MODELLING OF PHOTOVOLTAIC ARRAY Atul Sharma*, Abhishek Moyal**, Lokender Singh***, Parag Sharma**** * Department of Electrical Engineering, PIET, Jaipur ** Department of Electrical Engineering, SBCET, Jaipur *** Department of Electrical Engineering, PIET, Jaipur ****Department of Electrical Engineering, PIET, Jaipur *Email: atul.sharma@poornima.org **Email: abhishekmoyal@gmail.com ***Email: lokenderpiet522@poornima.org ****Email: parag.sharma@poornima.org Abstract— Renewable energy sources became a popular alternative electrical energy source where power generation in conventional ways is not practical. In parallel to developing technology, demand for more energy makes us seek new energy sources. The most important application field of this search is renewable energy resources. Two diode model when compared with a single diode model representation, it is envisaged that the two diode model representation of a PV array provides improved accuracy even at low solar irradiation levels. The reason behind going for this model is that the input parameters have been reduced so as to reduce the computational time . Further the two diode model is useful to find the I-V and P-V curves in standard test condition since it is fast, simple and accurate as well as it leads to showcase P-V and I-V curves in large array simulation and in partial shading condition. The photovoltaic effect refers to photons of light exciting electrrons into higher state of energy, allowing them to act as charge carriers for an electric current. Index Terms: Two diode model, partial shading simulation of power system, STC and fuel cell. • Introduction It is well know that energy is essential for our society to ensure the quality of life and to underpin all other elements of our economy. With advancement in technology sources have increased interest in renewable energy sources. Many societies across the world in which we live have developed a large appetite for electrical energy. This appetite has been stimulated by the relative ease with which electricity can be generated, distributed, and utilized, and by the great variety of its applications. It is arguable whether the consumption of electricity should be allowed to grow unchecked, but the fact is that there is an ever-increasing demand for this energy form. Clearly, if this demand is to be met, then the world’s electricity generating capacity will have to continue to grow. Presently almost all the electricity generation takes place at central power station which utilizes coal, oil, gas, water or fissile nuclear material as the primary fuel source. The most important factor that affects the accurateness of a simulation in the PV cell modelling, which basically involves the estimation of the non-linear current-voltage and P-V characteristics curves. The simplest model is the single diode model i.e. a current source in parallel to a diode and a resistance Rs. It require only three parameters which are the short circuit current (Isc), the opens circuit voltage (Voc) and the diode ideality factor a. This model is enhanced by the adding of one series resistance, Rp. Despite its simplicity, it showed various discrepancies at different temperature. Thus it was further improved when a resistance in parallel was connected to it. Here the Rp model was although an improved effort; but when subjected to irradiation variation it was not showing proper results. The single diode models were based on the assumption that the recombination loss in the depletion region is absent. In a real solar cell, the recombination represents a substantial loss, especially at low voltages. This cannot be adequately modelled using a single diode. Hence consideration of this loss leads to a more precise model known as the two-diode model which is the motive of the work done here. Today around 30,000 wind turbines and more than 1, 00,000 off-grid solar PV systems are installed all over the world. Wind and solar hybrid model with proper storage system have been keen interest for the last few years. Fuel Cells (FC) in combination with electrolyser (for hydrogen generation) and hydrogen storage tanks are being considered for energy storage. In this paper a hybrid model of solar /wind & fuel cell is developed and compared with the earlier model of solar/wind/battery system. The simulation circuit will include all realistic components of the system.