Shaohua You
North China Electric Power University
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Featured researches published by Shaohua You.
IEEE Transactions on Power Delivery | 2012
Fangcheng Lu; Shaohua You; Yunpeng Liu; Qifa Wan; Zhi-Bin Zhao
Corona loss generated from conductors is one of the important design factors of extremely high-voltage ultra-high voltage (EHV/UHV) ac transmission lines. The charge simulation method was adopted to calculate conductor corona loss in the corona cage. Every corona cage wall is equivalent to the ground plane and, therefore, the calculation model is more complicated than the power-line model above the ground surface. Two corona cages-UHV corona cage and small corona cage-were adopted in the tests. The cages are both square sections. Single conductors and bundle conductors were tested in the corona cages to verify the corona cage calculation model. And the same type of conductor was tested in the small corona cage and in the UHV corona cage to check the measuring system and the simulation program of corona loss further. Since the artificial rain rates were from 12 to 20 mm/h, corona losses were measured and calculated. The results indicate that the fundamental frequency component is the most main component of corona loss. The corona cage corona-loss calculation model is appropriate. And for single conductor LGJ-500/35 and bundle conductors, 8 LGJ-500/35, under heavy rain conditions, with the rain rate being from 12 to 20 mm/h, the roughness coefficient range is from 0.4 to 0.5 approximately.
IEEE Transactions on Power Delivery | 2012
Yunpeng Liu; Shaohua You; Fangcheng Lu; Qifa Wan; Xingming Bian; Liming Wang
In order to research an altitudes effect on corona onset voltage of bundle conductors in a corona cage, a calculation model was established, and corresponding test proceeded. The charge simulation method was adopted to calculate space electric-ήeld strength. According to self-sustained discharge criterion in a severe nonuniform electric ήeld, and variation of altitude, the corona onset voltage calculation model of bundle conductors in a corona cage was established. The corona onset voltages of bundle conductors, which were used in the 500-kV extremely high voltage transmission line, were tested at different altitude locations, as Wuhan 19 m, Xining 2261 m, Golmud 2829 m, and Nachitai 3800 m. Corona onset voltages of 4 × LGJ - 0400/5 and 4 × LGJ - 300/25 were obtained. The corona onset voltage curves at different altitude, bundle spacing, and bundle numbers were obtained. The analysis shows that the model can be used to provide accurate values of corona onset voltage for bundled stranded conductors in the corona cage at various altitudes. With bundle spacing from 350 to 500 mm, the corona onset voltage decreases as bundle spacing increases, and the onset voltage increases as the bundle number increases. As altitude increases every 1000 m, the corona onset voltage of bundle conductors decreases by about 8.5%.
international conference on electrical and control engineering | 2011
Fangcheng Lu; Shaohua You; Yunpeng Liu; Lei Zhu
Corona current is one of important corona characteristic research contents. In order to analyze conductor corona current harmonic wave characteristic, a corona current measurement system is developed. The synchronous collect of the voltage and current signal is realized by the GPS technology. The corona current signal is transmitted to the lower computer through the wireless network. And the current signal collected in this way is safe and reliable. The measurement system can be used to measure the wide frequency band corona current. Advanced Hanning windowed interpolation FFT algorithm was adopted, and conductor corona current harmonic wave was analyzed. Corona current harmonic characteristics before and after corona onset were compared. Research results show that, after corona onset, corona current odd harmonic increases in evidence, and even-order harmonic increase less relatively. Triple-frequency harmonics and quintuple harmonics increase obviously very much, and conductor corona current harmonic analysis can be used to research conductor corona characteristic.
ieee international conference on properties and applications of dielectric materials | 2009
Yunpeng Liu; Shaohua You; Qifa Wan; Fangcheng Lu; Weijiang Chen; Yong Chen
Transmission line corona loss research is one of the critical technologies of 1000kV UHV transmission and transformation engineering. Transmission line corona loss relates with many factors of climate, and rainfall rate effects corona loss distinctly very much. By means of UHV AC single circuit test line corona loss monitoring and UHV corona cage conductor corona loss measurement, this paper researched the effect of rainfall rates to UHV AC single circuit transmission lines corona loss. This paper applied corona loss monitoring system to monitor corona loss of UHV single circuit test line, and obtained corona loss monitoring data in light rain, moderate rain, and heavy rain conditions. Analyze corona loss test results. Corona loss value in light rain, moderate rain, and heavy rain conditions are obtained. The results show that, rain has an obvious influence on corona loss of the line, at the beginning of raining, corona loss increases quickly, after rain, corona loss decreases with drying of the conductor. Decay time is related with surface field strength, wind speed, air humidity, temperature and other factors. When rainfall rate is low, corona loss increases fast with the increase of the rainfall rate. With the increase of the rainfall rate, corona loss grows slowly. When rainfall rate increases to some level, corona loss stop growing.
ieee international conference on properties and applications of dielectric materials | 2009
Yunpeng Liu; Tao Yu; Song Gao; Jie Lu; Shaohua You; Daochun Huang
Combining with optical fiber transmission technology and digital signal processing technique, a leakage current monitoring system suitable for iced insulators based on fiber optic transmission has been developed by making use of multiple channel and high precision data synchronous collecting cards and virtual instrument technology software programmed. The designs of the leakage current sensor and protective device are introduced in detail. The design thinking and functions of the software are described. This leakage current monitoring system is validated by the flashover tests of artificial iced insulator string in the small artificial ice testing laboratory of Wuhan High Voltage Research Institute of SGCC.
international conference on electrical and control engineering | 2011
Shaohua You; Fangcheng Lu; Yunpeng Liu; Wenfang Zeng; Xiangyuan Wu
Corona cage was an important research method to research corona effect. As design corona cage, the distance form cage wall to conductor, critical distance of AC charge, and corona cage length, and these questions should be resolved. Corona onset voltage, breakdown voltages were important coefficients to research conductor corona characteristics, and this was significant for transmission line design. To a certain diameter conductor, the diameter of corona cage should be small enough to make the conductor corona onset at a low voltage. Simultaneously, the gap between cage wall and conductor should be lager enough, so as to make breakdown voltage 50% higher than corona onset voltage. The critical distance of AC charge was calculated, and the length of corona cage was selected. The cross-section side width of the corona cage was 1.8m × 1.8m., and the measurement length of the cage was 3m, both of the protection length were 0.5m respectively. As in test, conductors were placed in at the center of the cage, and corona loss measurement system was adopted to measure conductors corona loss. Corona loss of conductor LGJ-630/45, LGJ-400/35, LGJ-300/40 were measured, and an excellent test effect was obtained.
Archive | 2011
Yunpeng Liu; Zongjun Huang; Fangcheng Lu; Qifa Wan; Xiongjie Xie; Shaohua You; Lei Zhu
Archive | 2010
Yong Chen; Zongjun Huang; Runqiu Li; Yunpeng Liu; Qiang Sun; Qifa Wan; Lin Xing; Shaohua You; Anming Zhu
Archive | 2008
Yunpeng Liu; Qifa Wan; Weijiang Chen; Shaohua You; Yong Chen; Fangcheng Lu; Leijian Ren
Archive | 2009
Yunpeng Liu; Qifa Wan; Weijiang Chen; Shaohua You; Yong Chen; Fangcheng Lu; Leijian Ren