# Menu 5 − Motor Control

Mode: RFC‑A

The drive can operate under Open Loop and RFC modes with respect to frequency and current control and can drive asynchronous machines. The open loop asynchronous control is further broken down into vector and fixed boost modes.

Open-loop mode

RFC operation

Parameter | 05.001 Output Frequency
--- | ---
Short description | Displays the output frequency of the drive
Mode | RFC‑A
Minimum | −VM_SPEED_FREQ_REF | Maximum | VM_SPEED_FREQ_REF
Default |  | Units | Hz
Type | 32 Bit Volatile | Update Rate | 16ms
Display Format | Standard | Decimal Places | 2
Coding | RO, FI, VM, 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‑A
Minimum | −VM_AC_VOLTAGE | Maximum | VM_AC_VOLTAGE
Default |  | Units | V
Type | 16 Bit Volatile | Update Rate | 16ms
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‑A
Minimum | −VM_POWER | Maximum | VM_POWER
Default |  | Units | kW
Type | 32 Bit Volatile | Update Rate | 16ms
Display Format | Standard | Decimal Places | 2
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. A positive value of power indicates power flowing from the drive to the motor.

The maximum power is VM_POWER[MAX] = √3 x VM_AC_VOLTAGE[MAX] x Full Scale Current Kc (11.061) / 1000

Parameter | 05.004 Motor Rpm
--- | ---
Short description | Displays the Final Demand Reference in units of rpm
Mode | RFC‑A
Minimum | -80000 | Maximum | 80000
Default |  | Units | rpm
Type | 32 Bit Volatile | Update Rate | Background write
Display Format | Standard | Decimal Places | 0
Coding | RO, FI, ND, NC, PT

Motor Rpm (05.004) = 60 x Frequency / Pole pairs

where
Pole pairs = the numeric value of Number Of Motor Poles (i.e. 3 for a 6 pole motor)

The frequency used to derive the Motor Rpm (05.004) is the Final Demand Reference (03.001). The maximum and minimum values allow for a 10% over-shoot of the speed.

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

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

Parameter | 05.006 Motor Rated Frequency
--- | ---
Short description | Set to the rated frequency of the motor
Mode | RFC‑A
Minimum | 0.00 | Maximum | 550.00
Default | See exceptions below | Units | Hz
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 2
Coding | RW

Region | Default Value
50Hz | 50.00
60Hz | 60.00

Motor Rated Frequency (05.006), Motor 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. 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.

Parameter | 05.007 Motor Rated Current
--- | ---
Short description | Set to the rated current rated of the motor
Mode | RFC‑A
Minimum | −VM_RATED_CURRENT | Maximum | VM_RATED_CURRENT
Default | 0.00 | Units | A
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 2
Coding | RW, VM, RA

Motor Rated Current is used as follows:

1. To define the rated operating conditions for motor thermal protection. See Thermal Protection Mode (04.016).
2. To define the range of the current limits.
3. In the motor control algorithm for Open-loop and Closed Loop asynchronous modes.

Parameter | 05.008 Motor Rated Speed
--- | ---
Short description | Set to the rated speed of the motor
Mode | RFC‑A
Minimum | 0.0 | Maximum | 80000.0
Default | See exceptions below | Units | rpm
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW

Region | Default Value
50Hz | 1500.0
60Hz | 1800.0

Motor Rated Speed (05.008) is not used by the motor control algorithms, but it is used by the motor thermal protection system.

Parameter | 05.009 Motor 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 | 16ms
Display Format | Standard | Decimal Places | 0
Coding | RW, VM, RA

Voltage | Region | Default Value
110V | All | 230
200V | All | 230
400V | 50Hz | 400
400V | 60Hz | 460
575V | All | 575
690V | All | 690

The Motor 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 Motor Rated Voltage (05.009) if this is equal to or above the supply voltage. If high transient performance is required at higher speeds then Motor 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 Motor Rated Voltage (05.009) to a value other than the motor nameplate value. If this is the case the Motor Rated Frequency (05.006) and Motor Rated Speed (05.008) should be set up as follows:

K = Motor Rated Voltage (05.009) / motor rated voltage

Motor Rated Frequency (05.006) = motor rated frequency x K

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

The Motor Rated Voltage (05.009), Motor 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 Motor 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 Motor 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 | 0.00 | Maximum | 1.00
Default | 0.85 | Units |
Type | 16 Bit User Save | Update Rate | Background read/write
Display Format | Standard | Decimal Places | 2
Coding | RW, RA

Motor 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 Motor 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 Motor 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 Motor 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 | 16
Default | 0 | Units | PolePairs
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, BU

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

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

Parameter | 05.012 Auto-tune
--- | ---
Short description | Defines the auto-tune test to be performed
Mode | RFC‑A
Minimum | 0 | Maximum | 3
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 Open loop, Closed loop 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 (see Menu 06), or the Final drive run (see Menu 06) is inactive and Hold Zero Frequency (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. It should be noted that the motor may jump by up to half an electrical revolution in either direction at the start of auto-tuning test 1 in Synchronous mode whatever the value of Reverse Select (01.012), but after the initial jump the remainder of the test will be carried out in the correct direction.
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 = 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 Frequency (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). However, the transition from the Disable state to the Stop state cannot be made in closed loop mode if Auto-tune (05.012) is non-zero. This is intended to prevent the drive entering the Stop state when an auto-tune test is required, but the enable is applied before the run as the control of the motor may rely on position estimation.

