Research On Control Strategy Of Microgrid With Electric Vehicle Charging And Discharging Device

With the rapid development of the global economy, how to solve the increasingly serious energy crisis and environmental pollution has become the most important issue in today’s society. Electric vehicle uses battery as energy source, with energy-saving, pollution-free and zero emissions characteristics, it can not only be used as the power load, but also be used as distributed generation unit to provide electricity for the power grid, as integrated with renewable energy, it can effectively stabilize the wind sloar disturbance and solve the energy storage problem, From the entire process of energy generation to consumption, it achieves a clean, efficient energy utilize and creates zero emissions in the true sense.This paper proposed to integrate electric vehicle charging and discharging device with wind energy and solar energy by microgrid Firstly, discussing the current development in the home and abroad of electric vehicle charging and discharging and microgrid technology and their simulation model, control strategy. Building simulation model with AC/DC and DC/DC two-tiered structure, and combined with battery charging and discharging characteristics and micro-source classical control theory, proposed a charging control strategy, which begins with constant current ends with constant voltage and PQ or V/f discharge control strategy based on microgrid demand. Secondly, establishing the wind and solar simulation model, then building a typical microgrid composed of inverters-based on multi-micro-generators and adopts the master/slaver control strategy, that is, centralized charging and discharging device acts the master control source, while wind, solar and distributed charging and discharging device act as slaver control source. Finally, using PSCAD software to separately simulate the single charging and discharging device and microgrid under grid-connected mode, islanded mode and their transition mode. The bidirectional energy flow of charging and discharging device has been achieved, while microgrid have achieved smooth operation under transition mode, provided voltage frequency support under islanded mode and ensured grid security, stability. The results demonstrate the feasibility and capability of the control strategy, and established the solid foundation for the microgrid experimental platform application.