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.