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Zhang D.,Beijing Institute of Technology | Xiang C.,National Key Laboratory of Vehicular Transmission | Han L.,Beijing Institute of Technology
Lecture Notes in Electrical Engineering | Year: 2013

The tri-mode power-split transmissions, compared with the single-mode and dual-mode ones, can further optimize the operating point of the engine, make full use of the characteristics of the motor/generator and improve the driving performance and the fuel economy of the vehicles. As the structure of tri-mode systems is more complex, it is difficult to apply the design method of single-mode or dual-mode systems in the tri-mode ones. Therefore, it is quite necessary to further study the method of design and performance prediction of tri-mode power-split transmissions. The design method of power-split transmissions based on ideal driving performance and the operating characteristics of the components was put forward, and a tri-mode power-split transmission was designed. The optimal parameter matching method was developed by taking the driving performance, fuel economy and cost as optimization objective, the feasible schemes as research object and the system parameters and control parameters as optimized variables. Then, based on MATLAB and Simulink, a performance prediction method was provided and the steady-state performance and dynamic performance of the power-split transmission was predicted. © Springer-Verlag 2013.

Tang T.,Beijing Institute of Technology | Liu H.,National Key Laboratory of Vehicular Transmission | Han L.J.,Beijing Institute of Technology
Advanced Materials Research | Year: 2014

In this paper, a mode control strategy for a two-mode EVT hybrid electric vehicle (HEV) is proposed,considering transmission efficiency and mode change quality. First,speed and torque characteristics are analyzed by establishing relevant equations of two transmission mode. Next,the optimal operation mode is selected from the viewpoint of the transmission efficiency,when it is higher at a given speed ratio.Then,two scheme of operation sequence of clutch/brake are compared,and a control algorithm of synchronous control of two MGs and engine is suggested to reduce speed difference between both end of the clutch and torque fluctuation. A vehicle simulation based on Matlab/Simulink was performed to testify the mode change control algorithm of the dual-mode EVT HEV,and the simulation results showed that the mode control strategy for the dual-mode EVT HEV gave acceptable performance. © (2014) Trans Tech Publications, Switzerland.

Peng Z.-X.,Beijing Institute of Technology | Hu J.-B.,National Key Laboratory of Vehicular Transmission | Xie T.-L.,Beijing Institute of Technology | Liu C.-W.,Beijing Institute of Technology
Journal of Mechanical Design, Transactions of the ASME | Year: 2015

To obtain multiple speed ratios, a synthesis methodology of planetary gear trains (PGTs) with multiple operating degrees-of-freedom (DOFs) is proposed based on the variable structure method. Variable structure of PGT is accomplished by changing the fixed interconnection edge. First, PGTs with two operating DOFs are synthesized with a deduction method based on the relationship between the number of planetary gear sets (PGSs) and number of fixed interconnection edges. Next, connection characteristics of fixed interconnection edges are defined as frequency of utilization to construct original speed ratios of the two operating DOFs schemes. The connection characteristics are then obtained based on the power flow analysis. PGT graph model with connection characteristic is built to provide guidance in the design of varying structure. Finally, multi-speed PGTs with multiple operating DOFs are synthesized based on the graph model and lever analogy. A design example for three-PGS PGTs is considered to highlight capabilities of the variable structure method. Copyright © 2015 by ASME.

Zhang D.,Beijing Institute of Technology | Xiang C.,Beijing Institute of Technology | Xiang C.,National Key Laboratory of Vehicular Transmission | Han L.,Beijing Institute of Technology | And 2 more authors.
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2015

To solve the optimal control problem of HEVs during the dynamic process, a dynamic control strategy was proposed based on drivability optimization. A control-oriented dynamic power distribution model was established according to the characteristics of the power-split hybrid electric system. Based on the driver's expected status and the vehicle's actual status, the index function of the drivability was come up with. A control strategy satisfying the drivability was presented firstly. The dynamic characteristics of the different components and the speed tracing requirements of the engine were fully considered in the optimization model. Additionally, a real-time optimization algorithm of the drivability was proposed. It can be seen from the simulation results that this control method improves the drivability dramatically without scarifying the fuel economy. ©, 2015, China Mechanical Engineering Magazine Office. All right reserved.

Zhang D.,Beijing Institute of Technology | Xiang C.,Beijing Institute of Technology | Xiang C.,National Key Laboratory of Vehicular Transmission | Han L.,Beijing Institute of Technology | And 2 more authors.
IEEE Transportation Electrification Conference and Expo, ITEC Asia-Pacific 2014 - Conference Proceedings | Year: 2014

Electro-Mechanical Transmission (EMT), which is especially suitable for the heavy-duty vehicles, can transmit the engine's energy to the drive shaft by electrical and mechanical power paths so that it can improve the driving and fuel economic performance. The problem is how to split the power flow to achieve the best performance. The non-linear multi-objective optimization model was built and a hierarchic optimization algorithm was proposed. The feasibility and effectiveness of the algorithm was verified by the simulation results, which can also provide the basis for further development of the control strategy. © 2014 IEEE.

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