with position feedback the feedback device must be set up correctly and the Position Feedback Phase Angle (03.025) must be correct.

This is a fairly prolonged test which makes measurements of the motor inductance with a range of test currents in the d and q axis of the motor. Iq varies between zero and the level specified by Iq Test Current For Inductance Measurement (05.075). Id varies between the level specified by Id Test Current for Inductance Measurement (05.082) and zero. The results are analysed by the drive and Phase Offset At Iq Test Current (05.077), Low Speed Sensorless Mode Current (05.071), No-load Lq (05.072), Lq At The Defined Iq Test Current (05.078) and Lq At The Defined Id Test Current (05.084) are calculated. As the test is carried out at standstill the thermal model for the drive may initiate a trip at the higher current levels. If this is the case then either the test currents or the switching frequency will need to be reduced.

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 1.005 | The fine location of the motor flux during a minimal movement test failed.
Autotune 1.006 | The phasing offset angle is meaured 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 1.008 | An auto-tune has been attempted while the AMC is selected.
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 (except Autotune 1.008), Autotune 2 and Autotune 7 are disabled.

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, RA

The motor parameters used by the drive are derived from the star connected per phase equivalent circuit of a permanent magnet motor shown below.

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

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

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 | 1 | Units | kHz
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE, VM, RA

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.

Task |
Speed controller (RFC-A, RFC-S) | 250μs
D.c. link voltage controller | 1ms
Flux controller (RFC-A, RFC-S) | 1ms

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 | -1 | Maximum | 1
Default | -1 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text
‑1 | Limit
0 | Disable
1 | Enable

Care must be taken when high speed mode is not set to "disable" 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 not disabled 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 | 1145x 1000 / (Ke x √2) | 1145 / √2

Ke is the ratio between r.m.s. line to line voltage produced by the motor and the speed in V/1000rpm.

High speed mode is diabled as default (i.e. Enable High Speed Mode (05.022) = 0 (Disable)). 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 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.

If Enable High Speed Mode (05.022) = -1 (Limit) then 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 to protect the drive.

If Enable High Speed Mode (05.022) = 1 (Enable) then the motor flux is modified to limit the motor voltage to the level defined by Rated Voltage (05.009), but no trip is provided, and so it is possible to damage the drive without additional protection. 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.

Parameter | 05.023 D.c. Bus Voltage High Range
--- | ---
Short description | Displays the d.c. bus level but with a higher range
Mode | RFC‑S
Minimum | −VM_HIGH_DC_VOLTAGE | Maximum | VM_HIGH_DC_VOLTAGE
Default |  | Units | V
Type | 16 Bit Volatile | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RO, FI, VM, ND, NC, PT

D.c. Bus Voltage High Range (05.023) provides voltage feedback that has lower resolution and a higher range than D.c. Bus Voltage (05.005), and so it is possible to determine the d.c. link voltage even if this exceeds the level of the over-voltage trip. It should be noted that due to tolerances, D.c. Bus Voltage High Range (05.023) may not correspond exactly with the level given by D.c. Bus Voltage (05.005). In a system with parallel power modules where the control pod is remote from any of the power modules, this parameter always shows zero.

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, RA

See Stator Resistance (05.017).

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 flux in the motor and the motor 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 | 05.028 Torque Linearisation Disable
--- | ---
Short description | Torque Linearisation Disable
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 high saliency control is active (i.e. Active Saliency Torque Mode (05.066) = 2) the drive applies compensation to give approximately a linear realtionship between the torque reference and actual torque for speed and torque control modes. In some cases this may introduce unacceptable system noise. If Torque Linearisation Disable (05.028) is left at its default value of 0 the linearisation system is active. If Torque Linearisation Disable (05.028) is set to 1 then the linearisation system is disabled.

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.

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. This is used to define the voltage feed-forwards term in the motor control algorithms. It is also used to determine the trip speed if Enable High Speed Mode (05.022) is set to Limit mode.

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 drive 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.

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 if the inverter is too hot or the temperature ripple is too high.

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

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. If Minimum Switching Frequency is changed the new value will only become active when Switching Frequency is at or above the minimum value.

Parameter | 05.036 Auto-switching Frequency Step Size
--- | ---
Short description | Auto-switching frequency redcution 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 | Minuimum Switching Frequency
Mode | RFC‑S
Minimum | 0 | Maximum | VM_MIN_SWITCHING_FREQUENCY
Default | 0 | 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 allowed before the switching frequency is reduced. See Auto-switching Frequency Change (05.035).

Parameter | 05.041 Voltage Headroom
--- | ---
Short description | Voltage Headroom
Mode | RFC‑S
Minimum | 0 | Maximum | 20
Default | 10 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

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 | 05.059 Maximum Deadtime Compensation
--- | ---
Short description |
Mode | RFC‑S
Minimum | 0.000 | Maximum | 10.000
Default | 0.000 | Units | µs
Type | 16 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 3
Coding | RO, NC, PT

Maximum Deadtime Compensation (05.059) is the deadtime compensation 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. It should be noted that if the auto-tuning test is not performed and Maximum Deadtime Compensation (05.059) = 0 then dead-time compensation is disabled. Although it is not recommended, it is possible to disable dead-time compensation by setting Disable Deadtime Compensation (05.061) = 1.

