Ling W.,Shanghai JiaoTong University |
Liu D.,Shanghai JiaoTong University |
Chen X.,Shanghai Municipal Electric Power Company |
Liu J.,East China Electric Power Test and Research Institute Co. |
He W.,Shanghai Municipal Electric Power Company
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2012
The feeder automation algorithm has the typical characteristics of discrete-type software. The reliability question has all along been one of the key restraining factors for large-scale application, being affected by various kinds of interference factors, including communication failures between system and site terminal unit, switch equipment refusing action, feeders changing its operation mode, and so on. This paper presents a failure-free evaluation test method for feeder fault location, isolation and restoration (FLISR) algorithm of reliability, and combines with Bayes identification test frequency selection method to determine test sample space. By averaging the test sample results on the user side of the contribution degree, the algorithmic reliability of quantitative score is obtained. Finally, an actual site of intelligence distributed feeder automation system is taken as an example for test, which verifies the effectiveness of the proposed reliability evaluation method. © 2012 State Grid Electric Power Research Institute Press.
Gao J.,Shanghai University of Electric Power |
Yang F.,East China Electric Power Test and Research Institute Co. |
Yang J.,Shanghai University of Electric Power |
Zhao H.,East China Electric Power Test and Research Institute Co.
Journal of Information and Computational Science | Year: 2011
IEEE 1588 precision time protocol is capable of providing accurate timing over local area network. It is a promising technology to be used in power industry, especially in the smart substations based on the IEC 61850 technologies. The accuracy of path delay measurement of a local clock has a direct impact on the accuracy of its synchronization with master clock. This paper investigates the effects of the frequency drift of local crystals oscillator on path delay measurement. A simple analytical form to estimate the maximum error of the measurement is derived. © 2009 by Binary Information Press.
Huang X.,Nanjing Southeast University |
Liu Z.,Wuxi Electrical Power Supply Company |
Zhu R.,East China Electric Power Test and Research Institute Co. |
Yang Z.,East China Electric Power Test and Research Institute Co. |
And 3 more authors.
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2010
The integration of large capacity wind farm may pose certain influence to power networks. This article introduces the model and control strategy of doubly-fed induction generator (DFIG) belonging to variable speed constant frequency (VSCF). The analysis of its operational characteristics confirms the facts that integration of large wind farm will impact power networks significantly, including frequency fluctuation, voltage deviation and fluctuations, deterioration of transient stability. Some measures for improvement are proposed. By the model of Nantong grid which is built in PSS/E. The emulation results demonstrate the correctness of the analysis above both in wind speed fluctuation and system fault.
Wang D.,NR Electrical Co. |
Zhou Q.,NR Electrical Co. |
Ding F.,NR Electrical Co. |
Deng J.,NR Electrical Co. |
Yang Z.,East China Electric Power Test and Research Institute Co.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2014
The phase shifter as an efficient measure of regulating the power flow by inserting compensation voltage has important significance for improving the utilization ratio of transmission lines, balancing system power flow, and etc. Based on the thyristor controlled double core symmetry phase shifter, a simple system model is built in the real time digital simulator (RTDS) and the control device is developed. In consideration of the influence of different firing angles, a control strategy is proposed. The firing pulse is advanced before current zero-crossing when the voltage tap is fixed and after current zero-crossing when the voltage tap is being regulated. And a detection method of current zero-crossing is also presented. The result shows that the system is stable and harmonic-free at the fixed voltage tap. The transition is smooth and short-current-free during voltage tap regulation.
Song J.,Shanghai University of Electric Power |
Gao L.,Shanghai University of Electric Power |
Bao W.,East China Electric Power Test and Research Institute Co. |
Shen B.,East China Electric Power Test and Research Institute Co. |
And 2 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012
GOOSE virtual terminal concept is proposed to help us to understand the way of smart substation SCD configuration. Aiming at the new features of GOOSE virtual terminal technology in smart substation, a new software test system is developed, which can not only be used to simulate the actual movement behaviors of the external protection system by importing CID (Configured IED Description) of relay-protection devices from different manufacturers, but also can test and debug the collaboration of variety of intelligent protection devices based on IEC61850 on line. GOOSE virtual terminal connection test on collaborative testing system is detailed. The feasibility and effectivity of the proposed scheme has been verified in the verification test in the integration tests of 220 kV Luding smart substation. It exhibits a broad application prospect.
Qian Z.-Y.,East China Grid Company |
Qian Z.-Y.,Xi'an Jiaotong University |
Xiao R.,East China Electric Power Test and Research Institute Co.
