Consumption estimation method for battery-electric buses using general line characteristics and temperature
Péter Ákos Szilassy, Dávid Földes
Abstract
Though the battery capacity is increasing, in day-to-day operation, battery-electric buses (BEB) are still not able to replace buses with combustion engine one by one. Determining the best option to purchase or the daily operation of a BEB requires consumption estimation. Generally, the consumption is calculated using real data from test runs; however, testing an electric bus has a high cost. Without preliminary data collection, estimating the consumption is a barely studied area. The paper aims to elaborate a consumption estimation method applied in a data-deficient and inexperienced environment using general route characteristics. The consumptions of the drivetrain and auxiliary system are calculated considering uncertainties affecting fluctuations, such as ambient temperature, topography, stop spacing, and passenger load. The method developed was applied as a case study and verified by real-time consumption data. The minimum energy consumption is determined by considering the largest consumers, which correlate with the data measured in real conditions. According to the application, the calculated consumption of buses is feasible and basically provides a fairly good approximation. Estimating the driving dynamics also gives a good approximation; however, the differences are significant if the consumption of cooling and heating and other electric auxiliaries are also considered. The result of the method is a rough estimation of the energy consumption in a line which can be applied for decision making before purchasing a new BEB or introducing a BEB on a new route.