Design Procedure and Optimal Guidelines for Overall Enhancement of Steady-State and Transient Performances of Line Start Permanent Magnet Motors

摘要

This paper proposes a design procedure in addition to some optimal design guidelines for line start permanent magnet (LSPM) motors, independent from their ratings. Major transient and steady-state characteristics of LSPM motors, including magnet braking torque, synchronizing torque, efficiency, and power factor, are analyzed with respect to the main motor design parameters, i.e., motor back electromotive force, reactances, and saliency ratio. The contradicting behaviors of the motor characteristics with respect to the motor parameters are fully investigated. Design guidelines are developed to wisely compromise the performance characteristics by selecting optimal parameters. A design procedure considering the guidelines is proposed. By following the procedure and guidelines, an LSPM motor is designed and optimal values of the motor parameters are determined. Accordingly, a prototype LSPM motor is built and tested. The finite element method (FEM)-based simulation results in close agreement with the experimental results confirm superior steady-state and transient performance characteristics of the motor, thus validating the developed guidelines and the proposed design procedure.