Zhao Q.,Sichuan University |
Ding Y.,Sichuan University |
Yang B.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Ning N.,Sichuan University |
Fu Q.,Sichuan University
Polymer Testing | Year: 2013
A unique ultrafine full-vulcanized powdered ethyl acrylate rubber (EA-UFPR) was used as the toughening modifier for poly (lactic acid) (PLA). Largely improved tensile toughness was successfully achieved with the incorporation of only 1 wt% EA-UFPR, while the tensile strength and modulus of the blends were almost the same as pure PLA. The highly efficient toughening of PLA by UFPR is mainly ascribed to the strong interfacial interaction between PLA and UFPR and good dispersion of UFPR particles in PLA matrix. Our work provides an effective toughening method to largely improve the mechanical properties of PLA without sacrificing its stiffness, which is very important for the wide application of PLA materials. Crown Copyright © 2012 Published by Elsevier Ltd. All rights reserved.
Lu Y.,Wuhan University of Technology |
Yi J.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Lv Z.,Wuhan University of Technology
ICTIS 2015 - 3rd International Conference on Transportation Information and Safety, Proceedings | Year: 2015
Based on the safety evaluation model, risk offsetting factors of the dangerous cargo ship are analyzed. Correlation algorithm of the control factors of the maximum accident rate offset and algorithm of comprehensive offsetting factors are given. Combined with statistical analysis of inland ship accidents, the differences between the value of the inherent risk evaluation and the real risk evaluation have been compared. According to data analysis, the curves between each offsetting factors and safety evaluation values are obtained. The ship risk evaluation is determined accurately. The negative feedback mechanism of the ship safety management to the risk has been obtained. © 2015 IEEE.
Wang W.-A.,Central South University |
Wang W.-A.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Gui W.-H.,Central South University
Tiedao Xuebao/Journal of the China Railway Society | Year: 2013
In order to solve the negative sequence current problem caused by high-speed and heavy-load locomotives for two phase traction power supply systems and to surpress harmonics and compensate reactive power, considering the advantage of a Modular Multilevel Converter (MMC) able to be directly applied in middle and high voltage systems without the need for an input transformer, the multilevel railway static power conditioner (MRPC) of half bridge modules-cascaded type was put forward, which consisted of two back-to-back power converters to achieve two phase transmission of active power. Appropriate power conversion eliminated or reduced negative sequence currents in the high voltage system and compensated the reactive power and harmonics in the feeding lines that connected to the converters. The presence of high voltage and small current on the DC side of the converter avoided the difficulty of heat dissipation caused by large direct currents. In the context of a traction substation installed with the Scott transformer, the structure, the operating principle and detection and control of active power, reactive power and harmonics of the MRPC system were analyzed. A five-level prototype was established. The effectiveness and feasibility of the proposed MRPC system was proved by experiment results.
Jing H.,Central South University |
Nian X.,Central South University |
Luo W.,CSR Zhuzhou Electrical Locomotive Research Institute Co.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012
DC side of VSC-HVDC station is connected directly, and the dc voltage regulating is also inter coupling with power control. The situation of transmission line icing is existed simultaneously. Based on the analysis of the existing VSC-HVDC station, a VSC-HVDC chopping converter station with ice-melting function was proposed. The converter station adopted the style of cascade VSC units, and used a chopper to control the voltage difference between two-terminal converter station in DC side to control the transmission power. It can be used as DC ice-melting power on transmission line. On the basis of the analysis of converter station's circuit topology with chopping transmission function in DC side, the mathematical model and equivalent circuit of a converter unit was obtained; with the operation states classification, the control strategy of the VSC-HVDC chopping converter station was researched. The control method under different operation modes was discussed, and the test prototype was manufactured. The test results show that the converter station can be applied to the middle and small VSC-HVDC and ice-melting of the power line respectively; the station can achieve the function of DC-chop transmission and DC ice-melting. The results also verify the correctness and effectiveness of the theoretical analysis and the system. ©2012 Chin. Soc. for Elec. Eng.
Zhang D.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Wang W.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Liu H.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Qiu Y.,CSR Zhuzhou Electrical Locomotive Research Institute Co.
