A novel position sensorless control scheme for doubly fed reluctance motor drives

A novel position sensorless control algorithm for the newly developed doubly fed reluctance motor (DFPM) drives is presented. The control makes use of the 60-Hz terminal variables, which are easy to acquire and process, for estimation and control of the torque angle of the machine, while the speed of the system is given in an open-loop mode. The control is robust and suitable for variable-speed pump-type application. With this control, the required VA ratings of the PWM converter are only 50% of that of the DFRM motor, and the motor can be started with full load torque. This control scheme has been successfully implemented on a 2-hp DFRM drive.