Wu S.-L.,Sichuan Electrical Power Design Institute |
Liu Y.-M.,Jiangxi Electrical Power Design Institute |
Hu J.,Tsinghua University |
Mao H.-C.,Beijing Construction Safety and Quality Supervision Station
Proceedings - 2015 International Conference on Intelligent Transportation, Big Data and Smart City, ICITBS 2015 | Year: 2015
We researched the permeability of different mix proportion.We compared the grading curve of the optimal grading by theoretical calculation (including aggregate and gelled material) and there mixture ratio of test.And we compared the permeability of different mixture ratio.We draws the following conclusions: Permeability of concrete with long age has close relationship with gradation including aggregate and gelled material. Dosage of mineral admixtures has no big effect on permeability, while the proportion of different mineral admixture has big.The limestone powder content had the greatest influence to permeability by gradation, so increasing its content instead part of cement within certain range could increase the ability of permeability resistance. © 2016 IEEE.
Chen J.-Y.,Shanghai JiaoTong University |
Fan C.-J.,Shanghai JiaoTong University |
Liu L.,Jiangxi Electrical Power Design Institute
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011
To solve the problem that the traditional longitudinal differential protection used in four-circuit transmission line on the same pole with different levels will be seriously affected by coupling inductance, a new longitudinal differential protection scheme based on inverse-sequence negative sequence difference current is proposed. Four-circuit transmission lines with different voltage grades generally consist of two double circuit transmission lines at the same tower. However, when line parameters are symmetry, the inverted sequence current is zero when the system operates normally or external faults occur. Once internal faults occur, there is inverted current in the transmission line, and the sum of inverted current at both sides is large, so the differential protection based on inverted current can operate correctly. For this method, the reliability and sensitivity under big fault resistance can be kept. And it will not be affected by capacitive current when it is applied to the main protection of four-circuit transmission line with different voltage grades. The theoretical analysis and EMTP simulation results show that the proposed principle is correct and reliable.
Zhao L.,NARI Group |
Wang M.,Jiangxi Electrical Power Design Institute |
Ni M.,NARI Group |
Li X.,NARI Group
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2016
The reliability of security and stability control device is important to the operation of electric power grid. Taking SCS-500E which is one kind of security and stability control device for example, the components and their logical relationship in the hardware system of the device are analyzed. Based on the analysis, the fault tree model and the Markov state space model are built by fault tree method and Markov state space methodology. The paper believes that the device has 4 operation states which are normal operation, hidden mal-operation, hidden anti-operation, and outage. The probabilities of the 4 operation states are got by fault tree model and the Markov state space model. Other reliability indexes of the hardware system of the device which are availability, hidden failure probability, and probability of outage caused by hidden failure are also delimited. It is proved that the results worked by the method proposed in the paper are matched with the actual facts and the method is correct. © 2016, Power System Protection and Control Press. All right reserved.
Li L.,Hebei University of Technology |
Li L.,National Chin - Yi University of Technology |
Han Y.,Hebei University of Technology |
Chen W.,National Chin - Yi University of Technology |
And 3 more authors.
PLoS ONE | Year: 2016
In this paper, an improved algorithm of wavelet packet-chaos model for life prediction of space relays based on volterra series is proposed. In the proposed method, the high and low frequency time sequence components of performance parameters are obtained by employing the improved wavelet packet transform to decompose the performance parameters of the relay into multiple scales. Then the optimization algorithm of parameters in volterra series is improved, and is used to construct a chaotic forecasting model for the high and low frequency time sequence components gained by the wavelet packet transform. At last, the chaotic forecasting results of the high and low frequency components are combined by taking the wavelet packet reconstruction approach, so as to predict the lifetime of the studied space relay. The algorithm can predict the life curve of the relay accurately and reflect the characteristics of the relay performance with sufficient accuracy. The proposed method is validated via a case study of a space relay. © 2016 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Tong X.,Southwest Jiaotong University |
Liao C.,Southwest Jiaotong University |
Zhou L.,Southwest Jiaotong University |
Li Y.,Jiangxi Electrical Power Design Institute |
And 3 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010
The communication capability of Ethernet is a key for normal operation of digital substation automation system based on IEC 61850. Aiming at the united ring and star networks in whole substation, the simulation software OPNET is adopted to construct the mathematical models of various typical data flow in this paper. IEC 61850-9-2 protocol is used to transfer the sampling values. A variety of simulating test schemes are made, which consider following factors such as: structure and bandwidth of network, the different transferring of sampling values by the process network, the breaking failure of the ring network, the influence of file transferring on the sampling values and tripping message. The results of simulating experiments for an actual medium-size substation are given. It provides a reference for construction of a digital substation system. ©2010 State Grid Electric Power Research Institute Press.
