Investigation of Partial Demagnetization Faults in Permanent Magnet Synchronous Motors Based on Efficiency and Loss Maps Advanced Analysis

Demagnetization failure is a critical and prevalent fault in interior permanent magnet synchronous motors (IPMSMs), resulting from a variety of factors including thermal overheating, high electrical currents, and mechanical vibrations. Although the electromagnetic analysis and performance curves provides a deep insight into the machine behavior, it is not able to emulate the actual performance under various operating loads. To tackle these restrictions, advanced analytical tools such as efficiency maps are adopted to predict the behavior more accurately, which allows for enhanced performance monitoring. This paper aimed to incorporate electromagnetic analysis with efficiency maps to investigate the IPMSMs partial demagnetization fault, with emphasis on the magnetic flux residual density coefficient (Br) variations. The results indicated a significant degradation in the performance after exposure to the fault, with a 57% decrease in the generated torque, losses increased up to 35%, with a significant reduction in the range of high efficiency areas greater than 70% over the efficiency maps, and a deterioration in the efficiency especially at low speeds as the peak torque range is reduced. This study provides a comprehensive framework for evaluating the demagnetization faults effection, thus contributing to the elaboration of effective operation and maintenance strategies.