4.5 Torque control by Real sensorless vector control, vector
4.5.3 Setting procedure of vector control (torque control)
CAUTION
⋅ The carrier frequencies are selectable from among 2k, 6k, 10k, 14kHz for vector control.
(2k and 6kHz for the 75K or higher)
Vector Vector Vector
Test run
Perform secure wiring. (Refer to page 36.)
Set the motor and encoder. (Pr. 71, Pr. 359, Pr. 369)
As required
ã Perform offline auto tuning. (Pr. 96) (refer to page 189).
ã Select online auto tuning. (Pr. 95) (refer to page 199).
ã Manual input torque control gain adjustment (refer to page 130) Set the motor capacity and the number of motor poles. (Pr. 80, Pr. 81)
(Refer to page 92.)
Set the motor capacity (kW) in Pr. 80 Motor capacity and set the number of motor poles in Pr. 81 Number of motor poles.
(V/F control is performed when the setting is "9999" (initial value).) Mount the FR-A7AP/FR-A7AL (option).
Set Pr. 71 Applied motor, Pr. 359 Encoder rotation direction and Pr. 369 Number of encoder pulses according to the motor and encoder used.
(Refer to page 38.)
Select a control method. (Refer to page 92.)
Set either "1" (torque control), "2" (speed-torque switchover) or "5"
(position-torque switchover) in Pr. 800 and make torque control valid.
Set the torque command. (Pr. 804) (Refer to page 125.)
Set the speed limit. (Pr. 807) (Refer to page 127.)
Torque control by Real sensorless vector control, vector control
4
P ARAME T E RS
4.5.4 Torque command (Pr. 803 to Pr. 806)
* This parameter allows its setting to be changed during the operation in any operation mode even if "0 (initial value) or 1" is set in Pr. 77 Parameter write selection.
(1) Control block diagram
(2) Torque command (Pr. 804 = "0" (initial value)) by analog input (terminal 1) Torque command source for torque control can be selected.
Parameter
Number Name Initial
Value Setting
Range Description
803 Constant power range torque characteristic selection
0
0 Constant motor output
command Select the torque command in the constant power region by torque command setting.
1 Constant torque command
804 Torque command
source selection 0
0
Torque command input Speed limit input method Torque command by terminal1 analog input
(Refer to page 300)
As set in Pr. 807.
1 Torque command by parameter setting (Pr. 805 or Pr. 806) (-400% to 400%)
2 Torque command by pulse train input (FR-A7AL)
3 Torque command with using CC-Link communication (FR-A7NC/FR-A7NCE)
The Pr. 808 and Pr. 809 settings are speed limit.
4 12-bit/16-bit digital input (FR-A7AX) As set in Pr. 807.
5 Torque command with using CC-Link communication (FR-A7NC/FR-A7NCE)
The Pr. 808 and Pr. 809 settings are speed limit.
6 As set in Pr. 807.
805 * Torque command
value (RAM) 1000%
600 to 1400%
Writes the torque command value to the RAM.
On the assumption that 1000% is 0%, the torque command is set by an offset from 1000%.
806 * Torque command
value (RAM,EEPROM) 1000%
600 to 1400%
Writes the torque command value to the RAM and EEPROM.
On the assumption that 1000% is 0%, the torque command is set by an offset from 1000%.
⋅ Torque command is given by voltage (current) input to terminal 1.
⋅ When torque command is input from terminal 1, set "3 or 4" in Pr. 868 Terminal 1 function assignment.
⋅ Torque command by analog input can be calibrated using calibration parameter C16 (Pr. 919) to C19 (Pr. 920) . (Refer to page 300 )
Sensorless Sensorless
Sensorless VectorVectorVector
Analog input Parameter [Pr. 805, Pr. 806] 16-bit digital input (FR-A7AX)
0 1,3,5,6 4 2
[Pr. 804] Torque command source selection
Speed limit input + -
Speed limit value Speed estimated
value
Speed limit value Speed estimated
value
Real sensorless vector control Vector control Speed control (proportional control)
Speed estimator
Torque control +
-
Motor
Encoder Pulse train input (FR-A7AL)
Torque command 150%
-100%
(-10V)
0 100%
(+10V) -150%
Terminal 1 analog input
(3) Torque command using parameters (Pr. 804 = "1")
(4) Torque command by pulse train input (Pr.804 = "2")
Torque command is set by pulse train input from FR-A7AL (plug-in option).
