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Cai S.,Beijing Electrical Vehicle Co.
Journal of Manufacturing Science and Engineering, Transactions of the ASME | Year: 2017

In this work, a research on double-direction pressure distributions (DDPD) induced by vaporizing a single metal foil was conducted. The shock pressure in the up direction revealed the same amplitude as that in the down direction. Based on a comparison of pressure amplitudes between double-direction pressure distributions (DDPD) and single-direction pressure distributions (SDPD), the pressure upward in DDPD was found to be smaller than that in SDPD. In addition, an approach to vary the pressure amplitudes in the up and down directions in DDPD was introduced. Using polyurethane plates in different thicknesses leads to various pressure amplitudes on both sides of the foil specimen. Finally, the application of DDPD in metal forming process was examined. A profile forming part with two bulging zones was successfully manufactured. © 2017 by ASME.


Sun Q.,Tianjin University | Sun Q.,Control Applications | Wang S.,Beijing Electrical Vehicle Co. | Wei K.,Tianjin University | And 2 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2016

Based on the current control strategy with capacitor-current-feedback active damping, the average switching model for PWM converter was built under αβ stationary frame. In order to eliminate the static error of alternating current that PI controller could not achieve, the quasi PR regulator of inner current loop was employed to track the given fundamental sinusoidal current. Then the quasi DPC algorithm of out loop based on instantaneous power theory was presented. The influences of PR controller and parameters in LCL active damping loop on system's robustness were studied by the means of frequency response characteristics. Instead of Tustin discretization, Delta operator was introduced to avoid instability issues of z domain transformation and to obtain well sinusoidal current output approximating to continuous model. The simulation and experimental results verify that the proposed control strategy can achieve unity power factor with low total harmonic distortion, and the system's power quality and dynamic performance are also well improved. © 2016, High Voltage Engineering Editorial Department of CEPRI. All right reserved.


Wang Y.-H.,Beijing Electrical Vehicle Co. | Zhang C.-L.,CAS Institute of Chemistry | Yu H.-G.,Beijing Electrical Vehicle Co. | Sheng J.,Beijing Electrical Vehicle Co. | And 2 more authors.
Gongneng Cailiao/Journal of Functional Materials | Year: 2013

As was well known, the electric vehicle was a very important alternative transportation and gains more and more attentions due to the shortage of conventional fossil energy. Recently, some self-ignition accidents of the electric vehicles happened in last two years make the people recognize the importance of the safety of the battery. Therefore, the safety of the battery was the key for practical application of the electric vehicles, and therein the thermal management of battery was very important. In last decade, the thermal management system employing a novel phase change materials (PCM) has been designed and researched for lithium-ion battery. Compared to conventional thermal management systems, e.g. air/liquid-cooling, the PCM-based system has more advantages: compact, high efficient, energy conservation, little temperature variation, preventing thermal runaway etc. But the shortcomings of low heat conduction coefficient and difficultly compositing with other materials restrict the application of the PCM. Extensive efforts have been undertaken to improve the PCM performance. In this review, we introduce the recent development of the PCM-based thermal management system, and especially present the new researches in improving the thermal conductivity of the PCM by using the wax/graphite matrix. In the last, we give the conclusion and outlook, and think that the composite PCM microcapsule with high heat conduction and complex structure was the future trend.


Gao X.,Beihang University | Gao X.,Beijing Electrical Vehicle Co. | Su D.,Beihang University | Li Y.,Beijing Electrical Vehicle Co.
2015 Asia-Pacific International Symposium on Electromagnetic Compatibility, APEMC 2015 | Year: 2015

Electric Vehicle (EV) is driven by electromotor, whose power comes from vehicle power battery. The advantage of the EV is the mechanical simplicity of the drivetrain, but the electromagnetic interference (EMI) is a difficult problem to solve. This paper first describes the electromagnetic interference (EMI) phenomenon generated by one kind of DC/DC converter, Then analyses the reason of the EMI, and finally puts forward the design optimization direction of EMC from the vehicle. © 2015 IEEE.


Zhou X.X.,University of Technology, Sydney | Walker P.D.,University of Technology, Sydney | Zhang N.,University of Technology, Sydney | Zhu B.,Beijing Electrical Vehicle Co. | Ding F.,University of Technology, Sydney
ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) | Year: 2012

Increasingly electric vehicle design is looking forward the application of multiple ratio transmissions in place of traditional single ratio gearboxes. The choice of gear ratio has significant influence on vehicle performance, including range, acceleration, and gradeability. To study the impact of different transmissions on EV's dynamic and economic performance, mathematical models of an EV is presented which is applicable to both single and multiple ratio transmissions. These transmission variants are then studied under different operating conditions to investigate how operating conditions in the motor work efficiency change with different transmissions. Here comparisons are made between 2-speed and single speed transmission. Then the reasons for the results are analysed. Copyright © 2012 by ASME.


