Different Self Excitation Techniques for Slip Ring Self Excited Induction Generator

The paper discusses the different possible techniques to self excite the slip ring induction machine working as self excited induction generator. The generated voltage due to self excitation is initiated and sustained with constant value of power capacitors connected across the stator windings. Attention is focused on the influence of different techniques on generator voltage and output power capabilities. The generated voltage of the wind driven self – excited induction generator (SEIG) is mainly depending on the wind velocity fluctuations and load variations. By choosing the proper value of the self excitation capacitor banks achieves the reactive power requirements. In case of squirrel cage induction generator only the excitation capacitance at stator is used to achieve the reactive power requirements. But in case of slip ring induction generators with the different self excitation techniques at the rotor are used to achieve the reactive power requirements and improvement in the voltage build up. In previous literature there is no discussion about the different techniques of self excitation and its effects on the induction generator. These are the new methods proposed for the improvement in voltage build up and can also controls the slip. MATLAB/SIMULINK based work is carried out for 3.5kW machine. Proposed methods may be used for low cost variable speed wind energy conversion systems.