A way to start an induction motor during a change in the voltage phase on one of two stator windings

Abstract

The possibilities of starting an induction motor during a change in the voltage phase on one of two stator windings are considered. In spite of the existing variety of ways to start ac machinery (direct, impedance, by means of frequency converters, soft-start devices, and additional low-power electric drivers), starting high-power drivers is still an important issue in electrical power engineering, as the impellent load is sensitive to the parameters of quality of electric power and itself affects the supply mains. This problem is especially urgent for industrial power supply with weak external connections with power supplies. High-power induction motors often have two stator windings that are intended to be connected to the circuit with different voltages. Experimental results with the use of a physical model allowed a new way to be developed of soft starting of AN induction motor with two stator windings. The method is based on a change in the angle of voltage phase of the second winding in respect to the basic (first) motor winding.