Research Of Control Strategies For Electric Vehicle Charging And Discharging Simulation Device

Based on the analysis of interaction between electric vehicles and grid, this paper will analyze the circuit topology and working principle of the AC/DC module and DC/DC power conversion module, and provide the system operation control strategy and the main circuit parameter selection methods. The5sets of power batteries in the laboratory are processed the mathematical mode which is based on the OCV-SOC characteristics. The simulation model of the Charge and discharge system is built in PSCAD environment, the traditional two-stage of constant current-constant voltage charging and pulse charging mode are achieved. Comparing with the measured curve, the correctness of the battery model that based on the OCV-SOC characteristics is verified. According to the simulation analysis, the feed-forward control of the power balance can improve the anti-jamming capability of the system for the load mutation and voltage fluctuations. The balance of DC bus power is analyzed by the multiprocessor of the charging and discharging simulation. When electric vehicles used as decentralized energy storage, according to the superior power of instruction, it achieved flexibility to quickly output power to stabilize the grid load shifting and the intermittent new energy function.Aiming at improving the deficiencies of charging equipments, the EV charging and discharging system is pointed which is based on the point of the Direct Current(DC) power bus. This system can effectively reduce distribution capacity and improve equipment utilization, the integration of "charge, discharge, storage" function is convenient for the orderly management of EV charging and discharging. Based on the functional requirements, of the EV charging and discharging system has been detailed designed, including the system overview, the electrical topology, the functional analysis of monitoring systems, communications circuits and the software control system, and the working principle and platform build system solution are also provided.The EV charging and discharging systems is tested and analyzed, including the standby and start, the DC bus voltage steady, following and anti-load disturbance characteristics and charging performance experiments. And from the two aspects, equipment performance and the harmonic current and power factor, EV charge and discharge system is compared with the existing changer to analyze each characteristics besides the advantages and disadvantages.