Beijing Research Institute of Precise Mechanical and Electronic Control Equipment

Beijing, China

Beijing Research Institute of Precise Mechanical and Electronic Control Equipment

Beijing, China
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Song M.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment | Pei P.,Tsinghua University
Qiche Gongcheng/Automotive Engineering | Year: 2014

A shutdown experiment is conducted on two stacks of proton exchange membrane fuel cell (PEMFC) after continuous operation to study the effects of shutdown with different ways on the performance of fuel cell. The results show that a short time of shutdown after continuous operation has a positive effect on the performance recovery of fuel cell, but a long period of shutdown may lead to performance degradation with significant discrepancy between pieces of fuel cell. Sealing measure may mitigate this adverse effect, but the unrecoverable performance decay is still hard to avoid. Rapid discharge after shutdown has a similar effect as that of short period of shutdown. ©, 2014, Qiche Gongcheng/Automotive Engineering. All right reserved.


Yan H.,Harbin Institute of Technology | Yu B.,Harbin Institute of Technology | Xiao C.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment | Song Z.,Harbin Institute of Technology | And 2 more authors.
2011 International Conference on Electrical Machines and Systems, ICEMS 2011 | Year: 2011

This paper investigates a novel tubular transverse-flux permanent-magnet linear machine (TFPLM) for a free-piston energy converter, which has advantages in efficiency, emissions and reliability for serial hybrid electric vehicles. Most importantly, the novel structure solves the problems of low power factor and complex process which exist in conventional transverse-flux permanent-magnet machines (TFPMs). In this paper, a staggered structure is applied for the adjacent stator teeth of a transverse-flux machine. This kind of structure has two topologies: three phases in the axial direction and three phases in the circumference direction. To minimize flux leakage, stator and permanent magnet dimensions are optimized by three-dimensional finite-element method (3-D FEM). As the key technology of TFPMLM, the method to increase power factor and force density has been investigated. And low thrust fluctuation, high power factor and force density are achieved by further optimization. The simulation results prove that the machine has both higher power factor and high efficiency. © 2011 IEEE.


Shi W.,Harbin Institute of Technology | Xiao C.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment | Lei Y.,Harbin Institute of Technology | Yu B.,Harbin Institute of Technology | And 2 more authors.
2011 International Conference on Electrical Machines and Systems, ICEMS 2011 | Year: 2011

This paper focuses on decreasing the thrust ripple of an axial-flux permanent-magnet linear synchronous machine (PMLSM) used for free-piston Stirling engines. A typical 1kW machine with 10 poles and 9 slots is investigated. By finite-element method (FEM), detent force and thrust ripple are analyzed for different axial and radial dimensions of the end stator tooth. Meanwhile, the similar trends of no-load detent force and load thrust ripple has been found. To verify the proposed method, prototype machine was manufactured and tested. © 2011 IEEE.


Zang Q.,Beijing Institute of Technology | Huang J.,Beijing Institute of Technology | Liang Z.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment
IEEE/ASME Transactions on Mechatronics | Year: 2015

Control of a moving liquid container is challenging because of unwanted transient and residual slosh. Although significant progress has been achieved at eliminating the fundamental sloshing mode, less success has been achieved with designing a controller to suppress slosh for an infinite number of modes. This study presented two methods to reduce an infinite number of sloshing modes in a moving liquid container. The first method is command smoothing to eliminate slosh by using the first-mode frequency. The second one is a combined input-shaping and command-smoothing architecture. The input shaper reduces slosh for the first mode, while the command smoother suppresses slosh for the third and higher modes. Both the command smoothing and the combined control scheme eliminate the transient and residual slosh to a very low level. However, the rise time of the combined controller is shorter than that of the command smoother. Simulations of a large range of motions are used to analyze liquid sloshing dynamics by using the proposed methods. Experimental results obtained from a moving container validate the simulated dynamic behavior and the effectiveness of the methods. © 2014 IEEE.


