Multiple Complex Coefficient Filter ISOGI-QSG based control for Grid Connected SPV System

Abstract

A three-phase single stage grid integrated solar PV system with Multiple Complex Coefficient Filter Improved Second Order Generalized Integrator Quadrature Signal Generator(MCCF ISOGI-QSG) based control is presented here which work well under weak grid conditions. Due to the presence of more nonlinear and dynamic loads, load current is rich in harmonic content in a highly polluted grid and this harmonic content penetrate in to the source side and makes source current non sinusoidal in nature. For this purpose several control algorithms have been proposed to attain power quality improvement. But under highly polluted grid condition these controls does not work properly. MCCF ISOGI based control is a better solution for highly distorted grid condition. MCCF control algorithm is used to extract the fundamental component of weak grid voltage which is further used for the grid synchronization. This control algorithms are mainly implemented to improve the power quality of the grid in terms of harmonic elimination, load balancing and power factor correction. From the performance evaluation, the MCCF-ISOGI based control works satisfactorily under various dynamic conditions such as unbalanced load and distorted grid. The Incremental Conductance(INC) Maximum Power point Tracking(MPPT) technique is used to track the maximum power from the solar array. This is achieved through the effective extraction of crest power from an solar PV array and control the DC bus voltage. The performance evaluation of the proposed control algorithms are verified by simulation results and satisfactory results are obtained.