FR-A7AL needs to be installed for this function.
(5) Torque command with using CC-Link communication (Pr. 804 = "1, 3, 5, 6")
⋅ Torque command setting is available through FR-A7NC (CC-Link communication option) or FR-A7NCE (CC-Link IE Field communication option).
*1 Setting from the operation panel and the parameter unit is also available.
*2 Negative torque command is unavailable from the operation panel or parameter unit.
(6) Torque command by 16-bit digital input (Pr. 804 = 4)
⋅ Give a torque command by 16-bit or 12-bit digital input using the FR-A7AX (plug-in option).
⋅ Torque command value can be set by setting Pr. 805 Torque command value (RAM) or Pr. 806 Torque command value (RAM,EEPROM) .
⋅ For Pr. 805 or Pr. 806, the torque command is set by an offset from 1000% on the assumption that 1000% is 0%.
The relationship between the Pr. 805 or Pr. 806 setting and actual torque command value at this time is shown on the left.
⋅ When changing the torque command frequently, write to Pr. 805. Performing frequent parameter write to Pr. 806 will shorten the life of the EEPROM.
⋅ Torque command through FR-A7NCE (CC-Link IE Field communication option) is valid only when FR-A7NCE is installed.
REMARKS
⋅ When torque command is set in Pr. 805 (RAM), powering OFF the inverter will erase the changed parameter values. Therefore, the parameter value available when power is switched ON again is the value set in Pr. 806(EEPROM).
CAUTION
⋅ When giving a torque command by parameter setting, set the speed limit value to an appropriate value to prevent overspeed.
(Refer to page 127.)
REMARKS
For details of the setting with the FR-A7AL, refer to the FR-A7AL instruction manual.
Pr.804 setting
Torque Command Source
Setting Range Increments
FR-A7NC FR-A7NCE
1 Torque command by Pr. 805 or Pr. 806 *1 Same operation as setting value "3"
600 to 1400 (-400 to 400%) 1%
3
Torque command by Pr. 805 or Pr. 806 *1
Torque command from remote resister
(RWw1 or RWwC) Torque command from remote
resister (RWw2 or RWw3) 5
Torque command by Pr. 805 or Pr. 806 *1
-32768 to 32767 (two's complement)
(-327.68% to 327.67%) *2
0.01%
Torque command from remote resister
(RWw1 or RWwC) Torque command from remote
resister (RWw2 or RWw3)
6 Torque command by Pr. 805 or Pr. 806 *1 Same operation as setting value "5"
REMARKS
⋅ For details of the setting with the FR-A7NC or FR-A7NCE, refer to the instruction manual of each options.
REMARKS
⋅ For details of the setting with the FR-A7AX, refer to the FR-A7AX instruction manual.
Torque command value 400%
600%
1000% 1400%
-400%
Pr.805,Pr.806 settings
Torque command value
=Pr.805(or Pr.806)-1000%
Torque control by Real sensorless vector control, vector control
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P ARAME T E RS
(7) Change the torque characteristics in the constant power (Pr. 803)
4.5.5 Speed limit (Pr. 807 to Pr. 809)
(1) Control block diagram
⋅ Due to the motor characteristics, torque is reduced at or above the base frequency. Set "1" in Pr. 803 Constant power range torque characteristic selection when you want to keep the torque to be constant even at or above the base frequency.
♦Parameters referred to♦
Pr. 868 Terminal 1 function assignment Refer to page 100
Calibration parameter C16 (Pr. 919) to C19 (Pr. 920) (terminal 1 bias, gain torque) Refer to page 300
Set the speed limit value to prevent overspeed of the motor in case the load torque becomes less than the torque command value, etc. during torque control operation.
