OPTIMAL SIZING OF SOLAR-WIND HYBRID GRID CONNECTED MICROGRID WITH BATTERY STORAGE

Abstract

Non-conventional sources such as photovoltaics & wind is the major source of energy in a microgrid. But their erratic nature due to their dependency on climatic conditions causes uncertainties. Energy storage can absorb surplus power and release it when there is deficiency of power. Therefore, energy storage will facilitate in the incorporation of renewable energy with the grid. The optimal sizing of batteries and other components of microgrid is important as it prevents oversizing or under sizing of batteries and different components. In this research project, solar panel and wind turbines are modelled mathematically, and their output power with respect to solar irradiance, temperature and wind speed has been simulated using MATLAB. A control strategy that controls the exchange of power with respect to the difference between load demand and generation and battery soc is also developed. This control strategy aids in the exchange of power with grid and ensures the balance in power. Whale optimization algorithm (WOA) is used to find the optimal number of batteries, solar panels, wind turbines using the total annualized cost (TAC) as objective function. Reliability assessment also has been conducted and Loss of Load Probability (LOLP), Loss of Load expectation (LOLE), Electrical Energy Not Supplied (EENS), Loss of Power Supply Probability (LPSP) has been calculated. This optimal sizing is conducted and studied for various scenarios. In this work, there are mainly 2 scenarios, with grid connection and without grid connection. Then each of these scenarios are divided into two based on the combination of renewable energy sources, such as solar with wind generation system and with solar photovoltaic system alone. Then again these are divided into 3 based on the changes in load, such as normal load, when increased by 10% and when decreased by 10%. Reliability assessments are also done to ensure the reliability of the system.