Performance test and analysis of key components of pure electric vehicles

Abstract

Tests are performed in this article to analyse the lithium iron phosphate (LiFePO4) battery performance and drive motor system performance, so as to give a sufficient understanding of performance characteristics of key components of pure electric vehicles (EV). The EV powertrain system performance test bed is applied for the tests. Applying a LiFePO4 battery (192 V/100 A·h) as the research object, a calculation method is developed for battery charging/discharging efficiency. Tests are performed to analyse the influence of battery temperature on terminal voltage, as well as the influence of battery SOC and charging/discharging current on the battery efficiency. Applying an AC asynchronous motor (rated power 32 kW) as the research object, tests are performed to analyse the influence of battery voltage on the performance of motor system, the efficiency characteristics of drive motor within the high-speed field weakening area, and the efficiency characteristics of drive motor in normal working conditions. Through the tests and analysis for the performance of EV battery and motor, it can provide guidance for the matching of EV powertrain system, and gives basis for development of high-efficient EV control strategies.