Hybrid Solar Photovoltaic/Wind Turbine Energy Generation System with Voltage Based Maximum Power Point Tracking

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olar photovoltaic (PV) and wind generation (WG) systems have become two of the most promising sources of renewable energy due to the fact that their energy sources are free, abundantly available in nature and sustainable. Besides this, these energy sources are preferred for being environment-friendly. They are now well developed, cost effective and are being widely used. PV and WG applications systems have become more widespread in both developed and developing countries due to the fact that such systems are scaleable from very small to very large and easy to integrate with existing power converters. This project proposes a hybrid energy system combining PV and WG as an alternative source of electrical energy, in particular where conventional utility is not feasible to maximizing the output energy and reducing the output power fluctuations. A simple, cost effective and sensorless maximum power point tracking (MPPT) scheme is employed to achieve MPPT for both PV and WG hybrid system and to deliver this maximum power to a fixed DC voltage bus. The fixed voltage bus supplies the DC load, while the AC loads are fed through a PWM inverter. The DC voltage bus is regulated using a PWM voltage source inverter. The proposed MPPT controller has the advantages of simplicity, cost effectiveness and efficiency to extract the maximum available power of each individual source under varying climatic conditions, without measuring the irradiance of PV or the wind speed of WG systems. A new insolation and wind-speed estimation schemes are proposed based on estimating these parameters without any direct or indirect measurements using the support vector machine (SVM). Simulation of the proposed hybrid system is carried out using PSIM software and MATLAB-Simulink. In the second part the project presents the development of an efficient small-scale centralized DCbus grid connected hybrid wind/photovoltaic/fuel cell for supplying power to a low voltage distribution system. The hybrid system consists of wind and photovoltaic as a primary power system. A fuel cell is added as a secondary system to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic. The objective of this study is to design and control a hybrid system that guarantees the energy continuity. A simple control method is applied to the proposed configuration to simultaneously achieve three desired goals: to extract maximum power from each hybrid power system component; to guarantee dc bus voltage regulation at the input of the inverter; and to transfer the total produced power to the grid at unity power factor, while fulfilling all necessary interconnection requirements. The power fluctuation of the proposed hybrid system has been reduced as compared to that of each individual system and it has been completely suppressed using the FC system. The obtained results indicate that the DC-DC converters are very effective in tracking the maximum power of the wind and photovoltaic sources, the fuel cell controller responds efficiently to the deficit power demands. With both wind and photovoltaic systems operating at their rated capacity, the system can generate power as high as 2 kW and the fuel cell need not be utilized in such cases. A complete description of the proposed hybrid system along with its principle of operation is given.