Voltage Security Considerations in Optimal Operation of BEVs/PHEVs Integrated Microgrids

Nowadays, it is a common concern for modern electrical networks and energy management systems to derive an optimal operation management considering energy costs, pollutant emissions, and security, of the system in the presence of plug-in electric vehicles (PEVs). In this paper, a multiobjective optimization problem is solved to schedule power sources in a typical microgrid, while PEVs are viewed as a stochastic factor. PEVs residing in a city are considered as probable loads and/or generations depending on how they interact with the utility grid. A novel stochastic methodology is used to calculate the 24 h expected power demand and generation of vehicles aggregated in municipal parking lots. The objective functions of the problem are voltage security margin to be maximized and the total power losses, the total electrical energy costs, and the total emissions of power sources, which should be minimized. Based on different scenarios, the impact of PEVs penetration on base load, voltage profile, and also the value of objective functions, are assessed. Numerical results show the effect of different fleets of PEVs, as well as on the operation of future microgrids.