Predictive Field Oriented Control based on MRAS Current Estimator for IM Drives

In this paper, a new Predictive Field Oriented Control (PFOC) strategy is presented for the alternating current machine drive. The key feature of the PFOC method is that it has no pulse width modulation (PWM) process and an optimized inner current controller. This scheme adopts an inner current loop with cost function and an outer speed loop for torque tracking. In the proposed PFOC method, we design an optimized inner current controller that the stator current components in stationary frame are compared with their reference values, and then the tracking errors are optimized in a sequential order. Therefore, the optimized controller has no tuning parameters to modify the two orthogonal objective terms in the cost function. Moreover, a MRAS current estimator is designed to realize high accuracy speed and current estimations. It is confirmed by experimental results that the proposed MRAS current estimator based PFOC achieves lower speed tracking error, as well as improved steady-state and dynamic performance.