Ye M.,East China Jiaotong University |
Cai H.,Jiangxi Electrical Power Design Institute |
Song P.,East China Jiaotong University
Gaodianya Jishu/High Voltage Engineering | Year: 2016
In order to solve the problem that the input source of distributed generator system usually varies in a large scale, a new 3-switch single-stage single-phase buck-boost inverter is proposed. The inverter can meet a wide input voltage range with independent load operation and power grid operation, and it has the least switch, simple control, and high efficiency. By analyzing each working mode equivalent circuit and mathematical modeling, we compare the difference between discontinuous conduction mode(DCM) and continuous conduction mode(CCM) control mode, deduce the AC small signal model by DCM, and put forward a new closed-loop SPWM control strategy. The simulation and experimental results verify that this topology can operate under standalone and grid-connected when input voltage varies from 50 V to 300 V. Furthermore, output current waveforms can satisfy the requirements of grid, and the efficiency of whole inverter exceeds 90%. © 2016, High Voltage Engineering Editorial Department of CEPRI. All right reserved.
Zuo L.-X.,East China Jiaotong University |
Ding Q.-F.,East China Jiaotong University |
Wu P.,JiangXi Electrical Power Design Institute
WIT Transactions on Information and Communication Technologies | Year: 2014
The on-line insulation monitoring device of high voltage electrical equipment has played an important role in the intelligent substation; the performance of a signal acquisition system directly affects the accuracy and reliability of the whole device. In this paper, a data acquisition system based on DSP and AD7656 is designed. The design of hardware interface circuits and implementation of software is described. It is a comparatively new data acquisition system, which has high acquisition accuracy and flexible configuration. © 2013 WIT Press.
Chen X.,Wuhan University |
Hua X.,Wuhan University |
Jiang J.,Wuhan University |
Wei C.,Jiangxi Electrical Power Design Institute
Journal of the Indian Society of Remote Sensing | Year: 2014
The corresponding points are prerequisite to the registration of Terrestrial Laser Scanning data (TLS). The exceptional corresponding points will direct impact the quality of registration. The interest in this paper is in the so-called residuals iteration correction algorithm, which focused on a new procedure for correcting the exceptional corresponding points. The kernel of the procedure is the Affine proposed by Berger (1987). This paper describes the three main steps of residuals iteration correction algorithm based on Affine, namely the decomposition of exceptional corresponding points, the propagation of registration residuals, and the correction of exceptional corresponding points. The paper outlines the key advantages of the proposed approach, such as the capability to correct exceptional corresponding point automatically according to the point precision. Furthermore, it illustrates the performance of proposed approach with a validation experiment where two exceptional corresponding points were simulated and "3S" statue TLS data in Wuhan University was acquired. From the analysis of this experiment, the result shows that the validation of correction of exceptional corresponding points based on residuals iteration. © 2013 Indian Society of Remote Sensing.
Fu X.-Q.,Jiangxi Nanchang Power Supply Company |
Xu L.-Z.,Jiangxi Nanchang Power Supply Company |
Zhao B.-L.,Jiangxi Electrical Power Design Institute
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010
The paper expounds and analyses the technology principle about 10 kV grounding through small resistance. And it discusses the technology principle about choosing equipment. What's more, it summarizes the process and result of using the technology in 110 kV distribution system of Nanchang power grid and accumulates operation experience such as its influences on the reliability of power supply, the influence of fault instantaneous voltage and current on electrical equipment, the influence on comunnmunication and requirements for relay protection, etc.
Li Z.,South China University of Technology |
Wei Y.-C.,Jiangxi Electrical Power Design Institute
Huanan Ligong Daxue Xuebao/Journal of South China University of Technology (Natural Science) | Year: 2013
Cables of suspension bridges possess strong nonlinear characteristics under both static and dynamic forces, and, under the boundary excitation with certain frequency ratio, they may perform parametric vibration with the amplitude being much more than the initial value. In order to solve this problem, a parametric vibration model of suspender cable, which takes the bridge deck vibration as the boundary excitation and considers the first two order modals, was established. Then, by taking the super-large Aizhai suspension bridge as an engineering example, the first-order and the second-order parametric vibrations of the suspender cable under boundary excitation in the finished bridge state were analyzed, the same excited conditions and the response characteristics of parametric vibration of the suspender cable were determined by using the multi-scale method and the Runge-Kutta method, and the effects of excitation amplitude, cable length and initial disturbance on the resonant response amplitude were investigated. The results indicate that the suspender cable of long-span suspension bridges under deck vibration may perform a parametric vibration with the vibration ratio of 1:1 or 1:2, and that the excitation amplitude, the cable length and the initial disturbance affect the response amplitude and the response time to a certain degree.