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Xie H.-F.,China Southern Power Grid Maintenance and Test Center | Wang G.-J.,Foshan Power Supply Bureau | Zhang Y.,South China University of Technology | Lin L.-X.,South China University of Technology
Dianwang Jishu/Power System Technology | Year: 2010

Emergency DC Power Support (EDCPS) function can quickly modulate available DC power when heavy fault occurs in parallel AC lines or other HVDC systems, and finally enhances transient stability with short-time DC overload capacity. Therefore, how to implement online EDCPS prediction by wide area measurement system (WAMS) signals is of great significance and deserves to be researched. An online EDCPS prediction model based on WAMS signals is introduced, and a newly structured orthogonal wavelet neural network based on multi-resolution analysis is constructed and applied to the ECDPS prediction of HVDC power transmission project from Yunnan to Guangdong. Adopting orthogonal scaling function as activation function, this multi-resolution analysis orthogonal wavelet neural network (MAOWNN) can converge fast and ensure the uniqueness of approximating function expression. Simulation results show that based on dimension-reduced principal components the MAOWNN can accurately give the controlled quantity of EDCPS. Source

Peng D.-H.,China Southern Power Grid Maintenance and Test Center | Zhang N.,China Southern Power Grid Maintenance and Test Center | Zhou Q.-Y.,XJ Electrical Co. | Huang J.-H.,XJ Electrical Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2014

DC protection hardware platform of Guizhou-Guangdong DC I and DC II is based on SIMADYN D system. In order to improve the efficiency of the DC protection maintenance and regular inspect, this paper develops a regular inspection system. The system meets code requirements, is easy to operate, and also has friendly interface and other characteristics. It's running in the mainstream Window operating system, which can replace debugging tools IBS and achieve the function of DC protection systems digital, analog input channel information display and monitoring, as well as digital and analog outputs issuing, etc. Source

Yang G.Y.,China Southern Power Grid Maintenance and Test Center | Li X.Y.,University of Sichuan | Hu Y.Y.,University of Sichuan | Li K.,University of Sichuan
Advanced Materials Research | Year: 2013

The thyristor has been widely used in many fields since it has been invented, and has promoted the development of the DC transmission technology rapidly. The increasing temperature of its junction may cause serious hazards. Because of this, a variety of methods that can obtain the junction temperature has been summarized in this paper, such as the indirect measurement method, the direct measurement method, the equivalent thermal impedance network method and the numerical calculation method, etc. Summaries have been made in different occasions which these methods were applied. It also compared the advantages and disadvantages of each method and pointed out the developing trends and researching directions in the future. © (2013) Trans Tech Publications, Switzerland. Source

Huang Y.,China Southern Power Grid Maintenance and Test Center | Zhou Q.,China Southern Power Grid Maintenance and Test Center | Dai G.,XJ Electrical Co.
Gaoya Dianqi/High Voltage Apparatus | Year: 2014

Considering the multiple switching of the metallic return transfer breaker (MRTB) after earth/metallic loop transfer in Chu-Sui UHVDC system, the switching process of MRTB is analyzed in detail in terms of 82MRTB protection, MRTB switching command, the sequence control logic of earth/metallic loop transfer, and the lightning arrester monitoring, etc. Two modified schemes are proposed with regard to priority of switching and modification of sequence control logic. Comparative analysis is performed to determine the final scheme, in which the MRTB switch-off command is exerted on MRTB switch itself without any logic or broadening processing. Simulation results obtained on the RTDS SIMIT simulation platform verify the feasibility and effectiveness of the modified scheme. Source

Wang H.-J.,China Southern Power Grid Maintenance and Test Center | Huang Y.-L.,China Southern Power Grid Maintenance and Test Center | Zhou Q.,China Southern Power Grid Maintenance and Test Center
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2014

From the principle of extinction angle control used in HVDC, the advantage and shortage of extinction angle control based on actual measuring and predictive calculation are contrasted. And the response strategies of commutation failure based on the Siemens and ABB technology are discussed from control and protection system. The response of commutation failure prediction control function (CFPREV) under AC voltage falling and distortion fault are focused. The results of simulation show that, when AC voltage falls seriously, the CFPREV cannot prevent commutation failure, but the CFPREV is in the favour of the restoration of DC system after commutation failure; when the electrical relation between DC and AC system is strong or the distortion degree of AC voltage is low, the CFPREV function has obvious effect on preventing commutation failure. ©, 2014, Power System Protection and Control Press. All right reserved. Source

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