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 User Save | 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 | 0 | Maximum | 3
Default | 1 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE

Value | Text | Description
0 | Injection | High frequency injection mode
1 | Non-salient | Non-salient motor mode
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

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).

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.

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: Non-salient
If the motor has low or no saliency (i.e. the conditions defined for Inductance cannot be met under the required load conditions) then this method can be used for low speed operation. This mode does not provide the same level of control as injection mode and the following should be considered:

1. Only speed control can be used when low speed mode operation is active.
2. When the low speed algorithm is active it will not be possible to produce more than approximately 60% to 70% of rated torque. Low Speed Sensorless Mode Current (05.071) defines a current applied in the motor d axis to aid starting. A value of 20% is suitable for most motors with a load of up to 60% rated torque. However, in some applications this level may need to be adjusted.
3. There may be some movement of the motor shaft in either direction as the motor starts.
4. It is not possible to measure the motor inertia using auto-tuning with Auto-tune (05.012) = 4.
5. Normally the ramp rate should not be slower than 5s/1000rpm when operating in the region below Rated Speed (05.008) / 10.
6. This mode is not intended to control the motor for prolonged periods at low speed, but is intended to allow the motor to be started from standstill to run outside the low speed region.
7. This mode is not intended to allow motor reversals. If the direction does need to be reversed, the motor should be stopped and any oscillations must die away, before the motor is restarted in the other direction.

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 is easier to set up and more flexible than "Non-salient" mode. 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 interia, 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 arbitary 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.

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:

1. 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.
2. To stop the motor the drive can simply be disabled or the run 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.

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 normally 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. If Saliency Torque Control Select (05.065) = 0 (disabled) torque is only produced from the magnet flux. If Saliency Torque Control Select (05.065) = 3 (auto) then torque can be produced from saliency and the mode to do this is selected automatically based on the value of Rated Torque Angle (05.089). If the torque produced by the magnet flux is more than twice the torque produced by saliency under rated conditions then Rated Torque Angle (05.089) < 30o, and under these conditions low saliency mode is selected, otherwise high saliency mode is selected. It is possible to specifically choose the saliency mode, Saliency Torque Control Select (05.065) = 1 gives low saliency mode and Saliency Torque Control Select (05.065) = 2 gives high saliency mode. It should be noted that if Rated Torque Angle (05.089) = 0 that the saliency mode remains disabled. Active Saliency Torque Mode (05.066) shows which mode is active. It should be noted that if the high saliency control mode is active it is not possible to detect a position feedback phasing error, and so Phasing Error are suppressed.

Parameter | 05.066 Active Saliency Torque Mode
--- | ---
Short description | Active Saliency Torque Mode
Mode | RFC‑S
Minimum | 0 | Maximum | 2
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

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 Required Over-current Trip Level
--- | ---
Short description | Required Over-current Trip Level
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. The trip level is nominally at the level of maximum controllable current which corresponds to Full Scale Current Kc (11.061). The value for Kc is given as an r.m.s. current, so if the instantaneous current from any of the drive phases exceeds the peak of a sinusoid with an r.m.s. value equal to Kc then the trip is initiated. Therefore the instantaneous trip level is √2 x Kc. The actual setting in the drive hardware is relatively coarse, and so the trip level may be different to the setting selected in Required Over-current Trip Level (05.067). Also for smaller drive sizes a margin is required to prevent cable charging currents from causing trips, and so for smaller drives the trip level may be significantly higher than Kc. For this reason Actual Over-current Trip Level (05.068) shows the actual trip level as a percentage of Kc. It should be noted that if the code tables stored in the power stage do not support this feature Actual Over-current Trip Level (05.068) will always be zero.

It is sometimes necessary to restrict the maximum instantaneous output current, particularly with permanent magnet motors to prevent de-magnetisation of the motor. Required Over-current Trip Level (05.067) can be used to select the required trip level as follows:

Required Over-current Trip Level (05.067) | Over-current trip level
0 | Maximum allowed over-current trip level for the drive which is Kc plus a margin for cable charging currents
1 to 9 | Maximum allowed over-current trip level x (Required Over-current Trip Level (05.067) + 1) x 100%
10 and above | Kc x Required Over-current Trip Level (05.067) / 100 The drive will not allow the actual over-current trip level to exceed the maximum allowed over-current trip level.

Values 1 to 9 are provided to give legacy support for parameter sets from some earlier software versions where 1 to 9 corresponded to 20, 30 .... 100% of the maximum allowed over-current trip level.

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 Required Over-current Trip Level (05.067).

Parameter | 05.070 Inverted Saturation Characteristic
--- | ---
Short description | 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 RFC-S mode when operating without position feedback. 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. If this parameter is not set and the motor has an inverted saturation characteristic this can be seen as follows:

1. Sudden jump in position during a stationary auto-tune with position feedback.
2. Sudden jump in position during auto-tuning in sensorless mode.
3. Very unstable operation or the motor runs in the wrong direction on starting in sensorless mode.

