Comparisons of four rotor speed identification schemes for PMSG based WECS

This paper implements and compares four speed identification schemes for Permanent Magnetic Synchronous Generator (PMSG) based direct driven Wind Energy Conversion System (WECS). The application issues and the performance of different schemes are discussed in details. The identification accuracy, algorithm complexity and parameter dependency of those schemes are compared by simulation and experimental studies in the paper, as well as their influence on the operation performance of the WECS. As indicated by the paper, the strategy with the back EMF Phase-Locked Loop (EPLL) is suitable for industrial application due to its simplification and effectiveness. The Flux Integration Algorithm (FIA) performs similarly with EPLL but is most complex. The Voltage Phase-Locked Loop (VPLL) based strategy requires more parameters than other schemes and its performance is worse than EPLL and FIA. Although the Simplified Kalman Observer (SKO) based strategy is simplest, the system performance is worst in the four strategies. The simulation and experiment verify the comparative analysis and the conclusions.