Estimation of PMSM magnetic saliency using injection technique

Abstract

The permanent magnet synchronous motor (PMSM) has very attractive properties such as: high dynamics, small size, high efficiency, low maintenance, small size and mass to power ratio, which make it suitable for the use in industrial drives. In particular its higher efficiency means that PMSM may be used in applications where the energy savings compensate the higher initial cost. For the best utilization of PMSM properties is very important to use some of modern control techniques. But the techniques require information about rotor position. Rotor position measurement is performed using sensors that are expensive and mainly reduce the reliability of the drive. This fact is the reason for interest in sensorless control techniques. In the article, emphasis is placed on sensorless control of PMSM using voltage signal injection, which requires magnetic saliency of the machine. Magnetic saliency and machine suitability for sensorless control using injection methods can be determined in advance using a measurement method whose mathematical analysis is presented in the article. The measurement method was simulated using software product Matlab-Simulink and experimentally verified on a laboratory stand with the AC drive.