Parameter
Number Name Initial Value Setting
Range Description
807 Speed limit selection 0
0 Use the speed command value during speed control as speed limit.
1 According to Pr. 808 and Pr. 809 , set the speed limit in forward and reverse rotation directions individually.
2
Forward/reverse rotation speed limit
The analog voltage of the terminal 1 input is used to make speed limit.
The speed limit of the forward rotation and reverse rotation is switched according to the polarity.
808 Forward rotation speed
limit 60Hz 0 to120Hz Set the speed limit for the forward rotation direction.
809 Reverse rotation speed
limit 9999
0 to120Hz Set the speed limit of the reverse rotation side.
9999 As set in Pr. 808 . Speed
Base speed Torque
Pr. 803= 1:
constant torque command Pr. 803= 0:
constant power command (torque reduction) Constant power range
Constant torque range
Sensorless Sensorless
Sensorless VectorVectorVector
Forward/reverse rotation speed limit Same method as speed command input Parameter(Pr. 808, Pr. 809)
0 1 2
Pr. 807 Speed limit selection Torque command
+ -
Speed estimated value < speed limit value +
-
Torque control Motor
Encoder
Speed estimator Real sensorless vector control
Vector control Speed control (proportional control) Speed estimated value speed limit value
(3) Set the forward rotation and reverse rotation individually (Pr. 807 = "1")
Set the speed limit during forward rotation using Pr. 808 Forward rotation speed limit and the speed limit during reverse rotation using Pr. 809 Reverse rotation speed limit.
The speed during forward and reverse rotation is limited at the setting value of Pr. 808 when "9999" (initial value) is set in Pr. 809 .
(2) Use the speed command for speed control (Pr. 807 = "0" initial value)
⋅ Set the speed limit in the same method as speed setting for speed control (speed setting by the PU (FR-DU07/
FR-PU07/FR-PU04), multi-speed setting, options, etc.)
⋅ According to the acceleration time set in Pr. 7 Acceleration time, the limit level is increased from 0Hz upon turning ON of the start signal, and when the start signal turns OFF, the speed limit level is decreased from the then speed limit level to the DC injection brake operation speed in Pr. 10 to a stop in accordance with the deceleration time set in Pr. 8 Deceleration time.
REMARKS
⋅ When the above speed limit command is greater than the Pr. 1 Maximum frequency value, the speed limit value is the Pr. 1 Maximum frequency value, and when the speed limit command is less than the Pr. 2 Minimum frequency value, the speed limit value is the Pr. 2 Minimum frequency value. Similarly when the speed limit command is smaller than Pr. 13 Starting frequency , the speed limit value is 0Hz.
⋅ When speed limit is set by analog input, perform calibration of the analog input terminal 1, 2 and 4. (Refer to page 300.) CAUTION
When speed limit is set by the analog command (terminal 1,2,4), turn OFF the external signals (RH, RM, RL). If any of external signals (RH, RM, RL) is ON, multi-speed limits are valid.
STF(STR) ON OFF
Speed Forward rotation Speed setting value during speed control
Pr.7
Time Torque controllable range
The speed setting value is a speed limit value.
Pr.8
Reverse rotation
Pr.809 Speed
Reverse rotation Pr.808
Torque controllable range
150 150
Output torque (%)
0
Pr.7 Pr.8
STF(STR) ON OFF
Speed limit Speed limit
Speed limit
Speed limit Forward rotation
Pr.808
Pr.809 Pr.809 Pr.809 Torque controllable range Torque controllable range Torque controllable range Time Time Time Forward rotation
Reverse rotation
Torque control by Real sensorless vector control, vector control
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P ARAME T E RS
(4) Forward rotation/reverse rotation speed limit (Pr. 807 = "2")
⋅ When making a speed limit using analog input from terminal 1, the speed limit of the forward and reverse rotation can be switched according to the polarity of voltage.
