Zhe Zhang
Huazhong University of Science and Technology

Published : 7 Documents
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Architecture and Fault Identification of Wide-area Protection System Li, Zhenxing; Yin, Xianggen; Zhang, Zhe; Wang, Yuxue
TELKOMNIKA Telecommunication, Computing, Electronics and Control Vol 10, No 3: September 2012
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (51.295 KB)

Abstract

Wide-area protection system (WAPS) is widely studied for the purpose of improvng the performance of conventional backup protection. In this paper, the system architecture of WAPS is proposed and its key technologies are discussed in view of engineering projects. So a mixed structurecentralized-distributed structure which is more suitable for WAPS in limited power grid region, is obtained based on the advantages of the centralized structure and distributed structure. Furthermore, regional distance protection algorithm was taken as an example to illustrate the functions of the constituent units. Faulted components can be detected based on multi-source imformation fuse in the algorithm. And the algorithm cannot only improve the selectivity, the rapidity, and the reliability of relaying protection but also has high fault tolerant capability. A simulation of 220 kV grid systems in Easter Hubei province shows the effectiveness of the wide-area protection system presented by this paper.
Architecture and Fault Identification of Wide-area Protection System Li, Zhenxing; Yin, Xianggen; Zhang, Zhe; Wang, Yuxue
TELKOMNIKA Indonesian Journal of Electrical Engineering Vol 10, No 3: July 2012
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/telkomnika.v10i3.604

Abstract

Wide-area protection system (WAPS) is widely studied for the purpose of improvng the performance of conventional backup protection. In this paper, the system architecture of WAPS is proposed and its key technologies are discussed in view of engineering projects. So a mixed structure—centralized-distributed structure which is more suitable for WAPS in limited power grid region, is obtained based on the advantages of the centralized structure and distributed structure. Furthermore, regional distance protection algorithm was taken as an example to illustrate the functions of the constituent units. Faulted components can be detected based on multi-source imformation fuse in the algorithm. And the algorithm cannot only improve the selectivity, the rapidity, and the reliability of relaying protection but also has high fault tolerant capability. A simulation of 220 kV grid systems in Easter Hubei province shows the effectiveness of the wide-area protection system presented by this paper.
Phase Current Differential Protection for Transformers in Wye-delta Mode Wang, Yuxue; Yin, Xianggen; Zhang, Zhe; Li, Zhenxing
TELKOMNIKA Indonesian Journal of Electrical Engineering Vol 10, No 6: October 2012
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/telkomnika.v10i6.1413

Abstract

For the current transformers (CTs) on the delta side measure the line current instead of the phase current, line current differential protection is adopted in transformers connected in wye-delta mode currently. However, the symmetry feature of inrush current in line current differential protection may invalidate the inrush current restrained criterion. A calculating method of current through delta windings according the measured current from CT is proposed in this paper. Using this calculated current, phase current differential protection can be realized. Based on the method an adaptive second harmonic restrained scheme for magnetizing inrush current is presented. The scheme not only adaptively adjusts the secondary harmonic ratio of restrained current but also guarantees the fast action when transformers with internal faults are no-load energized. Consequently the performance of transformer differential protection is greatly improved. Simulation results in Matlab/Simulink validate the proposed method.
A Novel Fault Phase Selector for Double-Circuit Transmission Lines Deng, Xing; Yin, Xianggen; Zhang, Zhe; Kong, Xiangping; Qiu, Cheng
TELKOMNIKA Indonesian Journal of Electrical Engineering Vol 10, No 7: November 2012
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/telkomnika.v10i7.1569

Abstract

A novel fault phase selector for double-circuit transmission lines is presented. The fault type is determined with the superimposed components and steady state components of fault voltage. According to the determined fault type, auxiliary criteria based on the magnitude and phase difference of fault phase current is applied to judge whether inter-line fault happens or not. If inter-line fault happens, the fault phase is determined by comprehensive criteria based on the comparison of current magnitude and the judgment of impedance direction. The simulation results verify the correction of the proposed phase selector.
Study on Fault Current of DFIG during Slight Fault Condition Kong, Xiangping; Zhang, Zhe; Yin, Xianggen; Li, Zhenxing
TELKOMNIKA Indonesian Journal of Electrical Engineering Vol 11, No 4: April 2013
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | 10.11591/telkomnika.v11i4.2542

Abstract

In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influence of controller parameters of converter on the fault current characteristics is analyzed emphatically. It builds a basis for the construction of relay protection which is suitable for the power gird with accession of DFIG.
Traveling-Wave-Based Fault Location in Electrical Distribution Systems With Digital Simulations Tang, Jinrui; Yin, Xianggen; Zhang, Zhe
TELKOMNIKA Telecommunication, Computing, Electronics and Control Vol 12, No 2: June 2014
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Traveling-wave-based fault location in electrical distribution systems is an important safeguard for the distribution network reliability. The effectiveness of the methods is verified directly in power grid in the early stages, while different fault types cant appear in a short time. And normal dynamic physical simulation cannot meet the teaching demand either because of the limitation of transmission line model and other factors. So PSCAD/EMTDC and MATLAB are used to illustrate the the fault location methods in this paper, which can promote the traveling-wave-based fault-location technology. Meanwhile, the traveling-wave-based fault-location method based on characteristic frequencies is analyzed in this paper.
Traveling-Wave-Based Fault Location in Electrical Distribution Systems With Digital Simulations Tang, Jinrui; Yin, Xianggen; Zhang, Zhe
TELKOMNIKA Telecommunication, Computing, Electronics and Control Vol 12, No 2: June 2014
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Traveling-wave-based fault location in electrical distribution systems is an important safeguard for the distribution network reliability. The effectiveness of the methods is verified directly in power grid in the early stages, while different fault types cant appear in a short time. And normal dynamic physical simulation cannot meet the teaching demand either because of the limitation of transmission line model and other factors. So PSCAD/EMTDC and MATLAB are used to illustrate the the fault location methods in this paper, which can promote the traveling-wave-based fault-location technology. Meanwhile, the traveling-wave-based fault-location method based on characteristic frequencies is analyzed in this paper.