A problem when building an inverter from DC to AC

[naxingyu]

We discovered a problem when building an inventor from DC to AC. When the IGBT module was working at 15kw and the voltage of the DC power supply was 650V to 700V, the 5V and 3.3V power supply for the control chips fluctuated significantly, causing the chip to restart. We suspected that it might be caused by electromagnetic interference. We tried grounding, adding filters, and other measures but it didn't work. What is the possible cause and how to solve this problem?

 

[KlausST]

Hi,

probably a PCB layout and/or wiring problem.

Schematic as well as PCB layout is essential for finding out the root cause.

Klaus

 

[barry]

Also identifying what your picture show would be good and what the conditions are.
And, those are way more than ‘fluctuations’,

 

[FvM]

Presume that the voltage waveforms are not showing the real supply voltage but the voltage that arrive at oscilloscope input, measured voltage + common mode noise. It may even be that oscilloscope ground connection is the final reason for controller reset.

The increasing noise level in the waveform suggests a state change in your inverter, e.g. rising output current. There's obviously a problem of inverter switching current/voltage coupling into your control circuit or at least the measurement setup.

I agree with previous contributors that we need to look at schematic and layout details to understand possible coupling pathes.

 

[thannara123]

In between the microcontroller power supply should have an enough capacitor to withstand or supply the dc to the controller .
Do you have it ?