Wang Qianggang

Hierarchical coordination control of multi-microgrids system in series and parallel structure

Multi-microgrid system has high power distribution reliability, improve distributed power generations installation. This paper researches the sub-microgrid system in series and parallel system structure and design two hierarchical control schemes of multi-microgrid system in series and parallel structure. Then the functions of power management, state management and synchronous control in MicroGrid Central Controller (MGCC) are analyzed. For tie-line power control, grid-connected and islanded mode switch of multi-micro-grid system, this paper researches MGCC coordination strategy among sub-micro-grid systems of multi-microgrid system in series and parallel structure, researches method of multi-microgrid system synchronized control. According to the experimental system, a multi-microgrid system model in series and parallel structure is build in Matlab / Simulink software. Then simulation and analysis are conducted for tie-line power control and dynamic characteristics of synchronization process, in order to verify the correction and effectiveness of the control strategy.

Study on the proportional allocation of electric vehicles with conventional and fast charge methods when in distribution network

This paper studies the hierarchical classification of electric vehicles (EV) by analyzing the differences of charging behaviors of different types of EVs. According to the different proportions of conventionally-charged EVs and fast-charged EVs, four indexes (the increment of peak load, the duration of peak load, the maximum smoothing index of load curve and the average smoothing index) are proposed to evaluate the impact on the distribution network. Then a method is established to configure the proportion of EV in different charging methods. Finally, based on the field data of a distribution network and the IEEE-34 node example, the optimal proportion of EV in different charging methods are made combined with the Monte Carlo simulation of charging load. Results show that suitable ratio of EV with different charging methods can make the load curve smoother and the grids difference between peak and valley loads decrease significantly.