A PMSM speed servo system based on internal model control with extended state observer

The internal model control (IMC) has been widely used for its simple structure, but its control performance has a relationship with the filter order and time constant directly, so that its disturbance rejection performance is influenced in the permanent magnet synchronous motor (PMSM) drive system. An IMC with extended state observer (ESO) is proposed in this paper. Based on the mechanism of IMC and the mathematical model of PMSM, the first order and second order internal model controllers are designed. Then, the design method of dynamic compensation using ESO for PMSM is presented, and the novel internal model controller with ESO is realized. Simulation and experimental results show that the proposed control strategy can reduce the influence of external torque disturbance and moment of inertia variation on the performance of the system. And the effectiveness of IMC with ESO is verified.