I am using the VESC Tool to configure my Maytech VESC. Hardware 4.12 and firmware 3.40. I am using a 3S LiPo battery. The motor is Velineon 3500, used in 1/10th scale Traxxas RC car.
These are my BLDC Sensorless settings:
- Startup boost: 0.1
- Cycle Integrator Limit: 39.5
- Min ERPM: 200
- Min ERPM Integrator: 800
- BEMF Coupling: 450
The 'BEMF coupling' and 'Cycle Integrator Limit' values were determined using "Detect BLDC Parameters" functionality of the VESC tool.
When I apply a duty cycle of 0.2 the motor jerks back and forth and does not rotate smoothly. Setting the BEMF coupling to 100 fixes this issue and the motor runs at about 9000 ERPM with a duty cycle of 0.2. But then why does the VESC tool detect the same parameter as 450? What is the consequence of setting a low BEMF?
Now I try PID control with BEMF Coupling set to 100, Ki = 0.0001 and Kp = Kd = 0. When I set the speed to 3000 ERPM the motor jerks back and forth and does not rotate smoothly. The current also peaks to the max limit that I have set (30 A). What could be wrong with the VESC configuration?