Robust Sliding Mode Current Controller for IPMSM Drives With MTPA Strategy

In this paper, robust current and speed control loops are designed for interior permanent magnet synchronous motor (IPMSM). The speed loop is designed using conventional PI controller with a novel maximum torque per ampere (MTPA) algorithm to generate two axis stator current reference for maximum efficiency. A single variable is used to represent machine all uncertain parameter which is stored in a single look up table to speed up execution time and saving system memory. In current loop, 2nd order nonlinear sliding mode control is employed to reduce the effect of disturbance, nonlinearities, chattering problem and to increase robustness against parameter variation under different condition. Simulation result shows the effectiveness of proposed controller applied in both speed and current loop. Sliding mode current control with MTPA effectively reduces the effect of machine modeling error and parameter uncertainty.