New Dynamic Self-Consistent Mathematical Model and Torque Characteristics of Permanent-Magnet Synchronous Motors with Magnetic Cross-Coupling

This paper proposes a new dynamic mathematical model of permanent-magnet synchronous motors (PMSMs) with magnetic cross-coupling and presents a new analysis of the torque characteristics of the motors. Generally speaking, dynamic mathematical models used for the design and analysis of PMSM control systems must consist of three basic equations that describe the main motor characteristics as an electrical circuit, torque generator, and electromechanical energy converter. In order to obtain reasonably compact models, some characteristics have to be approximated. However, in the case where the approximations used in the three basic equations are different from each other, the dynamic mathematical model often loses self-consistency and becomes self-contradictory. The proposed model, which takes the magnetic cross-coupling into account, is self-consistent and compact, and its effectiveness is validated by experimental data. Using the self-consistency and compactness, this study presents a new analysis of the torque characteristics of PMSMs, focusing on efficient torque generation. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(1): 42–55, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22382