Evaluation of High-Frequency Current Ringing Measurements for Insulation Health Monitoring in Electrical Machines

• Published in: IEEE transactions on energy conversion Vol. 37; no. 4; pp. 2637 - 2644
• Main Authors: Zanuso, Giovanni, Peretti, Luca
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Commutation; Condition monitoring; Current measurement; current ringing; Electric drives; Electrical Engineering; Elektro- och systemteknik; Evaluation; Frequency measurement; high-frequency measurements; Induction motors; Insulation; insulation state; Leakage current; Machinery condition monitoring; Monitoring; Stator windings; Stators; Switches
• ISSN: 0885-8969; 1558-0059; 1558-0059
• DOI: 10.1109/TEC.2022.3182364

Condition monitoring of the insulation health of electric machines is usually performed with offline tests. In recent years, online condition monitoring methods for the groundwall insulation have been introduced. The majority of these works are based on leakage current measurements, requiring additional equipment compared to the standard one in converters. The condition monitoring method in this work instead relies on the high-frequency ringing of stator currents occurring after a converter switching transition. This work evaluates the method experimentally in a randomly-wound stator winding of an induction machine prototype equipped with taps. The insulation condition change is forced by inserting external capacitors. Through the analysis of different metrics for the health monitoring and a detailed discussion of the hardware and software requirements for an electric drive, a viable way forward for the practical implementation of the approach is proposed.