Overvoltage limitation in variable speed drive with inverter

Abstract

Proposed mathematical model of variable speed drive controlled by the frequency converter. Computer model of non-linear system with changeable structure for simulation of limitation of capacitor overvoltages of DC bus of converter is elaborated. Proposed model of overvoltages limitation comprise high power resistance connected in parallel with filter capacitor. The non-linear regulator with hysteresis loop is applied to connect the resistance and discharge the capacitor. Simulation results of capacitor overvoltages and current across capacitor during starting are presented and discussed.