Grid Tied Solar Photovoltaic Power Plants with Constant Power Injection Maximum Power Point Tracking Algorithm

Day to day there is an increase in installations of new Solar Photovoltaic Power plants (SPVPP’s) which directly reflects the grid. As the SPVPP’s output power is fluctuating in nature, which is directly injected to the utility grid faces the challenges like overloading. Therefore, to overcome the overloading situations of grid, its infrastructure should be replaced by higher ratings which will increase the system cost. Due to this there is a need to limit the grid injected power from SPVPP’s to overcome the overloading situations. In this article a Constant power injection (CPI) algorithm is used to control the feed in power to grid as per grid regulations. Based on the instantaneous SPVPP’s output power and power limiting value this strategy will controls the output power by switching between the incremental conductance maximum power point tracking (InC-MPPT) algorithm and CPI algorithm. The proposed InC-CPI algorithm is applied to the single phase two-stage (SPTS) systems with the working region is on the left side of maximum power point (MPP) for maintaining the system to be in stable conditions. In this article the InC-CPI and the perturb and observe (P&O)-CPI algorithms were compared, and results were analyzed. The proposed control algorithm is designed using Matlab/Simulink and the results taken for both clear and cloudy days with wide varying climatic conditions.