Abstract:

 The high power fast charging characteristics of fast charging electric vehicle station will have enormous impact on the stability of the power gird, therefore the battery energy storage system(BESS) is considered to be configured in the fast charing electric vehicle station. Through the peak load shifting,BESS can reduce the transformer capacity allocation for the charging station and  release the adverse impact of high power fast charging on the power grid. Considering the current situation that a large number of retired power batteries need to be recycled urgently in China and combining with second-use battery energy storage system ,the economic evaluation model of fast charging electric vehicle based on overall costs and incomes is built. The maximization of annual net income is used as the objective function of the model and the improved genetic algorithm is used to optimize the model. Combined with case, the economical efficiency of fast charging electric vehicle station without BESS, with conventional BESS and with second-use BESS are analysed. The optimal capacity allocation scheme of second-use BESS is determined considering the economy and the effect of energy storage to reduce load.

Key words: fast charging electric vehicle station, second-use batteries, energy storage system, capacity allocation, economic evaluation