Cascade Failure Propagation in Electric Vehicle Charging Systems Considering Load Redistribution

A significant tendency in the evolution of electric vehicles (EVs) is the large-scale interconnection of power and traffic systems. When the power system failure occurs due to the extreme events, the resulting disturbances may propagate to the traffic system, which may lead to the cascading failures. This paper proposes a framework for analyzing the propagation characteristics and cascading failure of EV charging system in the coupled traffic-power system. The multilayer system theory is employed to model the power system, EV charging system, and traffic system. In order to analyze the cascading failure propagation characteristics, an AC-based Cascading Failure model (ACCF) is utilized to identify the overload branch and conduct load shedding. The EV load redistribution is modeled by the effective resistance between the nearby charging stations. In the case study, we simulate the cascade failure propagation of the IEEE 30-bus power systems coupled with EV charging system. The results show that the failure of critical power system components may cause cascade failure It is significant to guarantee the reliable service of the key charging stations during power system failure.