PWM High Speed Block. How to manage the output
sorry for another post but I have another issue in my project of motor control.
I use the PWM High Speed Block to generate 6 pulses for a three phase inverter. I have set complementary PWM with a dead time of 2e-06s and a switching frequency of 10kHz.
The problem arises when I force the three duty cycles to 0 (i.e. to turn off all the IGBTs and to stop the motor).
I would like to have all the 6 IGBTs turned off in this situation, i.e. having the 6 PWM outputs all to 0.
But, phsically measuring the dsPIC PWM pins I see:
- The three PWM_H are 0
- The three PWM_L are 1 with a pulse to 0 for the duration of the dead time (see picture of the oscilloscope)
I think that this situation is consistent with the complementary logic of PWM and the motor physically stops but, it is not very safe. I would like to have all the six pulses at 0 when I stop the motor for safety reasons.
Is there the possibility to force all the six output to 0?
Thank you for your precious support.