Optimized Energy Management of Battery and Fuel Cell Hybrid Buses

Abstract

Hybrid buses have electric engines powered by more than one energy source, which can reduce polluting gas emissions as long as they use clean energy. In this type of bus, the energy management system (EMS) determines the best source for each operation. However, the implementation of hybrid electric buses in the public transport fleet has high costs involved; energy management strategies that improve energy use and that can have economically viable costs to increase their penetration in the transport sector become relevant. This work presents a mathematical model to help define the parameters of the EMS algorithms used in hybrid buses with batteries and fuel cells. This model allows you to optimize the energy management of the hybrid buses, minimizing energy consumption while the equipment’s maximum current and voltage values are respected. The model is applied in the offline simulation of the energy management of a bus on the ABC metropolitan corridor that connects the San Mateus and Jabaquara terminals to connect the ABC region with the city of São Paulo. When there is only one energy source on the bus, and it is not necessary to have an EMS, it was found that the proposed model achieves a reduction in recharging cost of 11.44 % at the end of daily operation. Such savings can help enable greater penetration of hybrid buses in urban areas.