Energy Management System of Electric Bus Equipped with Regenerative Braking and Range Extender

Electric buses are usually designed with various energy management features to overcome the limited cruising range problem. This paper reveals the impact of different energy management systems applied in the electric bus intended for rapid transit usage on battery state of charge and energy consumption. Different systems can be distinguished based on combinations of range extender usages and regenerative braking strategies. Simulations have been done using models developed from the fundamental theory of vehicle engineering and the bus's design parameters. The results show that the minimum energy consumption can be achieved by an energy management system, adopting a serial regenerative braking strategy without the use of a range extender. It is also found that the serial regenerative braking strategy can save up to 15 % energy compared to the absence of the regenerative braking system. In comparison, the absence of a range extender contributes to a 7 % reduction in energy consumption. However, considering the range anxiety of the driver, the designed electric bus for rapid transit is recommended to utilize both the range extender and parallel regenerative braking strategy. The developed model in this work can be implemented to redesign or further optimize specific components and operating procedures of the bus.