Communicationless Flexible Interconnection Technology For Wide Access Of Charging Piles

Abstract

With the wide access of electric vehicles (EVs), the problem of low voltage at the end of LVDN will be caused. Soft open point (SOP) is a new type of flexible interconnection device (FID) that can be used for voltage regulation at the end of feeder in distribution network. However, the existing SOP voltage regulation scheme needs to know the voltage value of all the feeder terminal nodes, which requires good communication conditions between the feeders of the distribution network. In this paper, a voltage control strategy for large-scale charging piles connected to FID network is proposed. Based on VSC active-reactive power coordinated voltage regulation, the flexible interconnection system at the end of the feeder knows the voltage and power information of the PCC node through the change of the DC bus voltage. Through the coordinated control of the AC and DC line voltage of the flexible interconnection system, it can realize the voltage limit control of the multi-terminal flexible interconnection distribution system without relying on the system communication conditions, and effectively improve the system’s ability to accept EVs.