A Position Sensorless Startup Method for DSEM Based on Pulse Injection

This paper proposes a startup method for doubly salient electro-magnetic motor (DSEM) based on H-bridge converter. Firstly, the influence between three-phase currents and excitation current under the drive of H-bridge converter is analyzed. Then, a pulse injection-based method is proposed to estimate the position during the startup process by comparing the magnitude of the response current. This method fully utilizes the falling edge of the acceleration pulse, with only one test pulse injected to obtain the self-inductance relationship, it reduces the number of test pulse injections, thus improving the startup performance. Moreover, this method avoids the influence between three-phase currents and excitation current, and it does not depend on the accuracy of the previous position estimation. The injected test current does not generate negative torque. Finally, the feasibility and correctness of this method are verified through an 18/12 pole DSEM experimental platform.

I. Introduction

The doubly salient electro-magnetic motor (DSEM) has the characteristics of simple structure, flexible control and high reliability, which is suitable for operation at high temperature and speed, and has attached widespread attention in the fields of aerospace and electric vehicles [1]. The operation of DSEM requires position signals. Traditionally, DSEM relies on mechanical position sensors to provide position signals, which have the disadvantages of large volume and low reliability. Therefore, it is significant to realize position sensorless control.