⋅ Forward/reverse rotation speed limit is valid when Pr. 868 Terminal 1 function assignment = "5".
⋅ For 0 to 10V input, set the forward rotation speed limit. The reverse rotation speed limit at this time is the value of Pr.1 Maximum frequency.
⋅ For -10 to 0V input, set the reverse rotation speed limit. The forward rotation speed limit at this time is the value of Pr. 1 Maximum frequency .
⋅ The maximum speed of both the forward and reverse rotations is Pr. 1 Maximum frequency .
REMARKS
⋅ When making speed limit from terminal 1, make calibration of terminal 1. (Refer to page 300.) CAUTION
When the actual speed reaches or exceeds the speed limit value, torque control is switched to speed control to prevent overspeed.
(SL) appears ON the operation panel during speed limit operation and the OL signal is output.
♦Parameters referred to♦
Pr. 1 Maximum frequency, Pr. 2 Minimum frequency Refer to page 157 Pr. 7 Acceleration time, Pr. 8 Deceleration time Refer to page 172 Pr. 13 Starting frequency Refer to page 175
Pr. 4 to Pr. 6, Pr. 24 to Pr. 27, Pr. 232 to Pr. 239 (Multi-speed operation) Refer to page 165 Pr. 868 Terminal 1 function assignment Refer to page 285
Pr. 125, Pr. 126, C2 to C7, C12 to C15 (frequency setting voltage (current) bias/gain) Refer to page 294 Pr.7
ON OFF Start signal
Speed
Time
Speed
Forward rotation
Reverse rotation
Output torque (%) 0
Speed
Reverse rotation Forward rotation
Output torque (%) Terminal 1 input Pr.1
0 Torque controllable range
Torque controllable range
Torque controllable range
Terminal 1 input
Terminal 1 input (-10 to 0V) The reverse rotation speed limit
150 150 150 150
Pr.1
Pr.8
Pr.1 Pr.7
ON Start signal OFF
Speed
Time Terminal 1 input (0 to 10V)
The forward rotation speed limit
Pr.8
Pr.1
Torque controllable range When terminal 1 input is "-10 to 0V" When terminal 1 input is "0 to 10V"
The reverse rotation speed limit
The forward rotation speed limit
4.5.6 Gain adjustment of torque control (Pr. 824, Pr. 825, Pr. 834, Pr. 835)
(1) Adjustment of current loop proportional (P) gain
⋅ For general adjustment, make setting within the range 50 to 200% as a guideline.
⋅ Set the proportional gain for torque control.
⋅ Increasing the value improves trackability in response to a current command change and reduces current variation with disturbance. However, a too large gain will cause instability, generating harmonic torque pulsation.
(2) Adjustment of current control integral time
⋅ Set the integral time of current control during torque control.
⋅ A small value enhances the torque response level, but a too small value will cause current fluctuation.
⋅ Decreasing the value shortens the time taken to return to the original torque if current variation with disturbance occurs.
(3) Use multiple gains
⋅ When you want to change the gain according to applications, switch multiple motors with one inverter, etc., use Torque control P gain 2 and Torque control integral time 2 .
⋅ Pr. 834 Torque control P gain 2 and Pr. 835 Torque control integral time 2 are valid when the RT signal is ON.
Although stable operation is possible with the initial value, make adjustment when any of such phenomena as unusual motor and machine vibration/noise and overcurrent has occurred.
Parameter
Number Name Initial Value Setting
Range Description
824 Torque control P gain 1 100% 0 to 200% Set the current loop proportional gain.
100% is equivalent to 2000rad/s.
825 Torque control integral
time 1 5ms 0 to 500ms Set the current loop integral compensation time.
834 Torque control P gain 2 9999 0 to 200% Set the current loop proportional gain when the RT signal is ON.
9999 Without torque control P gain 2 function 835 Torque control integral
time 2 9999
0 to500ms Set the current loop integral compensation time when the RT signal is ON.