The following describes the effects of the auto-tune test on the drive :

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. Only when the whole test is completed, are 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 on the drive.

RFC-A mode
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
Motor Rated Frequency (05.006) | Basic control |
Motor Rated Current (05.007) | Basic control |
Motor Rated Speed (05.008) | Basic control |
Motor Rated Voltage (05.009) | Basic control |
Motor Rated Power Factor (05.010) | Basic control | 2
Number Of Motor Poles (05.011) | Basic control |
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) | Frequency controller set-up and torque feed-forwards | 3
Current Controller Kp Gain (04.013) | Basic control | 1, 2
Current Controller Ki Gain (04.014) | Basic control | 1, 2

Auto-tune test 1: Basic control parameters
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).
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.

Auto-tune test 2: Basic control and improved performance parameters
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 Motor 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 Motor 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 motor should be unloaded for this test.

Auto-tune test 3: Mechanical load measurement
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 Motor 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 unsuccessful 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 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. The motor must be stationary at the start of the test.

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

Trip | Reason | Trip can occur in test
Autotune Stopped | The final drive enable or the final drive run were removed before the test was completed. | All
Resistance | The measured value of Stator Resistance (05.017) exceeded the range of the parameter. | 1, 2
Autotune 3 | The measured inertia exceeds the parameter range. | 3

Parameter | 05.013 Flux Optimisation Select
--- | ---
Short description | Set to 1 to enable to reduce the flux
Mode | RFC‑A
Minimum | 0 | Maximum | 1
Default | 0 | Units |
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

If Flux Optimisation Select, Dynamic V To F Select (05.013) = 1, the flux is reduced so that the Magnetising Current (04.017) is equal to the Torque Producing Current (04.002) to optimise copper losses and reduce iron losses in the motor under low load conditions. The steady state range of the Magnetising Current (04.017) is limited between IMRated / 2 and IMrated.

Parameter | 05.015 Low Frequency Voltage Boost
--- | ---
Short description | Defines the level of voltage boost at 0Hz when using a fixed V to F relationship
Mode | RFC‑A
Minimum | 0.0 | Maximum | 25.0
Default | 3.0 | Units | %
Type | 16 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 1
Coding | RW, BU

* 3.0% up to Size D, 2.0% for Size 7 and 8, and 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.

Parameter | 05.017 Stator Resistance
--- | ---
Short description | Defines the resistance of the motor stator
Mode | RFC‑A
Minimum | 0.0000 | Maximum | 99.9999
Default | 0.0000 | Units | Ω
Type | 32 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 4
Coding | RW, RA

Asynchronous machines:
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

Parameter | 05.018 Maximum Switching Frequency
--- | ---
Short description | Defines the maximum switching frequency that can be used by the drive
Mode | RFC‑A
Minimum | −VM_MAX_SWITCHING_FREQUENCY | Maximum | VM_MAX_SWITCHING_FREQUENCY
Default | 3 | Units | kHz
Type | 8 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW, TE, VM, RA

Value | Text | Description
2 | 2 | 2kHz switching frequency
3 | 3 | 3kHz switching frequency
4 | 4 | 4kHz switching frequency
5 | 6 | 6kHz switching frequency
6 | 8 | 8kHz switching frequency
7 | 12 | 12kHz switching frequency
8 | 16 | 16kHz switching frequency

Maximum Switching Frequency (05.018) should be set to the required PWM switching frequency. The drive inverter will operate at this frequency unless Auto-switching Frequency Change Disable (05.035) = 0 and the inverter temperature exceeds the threshold for automatic switching frequency reduction (see Inverter Temperature (07.034)). 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 of 1ms.

Note: 0.667kHz and 1KHz switching frequencies are not supported in RFC-A mode.

As default Auto-switching Frequency Change Disable (05.035) = 0 and the system described above is always active. If Auto-switching Frequency Change Disable (05.035) = 1 then the automatic switching frequency changing system is disabled. If Auto-switching Frequency Change Disable (05.035) = 2 the system is active, but does not take into account the device temperature at low output frequencies.

We recommend that a minimum ratio of 12:1 for the switching frequency compared to the output frequency is used.

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 inducatance 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, RA

See Stator Resistance (05.017).

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, RA

See Stator Resistance (05.017).

Parameter | 05.026 High Dynamic Performance Enable
--- | ---
Short description | Set to 1 to enable slip 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

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 frequencies.

