Protection circuit for permanent magnet synchronous motor in field weakening operation

摘要

A safety circuit for providing protection against failures that impact safety of an inverter circuit driving a Permanent Magnet Synchronous Motor (PMSM) including high and low side switches connected in a bridge and driven by a gate driver circuit during operation of the PMSM in a field weakening mode, the gate driver circuit including stages for driving the high and low side switches, the safety circuit comprising a main power supply and a back-up power supply for supplying voltage to the gate driver circuit driving the switches of the bridge of the inverter circuit, wherein if the main power supply fails to deliver adequate power to the gate driver circuit, the back-up power supply provides power to the gate driver circuit to allow the gate driver circuit to turn ON the low side switches and turn OFF the high side switches.