Suppression of Harmonics in DFIG based WECS using passive LCL filter

In the present day scenario, wind energy holds great importance as it is available in abundance, cheap to harvest and most significantly it is a non-polluting source of energy. Doubly Fed Induction Generators are employed chiefly for extraction of energy from wind flow as it makes the system more adaptable and reliable. However, due to presence of PWM converters in wind energy conversion system (WECS) employing DFIG, harmonics are injected in the system which is highly undesirable and causes reduction in power quality of the system. Hence, these harmonics need to be suppressed by use of suitably designed filter parameters. Now-a-days LCL-Filters are mostly preferred over L-Filters as its performance is superior for high power and low frequency applications. The proposed paper discusses a detailed systematic procedure for designing of LCL-filter used in DFIG based WECS. The paper also includes filter modeling and simulation through MATLAB/SIMULINK software using FFT analysis to verify the effectiveness of designed parameters of the LCL-filter under normal and fault conditions.