Exploring Control Design of a PV-Wind Hybrid OnGrid System without ESD

Abstract—there is general practice to support and compensate intermittent behavior of Solar photovoltaic (PV) system with energy storage devices (ESD) and the one generally adopted is battery energy storage (BES) simply because of lower cost as compared to fuel cells or a bank of super capacitors. However, cost of battery maintenance, inherent shorter life, even if state of charge (SOC) is regulated; involving comparatively huge capital investment is a big issue. In this paper, a stabilized hybrid photovoltaic-wind grid connected system without battery storage or ESD is developed with effective and co-ordinate control of current injection into grid with maximized harvest of PV energy using MPPT control and wind energy transfer control automatically. The control philosophy of energy transfer to PCC is an algebraic sum of energy using MPPT of PV system in relation to inverter stage while that of wind system is through wind converter. The stability mechanism of battery or ESD supported system, is getting replaced by a mechanism of current injection to grid by sharing both components of hybrid renewable sources. This is simulated in MATLAB/ Simulink to validate the effectiveness of proposed system.

Index Terms—Coordinated Current injection control, Hybrid grid, Grid connected photovoltaic, Maximum Power Point Tracking (MPPT), Renewable energy, Photovoltaic system, Wind energy.

I. INTRODUCTION e all are aware about terms like ecosystem, fossil fuel limitations, global warming, glaciers melting, co2 layer decreasing and there is increasing concern about use of Sun, Wind, water, natural gas and other natural resources on which our future will be depending to meet increasing energy demands.Further there is growing preference for distributed grids and micro-grids with majority of renewable sources like PV, wind energy storage devices (ESD) and DG sets. Being environmental resources their behavior is changing, not fully predictable and needs costly ESD.PV arrays, wind turbines, fuel cells, micro turbines, conventional diesel and natural gas reciprocating engines, gas-fired turbines, steam turbines, and energy storage technologies are some of the basic distributed resources(DR).
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