Vehicle Control Development - Converting a Medium-Duty Commercial Truck into a Battery Electric Vehicle 2024-01-2047

The transition towards electrification in commercial vehicles has received more attention in recent years. This paper details the conversion of a production Medium-Duty class-5 commercial truck, originally equipped with a gasoline engine and 10-speed automatic transmission, into a battery electric vehicle (BEV). The conversion process involved the removal of the internal combustion engine, transmission, and differential unit, followed by the integration of an ePropulsion system, including a newly developed dual-motor beam axle that propels the rear wheels. Other systems added include an 800V/99 kWh battery pack, advanced silicon carbide (SiC) inverters, an upgraded thermal management system, and a DC fast charging system.

A key part of the work was the development of the propulsion system controls, which prioritized drivability, NVH suppression, and energy optimization. The improvement of the electrified truck compared to the gasoline version in responsiveness and reduced noise emissions underscores the efficacy of the BEV's design. This enhanced performance was substantiated by a quantifiable reduction in brake use, resulting in improved energy efficiency.

This paper describes the development, implementation, and verification of the vehicle control systems, including the interface with the existing production vehicle controllers, the inverter control strategy, a one-pedal driving function, the management of the DC fast charging protocols, a thermal management system, fault diagnosis algorithms, and an intuitive in-vehicle display interface. Performance evaluations have demonstrated a remarkable 40%+ improvement in the BEV's 0-100 km/h acceleration compared to the gasoline-powered stock vehicle. The paper also addresses some obstacles encountered during the electrification process.