Performance Analysis of Vector-Controlled Interior Permanent Magnet Synchronous Motors Based on an Accurate Dynamic Model

Recent research suggests that Permanent Magnet Synchronous Motors (PMSM) may emerge as a formidable competitor to Induction Motors (IM) in high-performance servo applications. The literature extensively uses the simple lumped-parameters model "LPM", also known as the lumped-parameters dqo model or conventional model, to depict the dynamic response of the machine using Park and Clarke transformations. The notion of vector control is applied to PMSM to provide linear dynamics similar to those of a DC motor. The linearized model contains two control loops: the current loop and the speed loop. The control scheme aims to trace the specified reference speed accurately while having a quick dynamic reaction. This has been achieved in various literature along with different enhancements. However, due to the linearized lumped-parameters model and its assumption of constant parameters, the control system's accuracy and dynamic performance can be affected. This paper aims to study the effect of accurate physical motor modeling (in terms of the degree of complexity) on the dynamic response of the vector controller. The industry-standard Finite Element Method (FEM) is used in the modeling method, and its simulation results under vector control are compared with those of conventionally modeled motors. The simulation results show that the proposed model has successfully introduced a more realistic response to the machine's dynamic performance under vector control compared with conventional model performance, especially with torque and back-emf responses.