Techno-Economic and Environmental Performance of Electric Drive Trailers in Heavy-Duty Commercial Vehicles: A Coordinated Torque Control Approach

Although critical to modern logistics, heavy-duty commercial vehicles face mounting pressure to improve energy efficiency and reduce emissions. The aim of this study was to evaluate the techno-economic and environmental performance of four vehicle configurations: internal combustion engine (ICE) tractors and battery electric tractors (BETs), each respectively paired with either a conventional or an electrified trailer. To optimize energy utilization while proactively mitigating the longitudinal impact risks that trigger vehicle instability, a coordinated control strategy based on power decoupling and a real-time, efficiency-oriented torque distribution strategy were designed. Simulations under C-WTVC and CHTC-TT cycles revealed that electrified trailers substantially improved the system efficiency. Under fully loaded conditions, BETs paired with electrified trailers reduced the direct energy expenditures by 76.5% compared to conventional ICE vehicles. Notably, compared to pure electric tractors with conventional trailers, the addition of electrified trailers further reduced the energy consumption by 29.1%. Meanwhile, ICE tractors paired with electrified trailers achieved a 35.6% energy cost reduction. Furthermore, a fuel-cycle well-to-wheels (WTW) assessment of the use phase, based on a specified regional grid emission factor, demonstrated that the BETs and hybrid configurations reduced the operational greenhouse gas emissions by 64.9% and 29.3%, respectively, compared to the baseline. These findings indicate that trailer electrification offers consistent economic and environmental benefits under the simulated scenarios, thereby providing a robust theoretical foundation for the low-carbon transition, transportation sustainability, and selection of sustainable technologies in road freight.