Soft-Starter for High-Voltage IM Based on a Multi-Zone AC Voltage Regulator with Improved EMC

The simplicity and reliability of the operation of an induction motor (IM) play a fundamental role in wide practical application in production and in household appliances. A direct connection of a high-voltage motor to the network is characterized by a large inrush current and entails overheating, excessive wear of the motor windings and deep voltage dips in the network. In this article, we propose the study of a soft-starter for high-voltage IMs based on a multizone transistor AC voltage regulator (RAV) with improved electromagnetic compatibility (EMC) by analyzing electromagnetic processes. The paper presents the results of modeling electromagnetic processes during direct and smooth start-up, the dependence of the total harmonic distortion on the modulation depth, oscillograms of starting an induction motor, as well as recommendations for making a device layout.