Novel anti-windup of a current regulator of a surface-mounted permanent-magnet motor for flux-weakening control

This paper describes a novel anti-windup method of current regulator of surface-mounted permanent-magnet synchronous motors for flux-weakening operation. It is implemented in the synchronous-frame PI current regulator with space vector PWM. The difference of q-axis voltage between the regulator output voltage and the saturated voltage is used for flux-weakening control by modifying d-axis current reference. With this method, the anti-windup control and the flux-weakening can be achieved simultaneously. It can be easily implemented in software, and no additional hardware or sensor is needed. Moreover it guarantees more output torque than the conventional anti-windup and flux-weakening method does by better utilizing dc link voltage. The effectiveness of this method is proved by computer simulations and experimental results.