The influence of the EV charging station´s large-scale access to the backbone network

In order to study the load characteristics of the electric vehicle charging station and analyze the influence of the charging station´s large-scale access to the regional power grid, the following measures have been taken: first, analysis of the modeling with power functions that is commonly used in the electric power system load modeling; second, analysis of the energy storage and charging systems´ working principles and working modes; third, conversion of the two systems into a constant capacitive impedance load equivalent and a constant power load equivalent respectively and develop a power function model for each of them accordingly; fourth, use of the linear polynomial to express the charging station´s mixed load model of bus voltage and frequency; fifth, test of the rationality of the mixed load model by comparing the daily load curves produced by the mixed load model and the MATLAB simulation model; finally, use of PSCAD simulation method to build a backbone network and connect the Shenzhen charging stations equivalent load to the backbone model bus. The result is that the large-scale access of charging stations equivalent load can cause a sudden drop in the bus voltage and frequency. Therefore, the developed mixed load model is of great significance to the study of load characteristics of charging stations and the impact of their great access to the backbone network on the network security and stability.