DM-i超级混动构架限扭器匹配关键技术研究

比亚迪DM-i超级混动构架是行业创新产品,其发动机输出端限扭器匹配开发比传统动力难度大、问题多。基于仿真建模进行机理分析,同时结合某DM-i车型在启动瞬态和怠速稳态等工况出现的动力系统冲击和扭振引起的整车抖动、齿轮敲击问题,研究限扭器的物理参数匹配,以及系统控制策略对其的影响,并提出了优化方向。

DM-i超级混动整车抖动机理分析及优化

比亚迪DM-i超级混动构架是行业创新产品,其搭载的某车型在大油门起步和倒挡上陡坡时,整车有明显抖动现象,易产生用户抱怨。基于Amesim软件对其进行整车一维建模,分析问题机理,并给出整车策略的优化方案。最后在实车上验证调试,效果显著,解决了问题。

Study on ultracapacitor-battery hybrid power system for PHEV applications

For the battery only power system is hard to meet the energy and power requirements reasonably, a hybrid power system with uhracapacitor and battery is studied. A Topology structure is analyzed that the uhracapacitor system is connected with battery pack parallel after a bidirectional DC/DC converter. The ultracapacitor, battery and the hybrid power system are modeled. For the plug-in hybrid electric vehicle （PHEV） application, the control target and control strategy of the hybrid power system are put forward. From the simulation results based on the Chinese urban driving cycle, the hybrid power system could meet the peak power requirements reasonably while the battery pack＇ s current is controlled in a reasonable limit which will be helpful to optimize the battery pack＇ s working conditions to get long cycling life and high efficiency.

Hybrid Supply for-Automotive Application Using Supercapacitors

In this article, the replacement of the car battery by a hybrid supply is proposed. The specific power of the supercapacitor makes it very attractive for the startup of the car. This component has very high lifetime （1 million of cycles） which can improve the lifetime of the supply （for starter or starter-alternator）. After the identification of the internal combustion engine torque developed at the startup, the validation of the hybrid supply interest is proved by the simulation of the system using Matlab-Simulink software. Finally, a test bench is developed in the laboratory to validate the simulation results.

Supercapacitors and Battery Energy Management Based on New European Driving Cycle

This paper presents a new strategy of embedded energy management between battery and supercapacitors （SC） for hybrid electric vehicles （HEV） applications. This proposal is due to the present trend in the field, knowing that the major drawback of the HEV is the autonomy problem. Thus, using supercapacitors and battery with a good energy management improves the HEV performances. The main contribution of this paper is focused on DC-bus voltage and currents control strategies based on polynomial controller. These strategies are implemented in PICI8F4431 microcontroller for DC/DC converters control. Due to reasons of cost and available components （no optimized）, such as the battery and power semiconductors （IGBT）, the experimental tests are carried out in reduced scale （2.7 kW）. Through some simulations and experimental results obtained in reduced scale, the authors present an improved energy management strategy for HEV.

Recouping Braking Energy from Diesel-Hauled Commuter Trains

Research was undertaken to define the concept of a coach-based braking energy recoupment, storage and regeneration system to augment the acceleration of regional commuter trains hauled by diesel locomotives. Functional specifications were developed having the goal of increasing by 25% the acceleration rate of a train consisting of 10 bi-level coaches hauled by a 3,000 hp diesel locomotive, typical of the rolling stock now in commuter services in Canada and the USA. Examining three alternate hybrid system technologies for train retardation based, respectively, on hydrostatic, battery and ultracapacitor energy storage. The ultracapacitor hybrid system appeared the most promising due to the capability ofultracapacitors to repeatedly and rapidly accept large energy charges without degradation, temperature insensitive and flexible in the placement of modules in the limited space available. Analyses of train operation simulations showed that in addition to augmenting acceleration and reducing trip time, braking energy recoupment reduced fuel consumption and concomitant diesel emissions.

Graphene-based Li-ion hybrid supercapacitors with ultrahigh performance

There is a growing demand for hybrid supercapacitor systems to overcome the energy density limitation of existing-generation electric double layer capacitors （EDLCs）, leading to next generation-Ⅱ supercapacitors with minimum sacrifice in power density and cycle life. Here, an advanced graphene-based hybrid system, consisting of a graphene-inserted Li4Ti5O12 （LTO） composite anode （G-LTO） and a three-dimensional porous graphene-sucrose cathode, has been fabricated for the purpose of combining both the benefits of Li-ion batteries （energy source） and supercapacitors （power source）. Graphene-based materials play a vital role in both electrodes in respect of the high performance of the hybrid supercapacitor. For example, compared with the theoretical capacity of 175 mA-h.g-1 for pure LTO, the G-LTO nanocomposite delivered excellent reversible capacities of 207, 190, and 176 mA·1h·g-1 at rates of 0.3, 0.5, and 1 C, respectively, in the potential range 1.0-2.5 V vs. Li/Li＋; these are among the highest values for LTO-based nano- composites at the same rates and potential range. Based on this, an optimized hybrid supercapacitor was fabricated following the standard industry procedure; this displayed an ultrahigh energy density of 95 Wh·kg-1 at a rate of 0.4 C （2.5 h） over a wide voltage range （0-3 V）, and still retained an energy density of 32 Wh·kg-1 at a high rate of up to 100 C, equivalent to a full discharge in 36 s, which is exceptionally fast for hybrid supercapacitors. The excellent performance of this Li-ion hybrid supercapacitor indicates that graphene-based materials may indeed play a significant role in next-generation supercapacitors with excellent electrochemical performance.

Comparison of the topologies for a hybrid energy-storage system of electric vehicles via a novel optimization method

The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric vehicles.Three aspects of such combination efforts were considered for evaluating the four types of hybrid energy-storage system(HESS)topologies.First,a novel optimization framework was proposed and implemented to optimize the voltage level of a battery pack and an ultracapacitor pack for the four types of HESS topologies.During the optimization process,the dynamic programming(DP)algorithm was iteratively applied to determine the optimal control actions.The simulation results with DP were used to evaluate the energy efficiency of different HESS topologies at different voltage levels.Second,the optimized voltage level of the battery and ultracapacitor in each topology indicates that a higher voltage level usually results in a better system performance.The simulation results also illustrate that the optimized rated voltage level of the battery pack is approximately 499.5 V,while for the ultracapacitor pack,the optimized voltage level is at its maximum allowed value.Note that the constraint of the battery voltage is initialized at200–600 V.Third,the control rules for different HESS topologies were obtained through the systematic analysis of the simulation results.In addition,advantages and disadvantages of the four topologies were summarized through evaluation of the efficiency and operating currents of the batteries and the ultracapacitor.