An optimized co-ordinated approach for harmonic minimization of Doubly Fed Induction Generator connected micro-grid system

This paper illustrates the biogeography based optimization (BBO) based selected harmonic elimination technique for DFIGs connected to a micro-grid. The lower order harmonics are individually eliminated in each DFIG outputs but the higher order harmonics are eliminated in such a way that the harmonics generated by one source is eliminated by the other after generating the same order of harmonics in opposite phase. The switching angles are computed off-line and stored in microcontroller memory in the form of look-up tables for on line application. The excitation power for the inverters is obtained from a photovoltaic (PV) panel. Proper simulations are executed for the proposed theory and subsequently supported by investigational verifications. Both the simulation and experiments agree well with the analytical formulation. The total harmonic distortion (THD) in the output is found to be within the stipulated limit.