A Predictive Rotor Position Error Compensation Scheme for Enhanced PMVG Operation in Wind Turbine System Applications

This study proposes a predictive rotor position error compensation (RPEC) scheme for permanent magnet vernier generator (PMVG)-based wind turbine system (WTS) applications. The encoder-measured rotor position signal is prone to errors due to sensor degradation. Since PMVGs have a higher number of magnetic pole pairs, measurement errors in the mechanical rotor position lead to disorientation between the stator emf and current. Consequently, vector control efficacy and maximum power point operation are affected. To address this, predictive RPEC is introduced to ensure synchronization between the stator emf and the electrical equivalent of the measured rotor position. In this scheme, the nonzero d-axis emf resulting from rotor position measurement errors (RPMEs) is minimized by applying model-predictive increment/decrement error compensation to the encoder signals at each successive sampling instant. The proposed scheme is experimentally verified on a 5-kW PMVG-based WTS with the zero d-axis current vector control scheme.