Single-phase inverter, STM32 output SPWM control IR2110, drive IRF250. DC input is 30V, and the output waveform is as shown in the figure below. 1. How does the distortion of the crest and trough cause and how to solve it? 2. Is the burr caused by the switch tube? How to filter out (if not adding filter circuit in the final output stage)
Stephen 发表于 November 23, 2020
The circuit does not seem to have any obvious faults. Looking at the drawings and markings, it should be a typical bipolar modulation PWM.
Looking at the top glitch, I feel that it is still driving the PWM problem. Is it true that the PWM waveform does not have the maximum and minimum limits when the positive and negative maximum values are reached. Generally speaking, the PWM must be limited. For example, for 8-bit PWM, the maximum cannot exceed 255 and the minimum must it's 1.
Also, are you measuring the P5 2-terminal waveform or just the 1-terminal waveform?
Nicolas 发表于 November 23, 2020
It should be that the drive is disturbed, check your loop design.
Spencer 发表于 November 23, 2020
Try connecting large capacitors to both p+ and GND. I think there are glitches in the P+ power supply. The glitches in the waveform are not just peaks and valleys.
