Routing and Scheduling of Electric Buses for Resilient Restoration of Distribution System

Electric buses (EBs) have been widely adopted in public transit. EBs can feed power back to the distribution system (DS) at a charging station and serve as temporary mobile power sources (MPSs), such as hurricanes. Thus, they have great potential to enhance grid resilience against meteorological disasters. This article proposes a DS restoration method for enhancing resilience considering the routing and scheduling of a group of EBs. To maintain the function of EBs in public transit, we establish an EB scheduling problem (EBSP) with predetermined optional service trips. The schedule must meet a certain public transit demand, and the not-in-service EBs can transfer power among charging stations, unleashing their abilities as MPSs. The proposed model considers the en-route energy consumption of EBs, and the restoration process aims to minimize the losses of loads over time and the energy usage of EBs for supporting the grid. The problem is finally cast as a mixed-integer linear program (MILP), which can be processed by off-the-shelf solvers. The proposed model is tested on two systems with dozens of EBs. The results validate our work’s effectiveness and demonstrate the potential of EBs in enhancing the resilience of DSs.

I. Introduction

In recent years, natural disasters frequently strike coastal cities and cause severe damages to the distribution systems (DSs), which possess limited dispatchable resources [1]. Deploying backup units and energy storage equipment can enhance resilience and quickly pick up loads in extreme weather conditions, such as hurricanes [2], but the extra investment is also high compared to their utilization rate. Electric buses (EBs) are now widely used in public transit [3]. The international energy agency predicts that the number of EBs on the road will reach 1.5 million [4]. If used appropriately, EBs will have great potential in the DS resilience restoration.