Requirements analysis of operation monitoring for electric vehicle in transportation industry

Abstract

Ensuring the operation efficiency and safety of electric vehicle is one of the main tasks of promoting the application of electric vehicle in transportation industry. Based on the operation characteristics of electric vehicle in transportation industry, the requirements of operation monitoring for electric vehicle were analyzed in this paper. Firstly, the operation processes of electric bus under typical urban conditions were simulated by the software of Advisor, and the potential faults of the battery pack during vehicle operation were demonstrated. Secondly, the peak power capability and driving range of electric bus under different conditions were studied by bench test and simulation software, and the effects of the state of charge (SOC) and temperature of battery pack on bus’s operation capability were analyzed. Lastly, the aging characteristics of battery were researched by accelerated aging test, and the impacts of the battery aging on its ohmic resistance and available capacity were analyzed. The analysis results indicate that the change amplitude and frequency of the charging/discharging current of battery are drastic under typical urban driving conditions, which can easily lead to the battery risks such as over charge, over-discharge, and thermal runaway; both of the SOC and temperature of battery have obvious effect on the peak power capability and driving range of electric bus, and these two parameters can decline by about 50% when the battery temperature decreased from 20 to 0 °C; the loss of available capacity is mainly caused by the increase of ohmic resistance when the battery is aged, and the average loss rate of available capacity can be about 30–50% after one year of vehicle operation.