Gaodianya Jishu/High Voltage Engineering | Year: 2010
In this paper, the artificial pollution cycle test equipment was established. Nature conditions (pollution quantity, wind, rain, fog) which influence the pollution degree of the transmission line insulators were simulated artificially. The test conditions of artificial pollution cycle testing were confirmed on the base of analyzing climatic characteristics in East China and the artificial pollution cycle testing were performed on the insulators which frequently are used in East China, meanwhile long term pollution accumulated characteristics of these insulators were obtained. By comparison with the test data from nature pollution accumulated on online insulators, the equivalence of artificial pollution cycle testing was demonstrated.
Zhang X.,Leibniz University of Hanover |
Gockenbach E.,Leibniz University of Hanover |
Liu Z.,East China Grid Company |
Chen H.,East China Electric Power Test and Research Institute Co. |
Yang L.,East China Electric Power Test and Research Institute Co.
Electric Power Systems Research | Year: 2013
In order to estimate the reliability of high voltage SF6 circuit breakers, it is necessary to develop a statistical approach which can provide the failure probability, the failure rate and the remaining lifetime for the equipment and components. Useful information about the failure occurrences of 550 kV SF6 circuit breakers is collected from the East China Grid with the operating history. Even if the statistical survey is linked to data records of the unfailed components and maintenance measures, the statistical approach can accurately estimate the reliability of the components assembled in the circuit breakers. It is demonstrated by individual characteristics of 550 kV SF6 circuit breakers such as N2 leakage, SF6 leakage, overheat of primary terminal and defect of protection- and control system, etc. that the statistical approach is able to assess the reliability of equipment and components with reasonable and accurate results. © 2013 Elsevier B.V. All rights reserved.
Lu Y.,Wuhan University |
Lu Y.,State Grid Electric Power Research Institute of China |
Qi X.-M.,East China Electric Power Test and Research Institute Co. |
Zhang G.-Z.,Wuhan University |
And 4 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2010
The audible noise of DC transmission lines is different from that of AC transmission line and has no extruding component but a wide band. Therefore, studying the characteristics of the audible noise from the transmission line is very important for the prediction of audible noise of successor power transmission project. We measured the audible noise near the DC transmission lines that have the same voltage and different section. The frequency spectra of the audible noise of the DC transmission line were provided. The influence of other nature phenomena on the frequency spectrum of audible noise was analyzed. The results show that: audible noise from conductor of different section differs greatly; audible noise from ±500 kV DC operating lines is less than the limit of area of class 0(for example, villa, health resort); the wind noise will impact the low frequency part of the spectrum; the insect's singing in the daytime will impact the high level of the spectrum.
Zhang B.,Shanghai JiaoTong University |
Zhang Y.,Shanghai JiaoTong University |
Li L.,Shanghai Municipal Electric Power Company |
Chi F.,East China Electric Power Test and Research Institute Co.
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2012
The reliability assessment based on connection point analysis is proposed to more comprehensively estimate the reliability level of transmission system. The definition of connection point and its identification, as well as the assessment index system of transmission system and its calculation formulas, are introduced. It collects the outage information of connection points in the system and calculates the related statistical indices to reflect the power supply capability transmission system. The momentary outage is considered and the trend of reliability change is reflected by the tendency index. Its effectiveness and practicability are verified by case study, which shows the influence of system structure on system reliability in the comparison of reliability condition between different transmission systems.
Gu C.-Y.,East China Electric Power Test and Research Institute Co. |
Si W.-R.,East China Electric Power Test and Research Institute Co. |
Zheng X.,East China Electric Power Test and Research Institute Co. |
Zhao W.-B.,East China Electrical Power Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2012
The mechanism of DC bias and the DC bias suppression equipments at transformer neutral point are described. Considering the feature of many DC grounding electrodes in Shanghai region, a method for suppressing DC bias using parallel connection of DC grounding electrodes is proposed. The DC grounding electrodes in Fengxian, Huaxin and Nanqiao 500 kV substations are modeled, and equivalent resistances for each substation are obtained according to the primal construction data. And a four-layer horizontal soil model is established including superficial sedimentary deposit, deep sedimentary deposit, bedrock deposit and earth mantle deposit by considering the geologic frame and the measured resistivity of different soil layer in Shanghai region. The earth potential and DC bias current of transformers in Shanghai region are calculated and analyzed in the cases of independent operation and parallel-connection operation of the DC grounding electrodes with the topological structure of the existing Shanghai power grid. The results show that the earth potential and DC bias current of each 500 kV-level substations can be efficiently suppressed.