Multi-objective optimization of hybrid energy storage and assessment indices in microgrid

Hybrid energy storage technology has multiple effects on the microgrid, which include keeping power balanced, smoothing fluctuating power of renewable energy and improving power quality, etc.Based on a typical microgrid with photovoltaic/wind/storage and normal loads, a rational capacity allocation method for the hybrid energy storage system is put forward.A hybrid energy storage configuration multi-objective optimization mathematical model is developed at minimum cost, optimal match between power generation and load demand and best smoothing effects of renewable generation. An adaptive weight particle swarm optimization algorithm is put forward to get the optimal solution. To determine the weights of each objective function in the multi-objective optimization model, a ranking method based on average fitness deviation of each objective function is presented.To evaluate the impact of energy storage application on microgrid, assessment indices of energy storage multi-objective optimization are provided; based on which, single battery and composite energy storagemulti-objective compensation effects are compared with each other. Based on the actual data of photovoltaic/wind/load in microgrid programed by MATLAB, an illustrative example is calculated with the algorithm proposed. © 2014 State Grid Electric Power Research Institute Press