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Modeling and analysis of self-excited induction generator for wind energy conversion

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Abstract

Self-Excited Induction Generators (SEIG) have recently emerged for wind energy conversion in remote and rural areas due to many advantages as standalone induction generator over Grid Connected Induction Generators. However, poor voltage and frequency regulation under varying load and speed is the prime disadvantage of standalone SEIG. Steady state analysis for such machines is important to understand their behavior under varying operating conditions. This paper presents a detailed d-q model of SEIG using Matlab/Simulink which contributes to the development of SEIG modeling with a limited complexity. From the generalized d-q model, the effect of different constraints such as, variation of prime mover speed, and excitation capacitor size, on the SEIG output built up process have been addressed and analyzed. The variation of the magnetizing inductance and the non-linearity is also considered.

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... Among the most common generations systems, WECS are increasingly becoming more cost competitive compared to all the environmentally safe and clean renewable energy source. Fixed speed WECS have gained much popularity among the manufacturers and developers in this field mainly due to the fact that this system uses a squirrel cage induction generator [5]. The design of larger wind turbines and reliability requirements match the features of multiphase machines due to their capability to split power and provide fault tolerance. ...
... SEIG can cope with a small increase in speed from their rated value because, due to saturation, the increasing rate of the generated voltage is not linear with the mechanical speed [7]. Understanding the voltage terminal build up process of SEIG and its performance under steady state and dynamic condition, it becomes a crucial issue toward the development of more efficient and competitive SEIG technology [5], [7]. For an SEIG, the external elements that can modify the voltage profile are the mechanical speed, the terminal capacitance and the connected load impedance [8], [9]. ...
... Also rotor voltage is expressed by equation = + j + j + " (6) [14] III. RESEARCH METHODOLOGY A real time prototype is made using asynchronous machine as IG and DC shunt motor as prime mover for the analysis purpose in laboratory. ...
... But, it suffers from the regular maintenance of the gearbox and the high cost of capacitor-bank required for the excitation. Besides, SEIG has poor voltage and frequency regulations, where it depends on excitation capacitance and prime mover speed [6], [7]. Moreover, DFIG is widely utilized in largescale WTGS due to its lower converter costs and lower power losses. ...
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