Parameter | 05.028 Flux Control Compensation Disable
--- | ---
Short description | Set to 1 to disable Flux Control Compensation
Mode | RFC‑A
Minimum | 0 | Maximum | 0
Default | 0 | Units |
Type | 1 Bit User Save | Update Rate | Background read
Display Format | Standard | Decimal Places | 0
Coding | RW

If Flux Control Compensation Disable (05.028) = 0 the conversion from the Final Torque Reference (04.003) to Final Current Reference (04.004) uses the estimated level of motor flux. This is the preferred method of control as it ensures that the gain of the system remains constant in speed control mode and it gives the correct relationship between torque and current in torque control modes. However, it is possible to get instability in speed control mode when flux weakening is active at high speed if the Motor Rated Speed (05.008) is set to an incorrect value. If Flux Control Compensation Disable (05.028) = 1 the compensation for flux level is disabled which can sometimes prevent instability under these conditions.

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 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 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 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 / [((Motor Rated Speed x 2π) / 60) x ITRated]

where

ITrated is the rated torque producing current and

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

Torque Per Amp (05.032) is used in the automatic calculation of the speed controller gains.

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 Disable
--- | ---
Short description | Set to 1 to prevent the drive from changing between switching frequencies
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

See Maximum Switching Frequency (05.018).

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

Value | Text | Description
2 | 2 | 2kHz switching frequency
3 | 3 | 3kHz switching frequency
4 | 4 | 4kHz switching frequency
5 | 6 | 6kHz switching frequency
6 | 8 | 8kHz switching frequency
7 | 12 | 12kHz switching frequency
8 | 16 | 16kHz switching frequency

See Maximum Switching Frequency (05.018).

Parameter | 05.038 Minimum Switching Frequency
--- | ---
Short description | Defines the minimum switching frequency that can be used by the drive
Mode | RFC‑A
Minimum | 0 | Maximum | VM_MAX_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, RA

Value | Text | Description
0 | 0.667 | 667Hz switching frequency
1 | 1 | 1kHz switching frequency
2 | 2 | 2kHz switching frequency
3 | 3 | 3kHz switching frequency
4 | 4 | 4kHz switching frequency
5 | 6 | 6kHz switching frequency
6 | 8 | 8kHz switching frequency
7 | 12 | 12kHz switching frequency
8 | 16 | 16kHz switching frequency

Minimum Switching Frequency (05.038) defines the minimum frequency limit used if the inverter thermal model is actively reducing the switching frequency due to temperature.
Note that parameter Maximum Switching Frequency (05.018) takes priority over parameter Minimum Switching Frequency (05.038) so is not limited by parameter Minimum Switching Frequency (05.038). The actual minimum switching frequency limit used is the lower of Maximum Switching Frequency (05.018) and Minimum Switching Frequency (05.038).

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 write
Display Format | Standard | Decimal Places | 1
Coding | RW

Spin Start Boost (05.040) is used by the algorithm that detects the frequency of a spinning motor when the drive is enabled and Catch A Spinning Motor (06.009) ≥ 1. For smaller motors the default value of 1.0 is suitable, but for 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 frequency 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 | 05.042 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 | 05.059 Maximum Deadtime Compensation
--- | ---
Short description | Maximum Deadtime Compensation
Mode | RFC‑A
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‑A
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‑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).

Parameter | 05.081 Change to maximum drive switching frequency at low output current
--- | ---
Short description | Change to maximum drive switching frequency at low output current
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

Open-loop and RFC modes. User set maximum switching frequencies 2kHz to 6kHz only.

Swaps to 16kHz if the output current magnitude is less than 30% (Frame sizes 1-4) and 20% (Frame sizes 5 and above) drive OI.AC limit for longer than 100ms.

Swaps back immediately if the output current magnitude is greater than 15% drive OI.AC limit.

The original switching frequency may still be under the control of the inverter thermal model. This feature is disabled if the thermal model or user have changed the switching frequency within the last 10 seconds.

Parameter | 05.084 Low Frequency Estimator Threshold
--- | ---
Short description | Controls the RFC-A estimator threshold
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

Open-Loop mode:
In resistor compensation open loop modes (Control Mode (05.014) set to 0, 1, 3, and 4):

If the rated slip frequency is non-zero, the rated slip frequency (see Motor Rated Frequency (05.006) can be modified when the output frequency is below one third of the motor rate frequency to provide a torque boost.
The modification consists of an addition to the calculated slip frequency controlled by the user parameter Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084).The addition is equal to Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084) at zero Hz falling linearly to 0.0% at one third of the motor rated frequency.

If the rated slip frequency is zero, the amount of stator resistor compensation can be modified when the output frequency is below one tenth of the motor rate frequency to provide a torque boost. The modification consists of an addition to the calculated stator resistor compensation controlled by the user parameter Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084).The addition is equal to Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084). at zero Hz falling linearly to 0.0% at one tenth of the motor rated frequency.

In fixed boost tapered open loop control (Control Mode (05.014) set to 6):

Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084) sets the frequency at which the taper of the slip begins. This is expressed in Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084) as a percentage of the motor rated frequency, Motor Rated Frequency (05.006) . See #5.014 = 6.

RFC-A mode:

If Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084) = 0.0% (default) the RFC-A speed estimator is used when the ramp output is greater than the rated motor frequency divided by 64.
If Low Frequency Estimator Threshold, Low Frequency Slip Boost (05.084) > 0.0% , the RFC-A speed estimator is used when the ramp output is greater than the rated motor frequency divided by 128.