Techno-Economic Analysis and Optimal Sizing of Stand-alone Hybrid AC-DC Microgrid by Nature inspired Firefly algorithm and Particle Swarm Optimization

Abstract

Techno-Economic analysis of microgrid and its optimal sizing is a complex multi-objective problem. This complexity is due to the uncertainty of resources and connected load. The objective in standalone mode is overall cost minimization while fulfilling all the connected load demand. In this study, microgrid components are system are Photovoltaic system, dispatchable Diesel Generator, Wind Energy Conversion system and Battery Energy Storage System. Along with Optimal sizing, techno-economic analysis is carried out for two different scenarios and results are compared using nature inspired Firefly Algorithm (FA) and Particle Swarm optimization (PSO). For optimal sizing of microgrid with energy storage, State of charge of battery (SOC) is decision making factor and for techno-economic analysis diesel generator fuel cost is most important factor. Scenario 1 is considering subsidized fuel cost, and SOC of battery and scenario 2 is considering unsubsidized fuel cost and without considering the State of charge. The results show that only under subsidized cost of fuel, the operation cost is minimum of the but pollution level is very high. If the subsidy is eliminated then, only power from renewable energy sources is more attractive option. The Energy level in battery is very important factor which impacts overall cost of the system. Reliability indices of microgrid in Stand-alone mode “Loss of load probability indices” are also calculated to examine the optimal sizing of the system. Comparing the results of both Nature inspired algorithms, it is found that Firefly algorithm converges earlier and gives better minimized cost as compared to PSO.