Modelling of energy consumption of electric buses, sizing of the battery for selected routes, and impact of their recharge on the grid

Details

Supervisors

De Jaeger, Emmanuel

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil électromécanicien, à finalité spécialisée: énergie

Abstract

This work is focused on the energy consumption of Battery Electric Buses in different conditions. The number of Battery Electric Buses (BEB’s) is growing quickly. For example, 1714 BEB’s were registered in Europe in 2020, which is 18.4% more than the previous year [1]. This is driven by more stringent local and national environmental regulations, improvement in battery density and cost, and by positive return of experience from already deployed buses. Manufacturers and transit agencies usually only announce information on the average Energy Demand of BEB’s. This information is not representative of the various conditions that can experience a BEB during its exploitation. This graduation work was made in collaboration with Engie Laborelec, a leading expertise and research centre in electrical power technology. This master thesis begins with a review of the literature on the Battery Electric Buses with more than 100 articles reviewed. The available consumption results obtained in real-world conditions and using simulation tools were extracted and sorted using parameters that describe best the different driving conditions experienced by a BEB during its operation. The parameters that had the biggest impact on the energy consumption were the traffic conditions (average speed, acceleration/deceleration, ...) and the HVAC system. The results found in the documents used in the literature review were collected and used to train different machine learning models to estimate the energy demand of the BEB’s. These models were tested on 3 existing bus line that represent urban, extra-urban and mixed driving conditions. The consumption results obtained are consistent with the values found in the literature with an increase in consumption depending on the exterior temperature and during the peak hours. The battery size required for a 12m BEB was then computed and the benefits of fast-charging on the battery size was studied. Finally, the impact on the grid was analysed using 2 different charging methods. 1: Fuel types of new buses, https://www.acea.be/press-releases/article/fuel-types-of-new-buses- electric-6.1- hybrids-9.5-diesel-72.9-market-share-i, accessed 23-April-2020