How to use torque control?
Introduction
The torque control of a VFD is similar in implementation to the torque control of a servo drive. However, in terms of underlying principles, VFD uses open-loop control (by judging the magnitude of the output current), while servo drive uses closed-loop control (by judging the magnitude of the feedback current).
Operation
If you want to use torque control, you need to F0.00=0 first. Torque control needs to work in SVC mode.
Then, similar to the torque control mode of a servo, to ensure safety and avoid excessive speed when the load is suddenly reduced, which could cause runaway.
We need to set upper limiting frequency and lower frequency operating corresponding to F0.12 and F0.14.
The settings for VC and VB then differ, with VC offering more features.
For VB
The main relevant parameters are as follows:
| 3.09 | Speed/torque control | 0: Speed control 1. Torque control | 0 | ● | 0309 |
|---|---|---|---|---|---|
| F3.10 | Torque upper limit source in torque control | 0: Digital setting 1: AI1 2: AI2 3: Reserved 4: Reserved 5: Communication setting 6: MIN(AI1,AI2) 7: MAX(AI1,AI2) | 0 | ● | 030A |
| F3.11 | Digital setting of torque upper limit in torque control | -200.0% ~ 200.0% | 150.00% | ○ | 030B |
| F3.12 | Forward maximum frequency of torque control | 0.00Hz ~F0.10 | 50.00Hz | ○ | 030C |
| F3.13 | Reverse maximum frequency of torque control | 0.00Hz ~F0.10 | 50.00Hz | ○ | 030D |
For VC
The main relevant parameters are as follows:
| F3.46 | Speed/torque control mode | 0: Speed control 1: Torque control | 0 | ● | 0x032E |
|---|---|---|---|---|---|
| F3.47 | Torque given channel selection | 0: F3.48 is set 1: AI1╳F3.48 2: AI2╳F3.48 3: AI3╳F3.48 4: PUL╳F3.48 5: Keyboard potentiometer given ╳F7.01 6: RS485 communication given ╳F3.48 | 0 | ● | 0x032F |
| F3.48 | Torque keyboard numeric setting | 0 to 200.0% | 100.0% | ○ | 0x0330 |
| F3.49 | Torque direction selection | Units: Torque direction setting 0: The torque direction is positive 1: The torque direction is negative Tens place: torque reversing setting 0: Torque reversal is allowed 1: Torque reversal is prohibited | 00 | ○ | 0x0331 |
| F3.50 | Upper limit of output torque | F3.51 to 200.0% | 150.0% | ○ | 0x0332 |
| F3.51 | Lower limit of output torque | 0 to F3.50 | 0% | ○ | 0x0333 |
| F3.52 | Torque control forward speed limit selection | 0: F3.54 is set 1: AI1╳F3.54 2: AI2╳F3.54 3: AI3╳F3.54 4: PUL╳F3.54 5: Keyboard potentiometer given ╳F3.54 6: RS485 communication given ╳F3.54 | 0s | ○ | 0x0334 |
| F3.53 | Torque control reversal speed limit selection | 0: F3.55 is set 1: AI1╳F3.55 2: AI2╳F3.55 3: AI3╳F3.55 4: PUL╳F3.55 5: Keyboard potentiometer given ╳F3.55 6: RS485 communication given ╳F3.55 7: Purchase card | 0 | ○ | 0x0335 |
| F3.54 | Torque control positive maximum speed limit | 0.00 to upper limiting frequency | 50.00Hz | ○ | 0x0336 |
| F3.55 | Torque control reversal maximum speed limit | 0.00 to upper limiting frequency | 50.00Hz | ○ | 0x0337 |
| F3.56 | Speed/torque switching delay | 0.00 to 10.00s | 0.01s | ○ | 0x0338 |
| F3.57 | Torque acceleration time | 0.00 to 10.00s | 0.01s | ○ | 0x0339 |
| F3.58 | Torque deceleration time | 0.00 to 10.00s | 0.01s | ○ | 0x033A |