LQR Control of Permanent Magnet Synchronous Motor Based on Exact State Feedback Linearization

Permanent magnet synchronous motor (PMSM) is a typical nonlinear system with significant coupling. This paper proposes a linear quadratic regulator (LQR) to control the PMSM with exact state feedback linearization. Based on the mathematical model of PMSM, the corresponding affine nonlinear system is constructed and the exact linearization conditions are discussed using differential geometry theory. Applying appropriate coordinate transformation and state feedback transformation, the affine nonlinear model is linearized into a linear system. Then, an optimal controller is designed to control the decoupled linear plant with LQR. Simulations and experiments are performed to verify the effectiveness of the proposed control strategy. The results demonstrate the feasibility of the differential geometry method and reveal the high performance and advantages of the proposed nonlinear controller in dynamic response and steady-stage error regulating characteristics.