Abstract Power-split configuration is highlighted as the most popular concept for full hybrid electric vehicles (HEV). However, the energy management and design of power-split heavy duty truck under Chinese driving conditions still need to be investigated. In this paper , the parametric design, a rule-based control strategy and an equivalent consumption minimization strategy (ECMS) for the power-split heavy duty truck are presented. Besides, the influence of a penalty factor also discussed under ECMS algorithm. Meanwhile, two different methods to search the engine operation point have been proposed and the reason of different economy performance is presented by using energy flow chart. And the simulation results show both fuel consumption can satisfy the second phase fuel consumption standard and the third phase fuel consumption standard which will be implemented in 2020, under C-WTVC (Chinese-World Transient Vehicle Cycle). Design optimization for generator and traction motor are researched by analyzing power split device’s speed and torque characteristic. Introduction In recent years, environment concerns and security of energy supply have forced Chinese governments to explore environment friendly, efficient and sustainable transportation solutions [ 1]. And Chinese governments has promoted BEV , HEV and PHEV commercial vehicles, in response to the energy and environment crises, by carrying out strict regulations and providing subsidies. Since 2009, more than 3 million the commercial vehicles are sold per year as shown in Figure 1. Especially China will implement the third phase fuel consumption standard in 2020. The fuel consumption regulation will become more stringent. Therefore, a hybrid electrical system for a heavy duty truck under Chinese driving cycle need to be investigated, satisfying national fuel consumption standard and achieving environment friendly.In general, the main components of HEVs include an energy source (fuel), energy convertors (engine, generator, and motors) and an energy accumulator (battery or ultra-capacitor). Torque couplers or/ and speed couplers may be employed as a link between these components [ 2]. And hybrid vehicles can be classified into series configuration, parallel configuration, and power split configuration. Power split systems can again be classified into three types: (1) input split, (2) output split, (3)compound split [ 3]. The power split configurations provide both series and parallel functionality. The power split systems can enable the engine to operate around its efficient regions, and it also provide an electronically controlled continuously variable transmission (E-CVT). For these advantages, many companies and research laboratories have developed many different type power devices. The most well-known power split vehicle is Prius produced by Toyota. Figure 1. The sales and growth ratio of commercial vehicles between 2008-2016 in China Many papers have been published regarding the advantages of power split configurations, such as fuel economy improvements and emissions reductions. Some of the researches focus on energy management and design optimization of HEV . In [4], the model predictive control strategy is proposed. The energy management problem is treated as a nonlinear problem and a model is used to project the torque demand and the resulting velocity over a future Energy Management and Design Optimization for a Power- Split, Heavy-Duty Truck2017-01-2450 Published 10/08/2017 Chao Xu, Fuyuan Yang, and Jinyu Zhang Tsinghua University CITATION: Xu, C., Yang, F., and Zhang, J., "Energy Management and Design Optimization for a Power-Split, Heavy-Duty Truck," SAE Technical Paper 2017-01-2450, 2017, doi:10.4271/2017-01-2450. Copyright © 2017 SAE InternationalDownloaded from SAE International by Big Ten Academic Alliance, Tuesday, July 31, 2018prediction. Varun et.al compares the rule-based control strategy with fuzzy logic control strategy,