Power and voltage stability analysis of electric vehicle distribution network considering virtual power plants

Electric vehicles (EVs) are receiving increasing attention because of the development of renewable energy. Operators are promoting the use of EVs as virtual power plants (VPP) to improve the reliability of existing power grids. However, the integration of EVs will have a significant impact on the stability of the distribution network. In view of this, a dispatching cost model for EVs is proposed based on active power and reactive power, which is aggregated into a comprehensive cost model for VPP. In addition, corresponding hierarchical control strategies and dispatching optimization models for VPP are proposed to minimize the total generation cost of generators and VPP in the distribution network based on a robust optimization approach. The simulation tests the proposed hierarchical control strategy and dispatching optimization model on an IEEE9 node system as a test distribution network. The results show that the EV cluster as a VPP effectively reduces the output of other generators and the loss of active power for the whole distribution network, improving the power and voltage stability of distribution network nodes.