Simulation of electric buses on a full transit network: Operational feasibility and grid impact analysis

This paper presents a twofold modelling exercise to investigate the implementation of battery electric buses (BEBs) in a full transit network. First, using three BEB concepts: flash, opportunity, and overnight, a real-time simulation model is developed for a full transit BEBs operation in order to (1) quantify the energy demands, (2) design the required infrastructure of the charging station, (3) test the transit operation feasibility, and (4) generate the charging load profile. Simulation results show that flash and opportunity BEBs are more feasible for full transit BEBs operation, however they suffer from high and intermittent power demands. Second, the generated charging load profile for each BEB operation is utilized to study its impact on the utilization and lifetime of the transformers, and the operation of the local distribution grid. Results indicate that the operation of overnight electric buses is more feasible as it relates to their impacts on the substation transformer and distribution feeders overloading, voltage regulation and quality aspects, and operation of voltage control devices. Collectively, findings from this study highlight that the selection of BEBs in a full network transit operation hinges on achieving feasible operation while reducing impacts on utility grid. Insights derived from this work can help optimize the implementation of BEBs in transit context.