Control of a Self-excited Squirrel Cage Induction Machine based Wind Energy Conversion System Operating in Both Stand Alone and Grid Connected Modes

This paper presents the controller design of a wind energy conversion system built around a self-excited squirrel cage induction machine that can be operated in both standalone and grid connected modes. The control scheme regulates the machine terminal voltage in the standalone mode and the grid side reactive power in the grid connected mode. Both a TCR type SVC and a VSI based STATCOM are employed as flexible reactive power sources. The overall control scheme has been developed and verified in MATLAB/SIMULINK platform. The power versus terminal voltage characteristics, the terminal voltage, system frequency and reactive power versus various load levels in different modes of operation are discussed.