New non-linear d-axis current controller for permanent magnet synchronous motor based on adaptive correction factor

In the vector control of a permanent magnet synchronous motor (PMSM), the adequate control of the d-axis stator current component is important to achieve an efficient energy consume, and to increase the speed above the nominal value through flux-weakening method. This paper presents a simple a non-linear d-axis current controller which uses the mechanical speed, the q-axis stator current and a correction factor that depends on the d-axis current error. Simulation results show the performance of the proposed system and its robustness against variations of the nominal parameters of the motor.