Sensorless Direct Torque Control of Five-Phase Interior Permanent-Magnet Motor Drives

This paper presents the sensorless direct torque control (DTC) technique for five-phase interior permanent-magnet (IPM) motors. By using the introduced technique, fast torque response with low ripple in the stator flux and torque of the five-phase IPM can be achieved. Having 32 space voltage vectors provides a great flexibility in selecting the inverter switching states. Therefore, the stator flux and torque can be more precisely adjusted. Position information and speed are being estimated based on the position of the stator flux linkages. The mathematical model of the five-phase IPM motor is first derived. Later, the speed sensorless DTC method of the five-phase system is introduced. A five-phase IPM motor and a five-leg insulated-gate-bipolar-transistor-based inverter were designed and fabricated in the laboratory. The control method is implemented on a TMS320C32 digital signal processor board.