Different Self Excitation Techniques for Slip Ring Self Excited Induction Generator

Abstract

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.

Investigation of an Induction Wound Rotor Motor to Work as a Synchronous Generator

“…As shown from the model in Figure 2 and Figure 4(c), the rotor circuit includes just two phases. This scheme of connection induced more magnetomotive force than the three phase connection [8,9].…”

Comparative study of ultrahigh-speed induction generators with self-excitation

“…The simplest way is to connect fixed condensers to the terminals of the machine which generates capacitive reactive power [10]. At a constant stator frequency the magnetizing current is a nonlinear function of the stator voltage due to saturation, while the condenser current vs. stator voltage is a straight line (Fig.1).…”

Utilizing a Permanent-Magnet Alternator With the Full Converter in Wind Turbine Increases the Efficiency of Supplying an Active and Reactive Power to the Electrical Network

“…the use of wind energy to produce electricity) for several reasons; including increasing concerns about the pollution of the environment and the warming of the globe, keep energy production safe, and provide jobs. There are a large number of advanced technologies to manufacture different types of wind turbines, which in turn compete for a larger share in the market for this booming industry [3].…”

“…The generated voltage of the wind driven, selfexcited 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 [3]. A combination of series and parallel capacitors are used to excite the induction generator while operating at variable speeds [4].…”