Research On The Impact Of Charge-Discharge And Storage Integrative Station On The Grid

Electric vehicle energy supply facility is one of the important factors that affect the promotion and development of electric vehicles. The charge-discharge and storage integrative station, with the integration of the charging station, discharging station and storage station, can solve a lot of problems such as scarcity of land resources in large cities, low Battery utilization, high operation and management costs and so on, thereby having many advantages.In order to study the effect which the charge-discharge and storage integrative station places on the grid, we studied the issue from several aspects such as the integration modeling, multi-variable converting devices control and simulation with MATLAB / SIMULINK, EMTP and PSCAD tools. Main work is as follows :(1) A charge-discharge and storage integrative station simulation model was built, which contained multi-variable converting device modeling, battery modeling and grid modeling. Multi-variable converting device was designed as a topology with two sets of Boost-Buck and PWM converter circuits in parallel. Based on PNGV and GNL models, a new nonlinear battery model was proposed, which can simulate battery capacity, steady and transient characteristics more accurately. Grid modeling used the three-generator and nine-bus model based on the standard of Western Systems Coordinating Council, of which the parameters were reset for the Laboratory conditions.(2) Studied the multi-variable converting device. Multi-variable converting device has four operation states: charging, half-discharging, DC-converting and full-discharging. In this thesis we focused on the control methods of the single converter operation and multiple converters in parallel operation according to four operation states of multi-variable converting device. The simulation results proved the control methods were correct.(3) Studied the effect which charge-discharge and storage integrative station places on the grid. Based on the real load data and according to the multi-objective function optimization algorithm, the charging and discharging power of the integrative station in every period was calculated. With PSCAD simulation tool, we simulated the daily load curve of the grid, thereby verifying the role of integrative station to adjust load and improve the load utilization. Meanwhile, based on the three-generator and nine-bus grid model with reset parameters, we discussed the role of charge-discharge and storage integrative station to adjust the voltage and frequency of grid. The simulation results proved the conclusion was right.