Method and system for reduced voltage start-up of AC motors in multi-motor system

摘要

A method and system that provides for simultaneous or independent start-up of two or more three-phase AC motors with reduced starting current. Two AC motors have their stator windings connected in series across the power network. If more than two AC motors are to be started, the stator windings of the additional motors are connected in parallel with the stator windings of one or both of the first two motors and the phase leads of the additional motors are connected to the power network. The voltage result vector is less than the sum of the rated voltage of each motor. After a preset time delay or when the motors reach a certain speed, the rated voltage is applied to each motor by disconnecting the stator windings from the series connection and connecting the stator windings of each motor in a delta configuration.