Hello everyone,
I'am using focbox to control BLDC pump with FOC mode. I'am working with VESC TOOL 0.95, FOCBOX firmware: 3.40, hardware 410.
My project is to control BLDC pump from 0-10bar pressure in the sensorless mode because pump doesn't have any sensor. It's just BLDC three phase pump (3-poles). The RPM of the pump at 10bar must be 6000rpm(18000ERPM).
To changing pumps RPM I'am using ADC potentiometer with Duty Cycle mode (changing RPMs from 0 to 6000).
I need an open loop for the whole area of pumps speed not just at 6000RPM. At 6000RPM and 10bars pump speed is decreased for only 200RPM and that is good for me. The problem is when I set potentiometer to the half of his area and put a load(water) to the pump, pump speed is decreased too much(2000RPM).
I want that the speed is same just current is increased. I was trying to change Speed Tracker Kp, Ki parameters in the Advanced window of FOC mode, but no success. So, my pump have always be in openloop from 0 to 6000RPM independently of load on the pump.
Which parameters i have to tweak?
Thank you very much
First of all, you might want to switch to the VESC 6 since the HW 4.10 has only 2 shunts and can't measure the current accurately. In between 60 and 80% duty the current will decrease and from 80 to 100% duty cycle the current will almost jump. Not ideal to accurately control a pump! If thing don't work as desired, you now know why.
PID Speed Control might be what you are looking for. That will try to maintain the speed of the pump at the desired level. It is also used for the Cruise Control on skateboards and cars.