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2013
In order to synchronous compensate the reactive power, harmonics and negative sequence current in high voltage distribution network considering the predominance of active and passive compensators, a low-cost hybrid dynamic suspended compensation system constituted by a large capacity, sixpenny static var compensator (SVC) based on thyristor controlled reactor (TCR) and a small capacity, quick response chain-link static var generator (SVG) is proposed. The former is used to compensate slow-change reactive power and negative sequence current, and the latter is used to compensate for the error of SVC and loads, and suppress harmonics synchronously. The capacity allocation and the active capacity calculation are deduced by experiences. For the sake of promoting harmonics suppression, a synergetic control strategy of SVC and SVG is proposed by rules and voltage fluctuate forecast based on artificial neural network. The proposed system is used in arc furnaces, and the effectiveness and feasibility are proved by comparing the dominating power quality parameter data before and after the system put into operation.
CSR ZHUZHOU Electrical LOCOMOTIVE RESEARCH INSTITUTE CO. | Date: 2013-12-16
A direct-axis current protection method and device for a permanent magnet synchronous motor drive system. The method includes: pre-calculating the direct-axis current of the next moment according to the current voltage transmitted from an inverter to a permanent magnet synchronous motor (PMSM); comparing the direct-axis current of the next moment with a maximum protection current; if the direct-axis current of the next moment is less than the maximum protection current, continuing transmitting the current voltage to the PMSM; if the direct axis current of the next moment is greater than or equal to the maximum protection current, redistributing the voltage according to a protection direct-axis current and a protection quadrature-axis current, and transmitting the redistributed voltage to the PMSM. The direct-axis current of the next moment is tended to be normal by adjusting the voltage.
CSR ZHUZHOU Electrical LOCOMOTIVE RESEARCH INSTITUTE CO. | Date: 2013-12-16
A driving system for a multi-energy power supply motor comprises a distributed power supply, a frequency converter, a public power grid, and a motor load. The distributed power supply is connected to a direct-current bus of the frequency converter, and is used for acquiring and transmitting a direct current to the frequency converter. The frequency converter comprises a first bidirectional current transformer, an inverter, and a direct-current bus. The first bidirectional current transformer is connected to the inverter through the direct-current bus. The first bidirectional current transformer is connected to the public power grid. The inverter is connected to the motor load. The distributed power supply, the public power grid and the motor load are separately connected to the frequency converter.
Sheng K.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Wang D.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Wang L.P.,CSR Zhuzhou Electrical Locomotive Research Institute Co.
Advanced Materials Research | Year: 2014
The turbulence intensity is an important parameter in wind energy resource assessment, and is the main basis of the wind turbine design and equipment shaping. This paper introduces the methods of turbulence intensity calculation, especially the method based on turbulence transport models in CFD. The CFD method of Meteodyn WT is applied to calculate turbulence intensity of wind farm site in complex terrain of some area, and the simulation is compared with measured date by the mast and the simulation based on the line model. The results show that CFD method of Meteodyn WT provides good results of turbulence intensity. It is significant that the CFD method is applied in wind resource assessment and micrositing of wind farm. © (2014) Trans Tech Publications, Switzerland.
CSR Zhuzhou Electrical Locomotive Research Institute Co. | Date: 2013-12-16
A control method for restarting a permanent magnet synchronous motor (PMSM) in a rotating condition, and a device and a system thereof are provided. In the method, an electrical angular speed _(e )of the PMSM is obtained based on a speed of a trailer to obtain a back electromotive force of the PMSM. The back electromotive force is compared with a voltage at a side of an inverter, and if the electromotive force of the permanent magnet synchronous motor is higher than the voltage at the side of the inverter, the restarting of the PMSM is forbidden, otherwise, the restarting of the PMSM is allowed. Therefore, in the present disclosure, the low-speed operating condition and the high-speed operating condition correspond to different position angles of the rotor, and the PMSM is started based on the position angle of the rotor.
Jing H.,CSR Zhuzhou Electrical Locomotive Research Institute Co. |
Jing H.,Central South University |
Nian X.,Central South University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2013
In light of the lower performance-price ratio of the ice-melting device and the relatively strong periodicity in its application, a hybrid high power DC ice-melting source with static synchronous compensator (STATCOM) function is put forward. Based on analysis of topology operation principle and operation switching process, the equivalent circuit and mathematical model of power unit and main circuit are deduced on the condition of STATCOM and DC ice-melting application. Modulation strategy, unit operation mode and control method are studied under STATCOM and DC ice-melting mode, and a new way for the unit balance is given. Simulation and test results show that this hybrid high power DC ice-melting source has better reactive power compensation and DC ice-melting effects. Consistent with the analysis, the results also verify the correctness of topology and control method. © 2013 State Grid Electric Power Research Institute Press.