Abstract:

The disordered charging behavior of large-scale electric vehicles will immeasurably impact the distribution grid. How to simultaneously solve the demand for charging and discharging of large-scale electric vehicles and the safe operation of the distribution grid has been a research hotspot in recent years. In response to this problem, firstly, we mathematically model the problem; secondly, according to the nonlinear characteristics of the optimization model, in order to find the optimal solution accurately and quickly, using the improved second-order cone method to transform it, which solves the problem well:(1) “Where” problem, that is, to find the best nodes to charge and discharge electric vehicles in the distribution grid, (2) “When” problem, that is, when is the best time to charge and discharge electric vehicles, (3) “How” problem, that is, how many electric vehicles are connected to the distribution grid at the right location and the right time. Finally, using the Matlab-based Yalmip modeling tool to call the Cplex mathematical solver to verify the IEEE-33 nodes power distribution system, the results show that the proposed method not only solves the charging and discharging requirements of large-scale electric vehicles but also ensures the stability of the power grid run.