Huang J.,Beijing Institute of Technology | Liang Z.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment | Zang Q.,Beijing Institute of Technology
Mechanical Systems and Signal Processing | Year: 2015

Motion-induced oscillations of crane payloads seriously degrade their effectiveness and safety. Significant progress has been achieved with reducing payload oscillations on a single-pendulum crane with a point-mass payload attached to the end of the cable. However, large payloads and the actual configuration of the hoisting mechanism may transform the crane to a double-pendulum system with a distributed-mass payload. The manipulation task can be more challenging because of the complicated dynamics. The dynamics of bridge cranes transporting distributed-mass beams are derived. A command-smoothing scheme is presented to suppress the complex payload oscillations. Simulations of a large range of motions are used to analyze the dynamic behavior of the cranes and the robustness of the method. Experimental results obtained from a small-scale double-pendulum bridge crane transporting a distributed-mass beam validate the simulated dynamic behavior and the effectiveness of the method. © 2014 Elsevier Ltd.


Huang J.,Beijing Institute of Technology | Xie X.,Beijing Institute of Technology | Liang Z.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment
IEEE/ASME Transactions on Mechatronics | Year: 2015

Motion-induced oscillations of crane payloads seriously degrade their effectiveness and safety. For the transport of a large object, the payload is modeled as a distributed-mass model, and is typically attached to the hook by four rigging cables. The manipulation task can be more challenging because of the payload swing toward the driving direction and the payload twisting about the rigging cables. The dynamics of bridge cranes transporting distributed-mass payloads are derived. A control scheme is designed for suppressing both the payload swing and twisting. Simulations of a large range of motions and various system parameters are used to analyze the dynamic behavior and the robustness of the control scheme. Experimental results obtained from a bridge crane transporting distributed-mass crate validate the simulated dynamic behavior and the effectiveness of the control scheme. © 2014 IEEE.


Chen Y.,Tianjin University | Zheng J.,Tianjin University | Wei J.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment | Zheng Z.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment | Guo X.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2015

According to high power permanent magnet synchronous motor (PMSM) characteristics of low rotational inertia, high power density and short-time duty type, the paper presents reasonable selection of stator winding forms and coordination of slots and poles, and determines the basic size of motor. The motor shows high electrical performance with finite element analysis of the electromagnetic field. Temperature rise of the motor is serious due to its high power density, slender electromagnetic effective fraction and high rotational speed. On the basis of heat transfer theory, the solving model of 3D transient temperature field for PMSM is established and surface heat transfer coefficients are given. Stator winding copper loss, stator core iron loss, permanent magnet eddy loss and eddy loss in the rotor sheath are obtained by finite element analysis. Wire in stator slot and end region is equivalent into several heat conductors which distributed and arranged respectively, and more reliable 3D transient temperature distribution is obtained. Experimental results show that the design of motor is reasonable. ©, 2015, The editorial office of Transaction of China Electrotechnical Society. All right reserved.


Li K.,CAS Technical Institute of Physics and Chemistry | Li K.,University of Chinese Academy of Sciences | Xiao C.,Beijing Research Institute of Precise Mechanical and Electronic Control Equipment | Dai W.,CAS Technical Institute of Physics and Chemistry | And 3 more authors.
Proceedings of the 26th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2013 | Year: 2013

Free-piston Stirling engine has been extensively studied due to its high efficiency and fuel flexibility. As a kind of external combustion engine, heat transfer at the hot end has a great influence on the engine efficiency. In order to gain higher efficiency and configuration flexibility, a heater head structure with NaK liquid metal for heat transportation was numerically investigated based on the 1 kWe class Stirling engine in our lab. Firstly, through theoretical calculation, it was found that the heat conduction through the stainless steel wall causes a major temperature difference for heat transfer in heater head of the original configuration. With the concept studied here, the heat transfer temperature difference could be much reduced. Secondly, flow velocity and temperature fields were obtained to investigate the non-uniformities of flow and heat transfer in NaK passages. In order to suppress these non-uniformities which influence the engine performance, a dual opposed NaK outlet manifolds design was selected. Meanwhile, a finite element analysis was also performed to investigate the internal stress to check the structural strength of the heater head. The results show that this heater head design can effectively reduce the heat transfer temperature difference without sacrificing the structural strength. The study provides us a useful reference for designing liquid metal heat exchanger for free piston Stirling engines in the future.

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