X-NUCLEO-IHM07M1 can not drive l6230 through input PWM to obtain normal and stable voltage due to overcurrent protection

[Neal]

Hello,

I have a X-NUCLEO-IHM07M1 suite. When I used this hardware and the FOC algorithm(PWM frequency is 8kHz) to drive a BLDC motor. Then I found that the overcurrent protection was always triggered, but I didn't know why it was triggered and how to solve it. Can someone help me?

In my control algorithm I am using only the next pins of L6230 chip:

- EN1, EN2 and EN3 (for enable the whole bridge),

- IN1, IN2, and IN3 (on that pins I generate PWM signals, without dead time),

- 3 pins for reading currents

Although the motor can rotate, it has the strong vibration and the l6230 chip is seriously hot, as the same in this problem community.st.com/s/feed/0D50X0000AeXo70SQC

I use 24V DC input. Here are three oscilloscope waveforms.

In the first figure, yellow waveform is a PWM input of the l6230, and the blue waveform is the out1 output, It is obvious that the out1 output is discontinuous.

The second is a magnified version of the first picture.

The third figure shows that the yellow waveform is the waveform of the DIGA-EN pin, and the blue waveform is still the out1 output.

Kind regards,

Neal

[Neal · Accepted solution]

The reason is that I use a small internal resistance aircraft model motor. The internal resistance is only 0.05 ohm, so the over-current occurs as soon as PWM is turned on. The official original PTZ motor has an internal resistance of nearly 10 ohm, so it will not over-current. To sum up, the motor selection is inappropriate. The l6230 is not suitable for driving aircraft model motors with small internal resistance.