Impact of Permanent Magnets Demagnetization on Line-Start Permanent Magnet Synchronous Motors: Feasibility Study of Protection for Mains and Inverter Operation

This paper investigates the impact of permanent magnet (PMs) demagnetization on line-start permanent magnet synchronous motors (LSPMSMs) under mains and inverter operation, focusing on protection strategies for hazardous environments. Demagnetization can severely affect safety, stability and efficiency introducing significant risks. By identifying critical operational points - rated load, overload fault, and start-up conditions, this research outlines a qualification program for compliance with explosion protection standards. Experimental methods analyze faults like asynchronous operation due to overload or demagnetization, providing a framework for effective protection strategies and ensuring safe operation in compliance with international standards.