Hosting Capacity Assessment Method of Electric Vehicles Connected to Distribution Networks Based on Improved Whale Optimization Algorithm

To address the issues of insufficient power supply capacity in distribution networks caused by large-scale integration of electric vehicles (EVs), this paper proposes a hosting capacity assessment method of EVs connected to distribution networks based on the improved whale optimization algorithm (IWOA). The approach considers both the accuracy of distribution networks modeling and the complexity of optimization process, aiming to enhance the scientific rigor and accuracy of charging station planning. First, considering multiple constraints such as power flow balance, node voltage, branch current and transformer capacity, a nonlinear optimization model with the objective function of maximizing the total charging power of the node is constructed. Second, by using the exterior penalty function method combined with the power flow simulation model, the nonlinear constraint problem is transformed into a solvable unconstrained problem. Third, on the basis of the traditional whale optimization algorithm (WOA), nonlinear cosine convergence factors and dynamic adaptive weight coefficient are introduced to enhance the search ability and stability of the algorithm. Finally, simulation analysis is conducted on an actual 21-node distribution networks. The results show that the proposed method can effectively assess the hosting capacity of EVs connected to distribution networks; the solution accuracy and convergence stability is superior to WOA. It provides strong decision support for EV charging facility planning.