Self-Sensing Six-Phase PMSM Drive Based on Back-EMF Measurement

Abstract

This paper presents a novel procedure for the emergency sensorless operation of a six-phase electric drive. More degrees of freedom provided by multiphase technology have been utilized to determine the rotor flux position. The proposed technique is based on the direct measurement of the back EMF generated on a disconnected three-phase winding of a six-phase permanent-magnet synchronous machine (PMSM). The method is suitable for the emergency operation of an electric drive in the case of speed/position sensor failure. The proposed solution has been verified utilizing a six-phase permanent-magnet synchronous machine with a displacement of 30° between two three-phase sets of the stator winding and a power of 1 kW.

Keywords

• back-EMF measurement
• multiphase machines
• permanent-magnet machines
• sensorless control
• six-phase machines