9999 Without torque control integral time 2 function
REMARKS
⋅ The RT signal acts as the second function selection signal and makes the other second functions valid. (Refer to page 235.)
⋅ The RT signal is assigned to the terminal RT in the initial setting. By setting "3" in any of Pr. 178 to Pr. 189 (input terminal function selection) , you can assign the RT signal to the other terminal.
Sensorless Sensorless
Sensorless VectorVectorVector
Torque control by Real sensorless vector control, vector control
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P ARAME T E RS
(4) Adjustment procedure
Make adjustment when any of such phenomena as unusual motor and machine vibration/noise/current and overcurrent has occurred.
1)Check the conditions and simultaneously change the Pr. 824 value.
2)If you cannot make proper adjustment, change the Pr. 825 value and repeat step 1).
(5) Troubleshooting (Torque)
Adjustment Method
Set Pr. 824 a little lower and Pr. 825 a little higher. First lower Pr. 824 and check the motor for unusual vibration/noise and overcurrent. If the problem still persists, increase Pr. 825 .
Pr. 824
Decrease the value 10% by 10% until just before unusual noise and current are improved, and set about 0.8 to 0.9 of that value.
Note that a too low value will produce current ripples, causing the motor to generate sound synchronizing the cycle of current ripples.
Pr. 825
Increase the current value double by double until just before an unusual noise and current does not occur, and set about 0.8 to 0.9 of that value.
Note that taking a too long time will produce current ripples, causing the motor to generate sound synchronizing the cycle of current ripples.
Phenomenon Cause Countermeasures
1 Torque control is not exercised normally.
(1) The phase sequence of the motor or encoder wiring is wrong.
(1) Check the wiring. (Refer to page 14)
(2) The Pr. 800 Control method selection setting is improper.
(2) Check the Pr. 800 setting. (Refer to page 92) (3) The speed limit value is not
input.
(3) Set the speed limit value. (If the speed limit value is not input, the motor will not rotate since the speed limit value is regarded as 0Hz.)
(4) The torque command varies. (4)-1 Check that the command device gives a correct torque command.
(4)-2 Decrease Pr. 72 PWM frequency selection . (4)-3 Increase Pr. 826 Torque setting filter 1 (5) The torque command does not
match the inverter-recognized value.
(5) Recalibrate C16 Terminal 1 bias command (torque/
magnetic flux), C17 Terminal 1 bias (torque/magnetic flux), C18 Terminal 1 gain command (torque/magnetic flux), C19 Terminal 1 gain (torque/magnetic flux). (Refer to page 300) (6) Torque variation due to the
change in the motor temperature.
(6) Select magnetic flux observer by setting Pr. 95 Online auto tuning selection. (Refer to page 199)
2
When the torque command is small, the motor rotates in the direction opposite to the start signal.
The offset calibration of the torque command does not match.
Recalibrate C16 Terminal 1 bias command (torque/magnetic flux) and C17 Terminal 1 bias (torque/magnetic flux). (Refer to page 300)
3
Normal torque control cannot be exercised during acceleration/
deceleration.
The motor vibrates.
The speed limit is activated.
(When Pr. 807 = "0, 2", the speed limit may be activated since the speed limit value changes with the setting of the acceleration/
deceleration time in Pr. 7 and Pr. 8. )
Reduce the acceleration/deceleration time.
Or, set the acceleration/deceleration time to "0". (The speed limit during acceleration/deceleration depends on the speed limit during the constant speed.)
4
Output torque is not linear in response to the torque command.
Insufficient torque. Return the excitation ratio in Pr. 854 to the initial value.
♦Parameters referred to♦
Pr. 72 PWM frequency selection Refer to page 284
Pr. 178 to Pr. 189 (input terminal function selection) Refer to page 231 Pr. 800 Control method selection Refer to page 92
Pr. 807 Speed limit selection Refer to page 127
C16 to C19 (torque setting voltage (current) bias and gain) Refer to page 300