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Wu H.,University of Sichuan | Yang P.,University of Sichuan | Chang Z.,Sichuan Electric Power Research Institute | Cai L.,Sichuan Bazhong Electrical Power Bureau
Proceedings of the 2012 4th International Symposium on Information Science and Engineering, ISISE 2012 | Year: 2012

Fault phase selection is studied in this paper based on the wavelet power spectrum entropy and LIBSVM for transmission line. First, MATLAB is used to simulate five fault types and obtain a variety of fault voltage waveforms. Second, the simulation waveform is transformed to extract the energy spectrum entropy which is pretreatment to greatly reduce the number of data dimensions and effectively optimize the input data of LIBSVM. Finally, LIBSVM is used to select fault phase, experimental results show that the method is very effective. © 2012 IEEE. Source


Wu H.,University of Sichuan | Guo H.,University of Sichuan | Cai L.,Sichuan Bazhong Electrical Power Bureau
Gaoya Dianqi/High Voltage Apparatus | Year: 2013

Fault-phase selection is not only an important link on corrective actions of high-voltage transmission lines protection, but also an important prerequisite for accurate fault location. The traditional fault phase selection method is only applicable to simple fault, low sensitivity, and easily affected by system operation mode, fault grounding resistance etc. On the basis of the analysis for fault component of each phase current, this paper gives a definition of fault component energy by the concept of signal energy and presents a new type of fault phase identification method based on fault component energy coefficient. This method directly uses the fault current to extract fault components and calculate the signal energy of fault component for 2 cycles after fault inception, and the ratio coefficient that fault component energy of each phase current accounts the total energy can be gotten. Then probabilistic neural network of fault phase selection may be established to select fault phase by fault phase identification feature vector. Simulation results show that the method which has high capability is not affected by the initial phase angle of fault, the fault position and transition resistance. It can determine fault phases accurately. The theoretical analysis and simulation results verify the validity of the method. Source


Huang Z.,Southwest Jiaotong University | Jiang T.,Sichuan Bazhong Electrical Power Bureau | Zhang W.,Sichuan Bazhong Electrical Power Bureau | Wu S.,Sichuan Bazhong Electrical Power Bureau | And 5 more authors.
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

The design of traveling-wave-based fault locating card is proposed for high voltage lines, which is added on the microcomputer based line protection or fault recorder. With the concept of highly independent operation, it has own functional circuits: CPU, high speed data acquisition, high precision clock, digital inputs, digital outputs, communication interfaces, voltage converter, etc., and applies an embedded operating system to coordinately dispatch various functional software tasks. A type of microcomputer based line protection is slightly reconstructed and a matched card is developed. The card fetches DC power from the mother board of the protection and communicates with the HMI unit via the mother board. Its application realizes the integration of fault locating and line protection or fault recording. Source


Huang Z.,Southwest Jiaotong University | Jiang T.,Sichuan Bazhong Electrical Power Bureau | Zhang W.,Sichuan Bazhong Electrical Power Bureau | Wu C.,Sichuan Bazhong Electrical Power Bureau | And 3 more authors.
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

The basic principle of adaptive instantaneous current protection for distribution line is analyzed, based on which a protection and supervisory control device with adaptive instantaneous current protection function is developed for distribution lines. It mainly includes the CPU, transformer card, trip relay card, power card and human machine interface module. The CPU card integrates MCU, DSP, FPGA, SRAM and Flash RAM, as well as the data acquisition circuit, digital input/output circuit and communication interface circuit. Its software aggregates the functions of adaptive instantaneous current protection, traditional three-stage current protection, three-phase reclose, low frequency shedder, event alarm, SCAD A and fault recorder. Test shows that, the developed device has reliable functions and flexible configuration, and its protective performance is automatically adjusted to an optimal state according to the system operating mode, fault type and load conditions. Source


Huang Z.,Southwest Jiaotong University | Jiang T.,Sichuan Bazhong Electrical Power Bureau | Zhang W.,Sichuan Bazhong Electrical Power Bureau | Wu S.,Sichuan Bazhong Electrical Power Bureau | And 2 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2010

A fault location method based on double-ended travelling wave principle is presented for the 110 kV and above high-voltage overhead lines combined with underground power cables. Firstly, the fault section is determined by comparing the time difference between the arrival times of the fault induced initial travelling wave detected at two ends of the combined line with a setting value. Then, according to the different fault section, the corresponding fault location algorithms for combined lines based on double-ended travelling wave principle are derived. In order to test the validity of the presented travelling wave based fault location method for combined lines, the fault location algorithms are embedded into the ordinary double-ended travelling wave based fault locators, and a simulation test for the changed fault locators are completed using the special verification instrument for travelling wave based fault locators. The test results show that the presented fault location method for combined lines based on travelling waves is feasible and practical. © 2010 State Grid Electric Power Research Institute Press. Source

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