Sensorless Control of a Four Phase Switched Reluctance Machine with Novel Bridge Converter

This paper presents a method of position and speed estimation technique for a four-phase switched reluctance machine with novel bridge converter. The phase inductance is measured by high frequency voltage injection in an idle phase which is opposite to energized phase and the inductance variation is maximum. The two order Fourier series is used to match the phase inductance with rotor position. The freewheeling process has been considered during communication, and continuous rotor position can be obtained. PWM double closed loop control is implemented in energized phase. Experimental results demonstrate the effectiveness of proposed method for continuous rotor position estimation and the machine can achieve high performance sensorless control. Furthermore, the effect of mutual inductance and back-EMF on rotor position estimation is analyzed.