Permanent Magnet Eddy Current Loss Measurement at Higher Frequency and Temperature Effects under Ideal Sinusoidal and Non-Sinusoidal External Magnetic Fields

Abstract

The eddy current in a conductive magnetic material is a common phenomenon of the electrical machines used in industrial applications. A permanent magnet electrical machine (PMSM) fed with an inverter consisting of higher-order frequency harmonics results in further increases of eddy current loss. The magnetic properties of the permanent magnet (PM) with and without higher harmonic content excitation signals are of great interest. Despite the popularity of PMSMs as higher efficiency motors in today's era, there are few doubts regarding the study of the magnetic properties of PMs with the loss measurement process. This paper addresses this problem and its solutions. The purpose of this paper is to describe the PM loss measurement method at higher frequencies and higher temperature effects under ideal sinusoidal and non-sinusoidal external magnetic fields. The ideal sinusoidal external magnetic field signal for measurement is generated using a frequency generator and linear power amplifiers. In contrast, the non-sinusoidal pulse with modulated (PWM) signal is generated using an inverter.