Series Multi-level Unit High Voltage Converter on the Protection of Grounding

Motor-phase-to-ground is a common fault.High voltage converter output voltage with the high harmonic components,motor winding single-phase ground will easily be damaged insulation,so the high voltage converter must be equipped with single-phase-to-ground protection.Different principle of frequency converters,the grounding protection and the principle are not the same.A modular multi-level series of high voltage converter voltage protection was taken as an example of the grounding of the high-voltage converter grounding protection analysis to explore.Through the experiment,the characteristic wave was obtained,and the respondence viewpoint of the protection constitution and fixed value setting were proposed.