Overvoltage protection for interior permanent magnet synchronous motor testbench

This paper considers the protection circuit for the traction interior permanent magnet synchronous motor (IPMSM). Field weakening operation of that type of electrical machine require continuous control of the demagnetization current. In case of some fault in the control or power converter the back-EMF of the motor increases and the generation to the DC link of the inverter occur. This may lead to the inverter breakdown due to overvoltage. One of the possible solution is to build a protection circuit that shorts all phases of the motor together in case of overvoltage occurs. This paper aims to build a fast response overvoltage protecting circuit for traction IPMSM. The simulation results are shown and proved the excellent effectiveness of this circuit.