Hello Everyone,
I have developed PMSM controller with FOC algorithm. All control works fine and I have no problem with ramping, velocity control or PI tune.
That design is going to replace current one.
The problem is with voltage drop and current limit.
I supply it with 24V and current limit is 40A. When current goes above limit then voltage drops and controller restarts. It is normal, but I have to prevent from restart and even try to hold motor in position.
Normally reference controller takes up to 150A from battery and my controller is designed to do the same.
I have to add that restart prevent to my design, because that reference controller does it.
I have used oscilloscope to analize reference controller performance when current goes up to limit ( here : 40A):
Yellow – supply current, green – supply voltage
And also I have observed PWM control signal:
Yellow – PWM, violet – supply voltage, green – supply current
PWM in critical moment of drop:
And also Phase current:
Green – phase current, violet – supply voltage
On microcontroller I read:
1. A, B phase currents
2. Supply current
3. Supply voltage
4. Motor position – thanks to that I know velocity.
Maybe somebody had similar problem and found solution.
What should I do to prevent from restart?
SImply, how to hold motor on current limit.
Best regards,
Chris
I have developed PMSM controller with FOC algorithm. All control works fine and I have no problem with ramping, velocity control or PI tune.
That design is going to replace current one.
The problem is with voltage drop and current limit.
I supply it with 24V and current limit is 40A. When current goes above limit then voltage drops and controller restarts. It is normal, but I have to prevent from restart and even try to hold motor in position.
Normally reference controller takes up to 150A from battery and my controller is designed to do the same.
I have to add that restart prevent to my design, because that reference controller does it.
I have used oscilloscope to analize reference controller performance when current goes up to limit ( here : 40A):
Yellow – supply current, green – supply voltage
And also I have observed PWM control signal:
Yellow – PWM, violet – supply voltage, green – supply current
PWM in critical moment of drop:
And also Phase current:
Green – phase current, violet – supply voltage
On microcontroller I read:
1. A, B phase currents
2. Supply current
3. Supply voltage
4. Motor position – thanks to that I know velocity.
Maybe somebody had similar problem and found solution.
What should I do to prevent from restart?
SImply, how to hold motor on current limit.
Best regards,
Chris