The research on residual voltage of asynchronous motors and its impact on power restoration

Abstract

The residual voltage of asynchronous motors after AC dump(RVACD) could have result in inrush current and inrush torque when asynchronous motors were reclosed or reswitched on the alternate power source, which would have cause damage to motors or bring power source problems such as mal-operation of feeder protection and voltage sag, etc. In this paper we built the space vector based model of motors to research the RVACD so as to thoroughly analyze the varying laws of electrical qualities and magnetic field after dumping, deduce the analytical expression of residual voltage of one motor, and get the solution for the group of asynchronous motors. The inrush current and torque are presented for power source to be restored at different moment after dumping.