HYBRID POWER SYSTEM STABILITY AND OPTIMIZATION OF AUTONOMOUS MICROGRID USING HOMER

Electricity is the most versatile form of energy available and it can be accessed all over the globe through a series of tried and tested technologies. In today’s world, attention is being focused more and more on acid decomposition and global warming due to diminishing of fossil fuel energy sources. In India, demand of electrical power is very large as compared to generation and the power transferred from one end to other suffers greatly from power quality, voltage sag and swell problems, harmonic currents in supply lines etc. followed up by large voltage and frequency variations, power cuts and load shedding. Consequently, use of renewable energy sources (RES) is more attracting to extract most of energy out of them as they are pollution free, cost free, eco-friendly and available freely in nature. They are gaining importance due to skyrocketing prices of fossil fuels and energy crisis. Each renewable energy (RE) have different present and future expected costs, present industrial base, availability, security of energy supply etc. and is in a stage of research, development and commercialization. As the use of RES is being increasing now-a-days, hybrid power systems produce synergistic benefits. To prove this fact, technical analysis is carried out on two individual standalone systems comprising of wind and mini hydro plants connected to single machine infinite bus (SMIB) and then these two systems are connected in hybrid mode along with grid integration. The analysis is done using Sim Power Systems Toolbox of Simulink/MATLAB. Various unsymmetrical faults are implemented on standalone and hybrid systems and transient stability analysis is analyzed in detail. The results show that the critical fault clearing times and reliability of power supply increases greatly when hybrid systems are used and further by using storage devices. The economic analysis is also carried out on standalone and hybrid systems with/without grid integration and battery storage device for three different cases viz. wind-diesel, hydro-diesel and wind-hydro-diesel. The analysis is carried out using Hybrid Optimization Microgrid for Electric Renewables (HOMER) optimization software. The sensitivity analysis is also carried out for different sizes of diesel generator. The optimization analysis is carried out providing the most optimum and feasible solution amongst hybrid systems mentioned above. The comparison of total life cycle costs of various standalone and hybrid systems is also presented.