Analysis of a Variable-Speed Synchronous Motor Drive Including Magnetic Saturation, Saliency, and Current Limit

Abstract

A method is presented for evaluation of the performance of a voltage-fed variable-speed synchronous motor drive. Special features include a treatment of magnetic saturation in a machine with rotor saliency and the incorporation of a current limit. Ranges of load angle and frequency, or speed, are covered and a variation of rotor excitation with speed can be included. The method of computer solution is described and examples are given and compared with measured results. The work is intended for use with drives having load angle control and is particularly relevant to cases having characteristics similar to those of d.c. series motors, in which high saturation occurs at low speeds.