Combination Decision Model in Long Time Scale considering Coordinated Charging and DT Extension

With the access of cluster electric vehicles, the distribution capacity will become more and more insufficient. In this paper, the typical basic load curve of public distribution transformer (DT) was obtained by cluster analysis, and a complete model of EV charging load was established. In consideration of the development trend of basic load and EV charging load, a natural growth model of DT was built. Further, the combination decision optimization model in long time scale was proposed, aiming at minimizing life cycle cost of coordinated charging and DT extension. Taking a real residential area as an example, firstly, a natural load growth model of the DT in the area was built. Secondly, by solving the combination decision model, the best time to start coordinated charging could be determined, as well as the best extension time, capacity and type of the new DT. Finally, by analyzing the influence of the user acceptance of subsidies, the extension year and type of the transformer, it was proved that the model proposed is economical and practical.