Sliding Mode Flux Observer Based Predictive Field Oriented Control for Induction Machine Drives

This paper presents a robustness Predictive Field Oriented Controller (PFOC) with a rotor-flux based sliding mode (SM) observer. Similar to FOC, the proposed PFOC compares stator current in orthogonal frame with their reference values. The main contribution of PFOC is that it has the merits of unconstrained bandwidth of inner loop and bypassing the modulation stage, to guarantee fast dynamic response. More specifically, the tracking error terms of orthogonal control objectives are optimized in a sequential order, to provide a solution for weighting parameter tuning according to the different operating conditions. Furthermore, a rotor-flux based SM observer is used to estimate rotor flux and speed. Experimental results confirm that the proposed controller with the SM flux-based observer performs well at steady and transient state, as well as high speed estimation accuracy at a low speed.