It should be noted that the saturation characteristic is also used to locate the flux axis when performing a stationary auto-tune or when measuring the phasing angle on enable. If a motor has an inverted saturation characteristic then Inverted Saturation Characteristic (05.070) should be set to one for these tests to operate correctly.

Parameter | 05.071 Low Speed Sensorless Mode Current
--- | ---
Short description | Maximum current limit for low speed injection mode or magnetising current for low speed non-salient mode
Mode | RFC‑S
Minimum | 0.0 | Maximum | 1000.0
Default | 20.0 | Units | %
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW, RA

See RFC Low Speed Mode (05.064).

Parameter | 05.072 No-load Lq
--- | ---
Short description | Defines the inducatance in the q axis with no current in the motor
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, RA

Motor q axis inductance with no current in the motor.

Parameter | 05.075 Iq Test Current For Inductance Measurement
--- | ---
Short description | Iq current level used for the inductance measurement auto-tuning
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

Maximum test current level used for Iq during auto-tuning when measuring the motor inductance and phase offset as a percentage of Rated Current (05.007). This value is also used by the sensorless control algorithm to define the motor inductance and a reference frame phase offset at different levels of Iq. The values of Lq At The Defined Iq Test Current (05.078) and Phase Offset At Iq Test Current (05.077) should be the values which correspond to the test current level and will be set up during auto-tuning when auto-tune test 6 is carried out. Alternatively these values can be set up by the user. For most motors Phase Offset At Iq Test Current (05.077) will be zero and have little affect on the performance, however Lq is likely to vary significantly with Iq and should be set up correctly for good performance. If Lq At The Defined Iq Test Current (05.078) or Iq Test Current For Inductance Measurement (05.075) are zero then the estimate of Lq will not be affected by the level of Iq, and if Phase Offset At Iq Test Current (05.077) or Iq Test Current For Inductance Measurement (05.075) are zero the phase offset will not be affected by the level of Iq.

Parameter | 05.077 Phase Offset At Iq Test 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, RA

Phase Offset At Iq Test 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 Iq Test Current For Inductance Measurement (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 Iq Test Current (05.077) is used for low speed RFC sensorless control using injection mode. A positive value advances the point of minimum inductance with positve 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 Test Current
--- | ---
Short description | Defines the inductance in the q axis when the defined q axis current is in the motor
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, RA

Motor q axis inductance with no current in the d axis and the current defined by Iq Test Current For Inductance Measurement (05.075) in the q axis of the motor. If this parameter is left at its default value of zero then no compensation is made to the value of Lq with changes in Iq.

Parameter | 05.082 Id Test Current for Inductance Measurement
--- | ---
Short description | Id current level used for the inductance measurement auto-tuning
Mode | RFC‑S
Minimum | -100 | Maximum | 0
Default | -50 | Units | %
Type | 8 Bit User Save | Update Rate | Background Read
Display Format | Standard | Decimal Places | 0
Coding | RW

Minimum test current level used for Id during auto-tuning when measuring the motor inductance as a percentage of Rated Current (05.007). This is then used in a similar way as Iq Test Current For Inductance Measurement (05.075) to estimate the value of Lq used in the control algorithms as Id changes. If Lq At The Defined Id Test Current (05.084) or Id Test Current for Inductance Measurement (05.082) are set to zero then no compensation is made for changes in Lq with Id.

Parameter | 05.084 Lq At The Defined Id Test Current
--- | ---
Short description | Defines the inductance in the q axis when the defined d axis current is in the motor
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, RA

Motor q axis inductance with no current in the q axis and the current defined by Id Test Current for Inductance Measurement (05.082) in the d axis of the motor. If this parameter is left at its default value of zero then no compensation is made to the value of Lq with changes in Id.

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

In sensorless mode the drive estimates a value for Lq to use in the control algorithm. Estimated Lq (05.088) shows the calculated value.

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

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 between the torque producing current axis of the reference frame and the current vector required to produce the torque. Ideally the following parameters should be set to the correct values for the motor: Rated Current (05.007), Ld (05.024), No-load Lq (05.072), Volts Per 1000rpm (05.033) ,Iq Test Current For Inductance Measurement (05.075), Lq At The Defined Iq Test Current (05.078), Id Test Current for Inductance Measurement (05.082) and Lq At The Defined Id Test Current (05.084). However, if Lq At The Defined Iq Test Current (05.078) or Lq At The Defined Id Test Current (05.084) are left at their default value of zero then the effect of either Iq or Id respectively on the q axis inductance (Lq) is not taken into account in calculating the rated torque angle. The torque angle under rated conditions is only calculated and written to Rated Torque Angle (05.089) if Saliency Torque Control Select (05.065) is set to one and the motor is salient under no-load conditions, i.e. Ld (05.024) ≤ No-load Lq (05.072).