Tool/software:
Hi expert,
This is an urgent issue because my customer's project is pending at it.
When the chip triggers the watchdog reset, the pwm will not be pulled down instantaneously, and will continue to be high at 500us, resulting in the IGBT explosion of the PFC.
Repeating the experiment 50 times will result in one anomaly.
The key waveforms are as follows.
1.Entered the watchdog reset, during the reset, the main relay was pulled down to the ground, why is the PWM output still high level, not pulled to the ground.
Picture1/2:
Green: PFC control port - PWM waveform
Blue: waveforms at both ends of the rectifier bridge
Pink: PFC current waveform
Yellow: main relay waveform - GPIO port
2.Picture 3:
This is a relatively complete waveform diagram.
Green: PFC control port - PWM waveform; Blue: waveforms at both ends of the rectifier bridge; Pink: PFC current waveform; Yellow: Main relay waveform - GPIO port
3.Picture 4/5:
The control of the main relay is re-raised after resetting for 2ms
Green: PFC control port - PWM waveform; Blue: waveforms at both ends of the rectifier bridge; Pink: PFC current waveform; Yellow: Main relay waveform - GPIO port
4.Picture_6:
This is the waveform diagram of PWM oscillation
Green: PFC control port - PWM waveform; Blue: waveforms at both ends of the rectifier bridge; Pink: PFC current waveform; Yellow: Main relay waveform - GPIO port
5. Picture7
The following is the normal waveform, yellow is the chip reset port, and green is the PWM control port
6.Picture_8
The following is the waveform under normal conditions, yellow is the chip reset port, and green is the PWM control port (the PWM port is pulled down to the ground)
