Common Mode Voltage

Problem of electrical blast from VFD Harmonic; and a methodology for troubleshooting and increasing productivity

Abstract - VFD Harmonic forced a power plant to shutdown due to power quality failure. Starting with drive tripping it blasted switch gear, bus bar & electrical panel. This IPP with a 25mw, 11kV, 50Hz power plant and 5000TCD sugar milling unit had completed its first anniversary without harmonic problem. But during 2nd year's operation, it started-off with a massive blast of a 6300A Air Circuit Breaker (ACB). It was at the incomer of an electrical panel. The 415V PCC panel was supplying to sugar plant's process load.