A non-cascade predictive speed and current controller with PWM modulation for PMSM

This paper presents a PWM predictive speed and current (PPSC) controller for PMSM drive. The main contribution of this controller is that speed and current controllers are combined together to substitute conventional cascade PI structure, and such non-cascade controller largely improves system dynamic performance. The number of state variables and length of prediction horizon are largely reduced compared with other non-cascade predictive controllers, so that the computation complexity is small which leads to PPSC more feasible in practical application. Moreover, to solve the problem that q-axis current reference cannot be obtained directly, this paper adopts estimated load torque to resolve it. Furthermore, a novel approach to constrain currents and voltages is proposed. Effectiveness of the PPSC controller is verified through experiments on a 750W PMSM.