An Advanced Speed Control Scheme for IPM Based Synchronous Generator

Abstract

This paper proposes a direct control strategy for an interior permanent magnet synchronous generator-based variable speed wind turbine by using fuzzy logic. In this scheme, the requirement of the continuous rotor position is eliminated as all the calculations are done in the stator reference frame. This scheme possesses advantages such as lesser parameter dependence and reduced number of controllers compared with the traditional indirect vector control scheme. Fuzzy logic adds to bivalent logic an important capability—a capability to reason precisely with imperfect information. Imperfect information is information which in one or more respects is imprecise, uncertain, incomplete, unreliable, vague or partially true. In fuzzy logic, results of reasoning are expected to be provably valid, or p-valid for short. The direct control scheme is simpler and can eliminate some of the drawbacks of traditional indirect vector control scheme. The proposed control scheme is implemented in MATLAB/ Sim Power Systems and the results show that the controller can operate under constant and varying wind speeds. Finally, a sensor less speed estimator is implemented, which enables the wind turbine to operate without the mechanical speed sensor. The simulation and experimental results for the sensor-less speed estimator are presented.
Keywords: Direct control; interior permanent
magnet (IPM) synchronous generator; sensor-less speed estimator; variable speed wind turbine; Fuzzy logic Controller