Output power maximization of IPMSM using overmodulation region of direct torque control system

This paper proposes an interior permanent magnet synchronous motor drive system based on direct torque control of the overmodulation region of an inverter. It is important to operate in the overmodulation region to maximize the motor output power. An overmodulation pulse width modulation (PWM) drive and a square-wave drive are used for high-power operation because of the high voltage utilization of the inverter. The proposed system performs amplitude compensation for an overmodulation PWM drive, terminal voltage estimation for a square-wave drive, and selection of these drives. The effectiveness of the proposed system is experimentally demonstrated.