Modeling and dynamic analysis of gearless variable-speed permanent magnet synchronous generator based wind energy conversion system

Abstract

This paper investigates the dynamic behavior of a gearless variable-speed Wind Energy Conversion System (WECS) based on Permanent Magnet Synchronous Generator (PMSG). Models and equation that describe different components of the WECS are addressed and their implementations into PSCAD/EMTDC are described. The control system of the back to back converters is developed for capturing the maximum energy from varying wind speed, regulating the DC-link voltage at a constant value, and maintaining reactive power generation at a pre-determined level which is zero in this study. Moreover, the pitch-angle controller is designed to regulate the machine speed at its rated value for high wind velocities. Simulation is performed in PSCAD/EMTDC software to evaluate the performance of different controllers and to study the dynamic behavior of the gearless WECS under varying wind speeds. This modeling study can be used for evaluating the control scheme, dynamic performance and impacts of a variable-speed WECS on the electrical grids.