Design and Analysis of Parallel Hybrid Electric Vehicles for Heavy-Duty Truck Applications in a Total Cost of Ownership Framework 2018-01-5025

Due to the potential on decreasing fuel consumption and design flexibility, parallel configurations are widely used for hybrid electric vehicles (HEVs). However, the fuel economy and economic profitability of parallel HEVs for heavy-duty truck applications under Chinese driving conditions still need to be investigated. It is uneasy to improve the fuel economy of parallel HEVs with a single electric motor from control perspective only. In this article, the battery size of the architecture is optimized by using the dynamic programming (DP) approach, based on a dynamic degradation model of the LiFePO₄ battery. Moreover, based on the DP results, a near-optimal control strategy of the hybrid powertrain system for online application is proposed. Finally, with two economic assumptions, the initial costs, operation costs, and payback periods are obtained in a total cost of ownership framework perspective. The simulation results show that the fuel consumption can satisfy the Stage 3 fuel consumption standard, which will be implemented in 2021. In addition, more than 18% fuel economy is achieved when compared to that of the conventional heavy-duty truck. Under present economic scenarios, the payback period of parallel hybrid electric heavy-duty truck is less than five years. When assumptions are benefited to electrification, the payback period will even be less than three years.