Residual Power Supply Capacity Evaluation of Distribution Network Considering Dynamic Safety Margin of Second-use Electric Vehicle Energy Storage

Residual power supply capacity (RSC) is an important indicator for evaluating the distribution network, and as more and more energy storage systems are connected to the distribution network, it is necessary to study the impact of energy storage installation location and its own capacity characteristics on the power supply capacity of the distribution network. This paper considers using second-use energy storage (SUESS) instead of a brand new energy storage system. Firstly, this paper calculates the upper and lower limits of initial capacity of SUESS by calculating the number of retired batteries cycles and establishes the capacity attenuation model of energy storage power plant to determine the capacity attenuation during operation, dynamically updating the safety margin of energy storage. Secondly, the distribution network can be operated in an island after a failure, so this paper proposes a N-l security verification method for the distribution network with SUESS. Finally, this paper integrates the SUESS island operation model to establish the residual power supply capacity (SURSC) model with SUESS. Through analysis and comparison of distribution network examples, this method has advantages in feasibility and can effectively evaluate the remaining power supply capacity of distribution networks with SUESS.