The phenomenon of switching overvoltage in electric drives based on highspeed switches, problem statement and review of its solution options

Abstract

The article considers the problem of voltage overshoots at motor terminals in electric drives which use high-speed semiconductor devices (in particular SiC-MOSFET and GaN transistors) in its invertors. It is shown that the use of wide band gap semiconductors allows to significantly increase the frequency of pulse-width modulation, improve the dynamic properties of the inverter and reduce the size of the converter itself. At the same time, the high switching speed produces overvoltage at the motor terminals and uneven voltage distributions across stator windings due to high rate of voltage change over time ( dv dt / ), which causes accelerated aging of the insulation and can lead to premature failure of the electric machine. A review of the main approaches to reducing or preventing the manifestation of this phenomenon is carried out, including: the use of sinusoidal and RLC filters of various topologies, the main purpose of which is to match the wave parameters of the cable with its load (motor), the use of multilevel inverters, as well as specialized circuits with diodes to limit the overvoltage level. The results of the work can be used to help with the design of modern high dynamic electric drives