Xiang J.,Beijing Institute of Technology | Xiang J.,Beijing Electrical Vehicle Co. | Wu F.,Beijing Institute of Technology | Chen R.,Beijing Institute of Technology | And 2 more authors.
Journal of Power Sources | Year: 2013

Novel binary electrolytes based on ionic liquid (N-butyl-methyl piperidinium bis(trifluoro-methylsulfonyl)imide, PP14-TFSI) and sulfone (tetramethylene sulfone, TMS) have been prepared and examined for use in lithium-ion batteries. The addition of sulfone is expected to improve the lithium salts solvability, ionic conductivity and electrode compatibility of the ionic liquid greatly. More importantly, the addition of sulfone is not expected to deteriorate the peculiar properties of the ionic liquid, such as the wide electrochemical window and non-flammability. Experimental results have shown that the reversible discharge capacities of the Li/LiFePO4 half-cell, which contains a 0.5 M LiTFSI/(60%) PP14-TFSI/(40%) TMS mixed electrolyte at a current density of 0.05 C and 1 C, can reach up to 160 and 150 mAh g-1, respectively, which are much higher than the discharge capacity achieved using the pure ionic liquid electrolyte under the same conditions. Furthermore, lithium difluoro(oxalato)borate (LiDFOB) has been found to have positive effects on the battery performance of the mixed electrolytes. The 0.5 M LiDFOB/(60%) PP14-TFSI/(40%) TMS mixed electrolyte exhibits better compatibility with the Li1.2Ni0.2Mn 0.6O2 cathode than conventional electrolytes, where an initial discharge capacity of 255 mAh g-1 is obtained and a stable capacity of above 230 mAh g-1 is retained after 30 cycles. © 2013 Elsevier B.V. All rights reserved.


Yu H.,Beijing Electrical Vehicle Co. | Sheng J.,Beijing Electrical Vehicle Co. | Wang Y.,Beijing Electrical Vehicle Co.
IEEE Transportation Electrification Conference and Expo, ITEC Asia-Pacific 2014 - Conference Proceedings | Year: 2014

This paper presents a method to optimize the on-board energy system of electric vehicle in the aspect of electro-load characteristics. LiMn2O4 Battery (14.8V 100Ah) is used as low voltage energy system instead of the original lead-acid battery (12V 70Ah). The power battery system is divided into two parts, which are placed under the vehicle chassis and in the car trunk, respectively. The power battery system and low voltage energy system can be charged with the on-board charger. The low voltage battery charging is also optimized by solar cell in order to save energy. © 2014 IEEE.


Sun B.,Beijing Jiaotong University | Jiang J.,Beijing Jiaotong University | Han Z.,Beijing Jiaotong University | Han Z.,Beijing Electrical Vehicle Co. | And 2 more authors.
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2016

Lithium power battery is usually impacted by low temperature in a particular situation, and its low temperature stress is different with that in initial condition. Taken 35 Ah composite battery as an example, work range of the battery was divided by the transformation curve of the incremental capacity analysis based on different reaction stages of battery charging and discharging process. By aging the batteries at different SOC range, this paper traced the changes of electrochemical properties and analyzed degradation mechanism. Under 0℃ environment, the stress differences under low temperature of batteries which were degraded through different paths, was analyzed using C/3, 1C, 3C/2, 2C and 5C/2 currents to impact the aging cells by charging and discharging respectively. The result showed that the power battery produced obviously different degradation paths when it cycled at different SOC ranges. There is no mapping relation and consistency between low temperature degradation and cycling degradation. The conclusion provides the basis for battery pack lifetime analysis and second battery matching. © 2016, The editorial office of Transaction of China Electrotechnical Society. All right reserved.


Zhou X.,University of Technology, Sydney | Walker P.,University of Technology, Sydney | Zhang N.,University of Technology, Sydney | Zhu B.,Beijing Electrical Vehicle Co. | Ruan J.,University of Technology, Sydney
SAE Technical Papers | Year: 2014

This paper mainly studies the power losses in a refined two-speed dual clutch transmission which is equipped in a electric vehicle test rig. Both numerical and experimental investigations are carried out. After theoretical analysis of the power losses original sources, the developed model is implemented into simulation code to predict the power losses. In order to validate the effectiveness of the proposed model, results from experimental test are used to compare the difference the simulation and test. The simulation and test result agree well with each other. Results show that the power losses in the two-speed are mainly generated by multi-plate wet clutch drag torque and gear churning loss. Copyright © 2014 SAE International.


Wang A.-J.,Beijing Institute of Technology | Wang A.-J.,Beijing Electrical Vehicle Co. | Ge Y.-S.,Beijing Institute of Technology | Tan J.-W.,Beijing Institute of Technology | And 4 more authors.
Journal of Beijing Institute of Technology (English Edition) | Year: 2011

A total of 14 in-use diesel buses were selected to conduct emission measurement using a portable emissions measurement system (PEMS) in Beijing. Their instantaneous gaseous emission rates, particular matter (PM) emission rates and driving parameters were obtained. The influences of speed, acceleration and vehicle specific power (VSP) on emissions were analyzed. Based on the relationships between these driving parameters and emissions, 24 driving bins defined by speed, acceleration and VSP were constructed with cluster analysis to group emission rates for Euro III and IV buses, respectively. Then the emissions reductions from Euro III to Euro IV diesel buses were analyzed. Lastly, on-road hot-stabilized emission rate model for diesel buses in Beijing was developed. Through the comparison of the model simulation emission rates with the measured emission rates, the modeled emission results were in good agreement with the measured emission results. In most of the cases, the differences were less than 12%. © Copyright.

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