A Method for Efficiency Determination of Permanent Magnet Synchronous Motor

Abstract

The utilization rate of permanent magnet synchronous motors (PMSM) is increasing in the industry today. Due to this fact, the high efficiency ratio of PMSMs has reached IE5 premium class efficiency. Therefore, the efficiency coefficient of the PMSM varies from 92% to 97%. As a result, this type of motor is replacing traditional asynchronous motor by falling into efficiency classes of IE1, IE2, IE3, and IE4, which range from 75% to 92% in the industry. Thus, the object of the research was to develop a method to determine the efficiency of permanent magnet synchronous motor applications in order to identify and verify the variating parameters. In this study, an innovative and safe method of PMSM testing when the nominal parameters of the motor are unknown was presented through research. Also, the comparison of PMSM oscillograms with different types of load types and phase shift oscillograms, generated using operation amplifier, were analyzed and is scrutinized. During the design process, the PMSM was projected for the IE5 premium efficiency class. However, after production, the PMSM sometimes does not match the nameplate parameters, which are declared by the factory. As a result, during the testing procedures, the PMSM nameplate parameters did not match the projected parameters. Facing the problem of the projected and tested efficiency mismatch, the PMSM highest efficiency determination experiments were performed in a laboratory in order to prove the highest efficiency of the PMSM. The results showed different PMSM input parameters. Furthermore, the experimental results of the PMSM testing were confirmed with electrical machines theory, and simulation results were performed with electrical circuits. The theory of PMSM operating in different values of input voltage is represented in graphical abstract.