Combined hysteresis current-controlled PWM inverter and robust control for a permanent-magnet synchronous motor

In this paper, a new combined control method is proposed for permanent-magnet synchronous (PMS) motors. The control system takes advantages of current hysteresis control and robust control. It is designed to focus on two objectives: (a) forcing the motor to track time-varying speed and torque trajectories; (b) keeping robustness in the situation of load torque uncertainty. The robust control part designs a nonlinear system based on the damping function version, and Lyapunov stability and average theory; besides, the current hysteresis control using the dq model through a park transform is applied to the inverter so that a near-sinusoidal AC output current can be obtained while satisfying the torque load or speed load requirements. The effectiveness of the proposed control is shown by computer simulations although the operating uncertainty.