Research on Leading Angle Flux-weakening Control Strategy of Permanent Magnet Synchronous Motor Based on Over-modulation Algorithm

Abstract

To widen the speed range of PMSM, a new governing system combining leading angle flux-weakening control and SVPWM over-modulation is proposed in this paper. The inverter shifts to over-modulation state after the motor reaches the rated speed, thus the inverter fundamental output voltage amplitude is effectively increased. Then the inverter enters the flux-weakening control state, to maximize the speed range. Leading angle flux-weakening control uses three closed-loop control of speed, current and voltage, these three PI controllers work together to produce a current leading angle and current module, giving a quadrature-axis(q-axis) current and a direct-axis(d-axis) current. Simulation and experimental platform are established to verify the control system, both the simulation and experimental results proved the correctness and feasibility of the theoretical analysis.