Gimbal motor losing control

developement
1

Hi, I was testing my new control board with 2804gimbal motor(12N14P, 7R Resistant) when i discovered something wrong with it.

Configuration of the board is as below:
MCU LGT8F328P(similar to atmega 328p)
Driver Drv8313
Magnet Encoder AS5600

Under voltage control mode, the max velocity of the motor is around 50 rad/s. Current is 0.3A when the velocity is 40rad/s. However when the velocity increse, the current goes straight up to 1.5A and reach the max velocity 50rad/s.
What’s even worse is that, under voltage position control mode, if given a velocity excitation(higher than 80 rad/s), the motor will lose control and spins at 180 rad/s.

I suppose the phenomenon above is concerned with the shortage of voltage control.That is, when the velocity is higher, because of the BEMF, the assumption of Vd=0 does not hold anymore. Vq calculated by the foc algorithm cannot correctly drive the motor. Is that right?
If as I suppose, is there a way to fix Vq by taking BEMF into consideration under voltage mode? or any
other method to avoid losing contorl after excitation?

Thanks!

2

I had a similar problem with my gimbal motors being capped at a lower speed than rated. I solved it by increasing the driver.voltage_limit and changing from the i2c as5600 encoder to the spi As5047. Hope it helps