Lu J.,CAS Chengdu Institute of Mountain Hazards and Environment |
Liao X.,SICHUAN Electrical Power Design and Consulting Co.
Advanced Materials Research | Year: 2012
According to an practical construction of an subway station, the foundation excavation three dimensional model was built by FLAC3D from the need of practical engineering. The status and variation characteristics of the displacement field, deformation field and plastic failure zone were obtained. Guiding significance was provided by the simulation. © (2012) Trans Tech Publications.
Zhou L.,Sichuan Electrical Power Design and Consulting Co. |
Liu C.,Sichuan Electrical Power Design and Consulting Co. |
Wang Y.,Sichuan University |
Yang J.,Yunnan Power Grid Co.
MATEC Web of Conferences | Year: 2016
Lightning has become a big threat to the safe operation of the main transmission line. Reasonable and accurate calculation of shielding failure rate plays important role in transmission line and tower design. This paper proposes a hybrid approach to calculate the shielding failure-caused trip-out rate, based on the typical electrogeometric model and the regulation method. The case study prove the validity and correctness of this approach, by comparing with the actual operation shielding failure rate. © 2016 The Authors, published by EDP Sciences.
Huang T.,Nanjing Southeast University |
Gong W.-M.,Nanjing Southeast University |
Li H.,Sichuan Electrical Power Design and Consulting Co. |
Dai G.-L.,Nanjing Southeast University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2011
The base post-grouting is used to improve the base resistance of piles, and the mechanism of base post-grouting in super-long piles needs to be a deep studied. In order to study the bearing capacity, static load tests are carried out on super-long bored piles employed in great bridges. The differences of the bearing capacity of super-long piled before and after base grouting are analyzed. Based on the test results, it is found that the bearing capacity of piles is increased by over 10 percent after base grouting. The frictional resistance at the lower part of piles increases significantly. As the load increases, the role of base grouting is more obvious. A comparative study between the field measured and calculated increments of the bearing capacity is made. The results indicate that the calculated increments of domestic standards are smaller than the field measured increments, and some calculated increments are over-conservative.
Shao L.,Huanghuai University |
Zhou X.,Sichuan Electrical Power Design and Consulting Co. |
Zeng H.,Hubei University
Open Civil Engineering Journal | Year: 2016
Soil pressure calculation method for Trenchless pipe based on the Terzaghi Soil Arching Theory have been defined in Chinese national standard GB50332-2002, North America standard ASTM F1962-09 and European standard BS EN 1594-2009. At present, the calculation results from all of the three standards have shown discrepancies with the measured soil pressure. There is little research on the issue of discrepancies in each standard based on the same Terzaghi soil arching theory. The comparison has been made to investigate the differences among all the three standards. The conclusions can be made that the calculation in both GB50332 and ASTM F1962 ignores the cohesion and compressibility of the soil, using the same method to calculate sand soil and clay soil, and does not fully consider the effect of the internal friction angle of soils, which lead to a small impact of the soil properties on the arching factor. The BS EN 1594 standard considers the cohesion strength of soils and uses two different methods for pressure of sand soil and clay soil, respectively; The comparisons show that the cohesion strength has a significant impact on soil pressure, and that the former two standards showed a higher soil pressure than BS EN 1594 since both of them ignored the cohesion strength of soils. © Shao et al.
Fan R.-Q.,Sichuan Electric Power Corporation |
Cao M.-G.,China Electric Power Research Institute |
Zhuo Y.,Sichuan Electrical Power Design and Consulting Co. |
Lu Z.-C.,China Electric Power Research Institute |
Zhang X.-S.,China Electric Power Research Institute
Gaoya Dianqi/High Voltage Apparatus | Year: 2012
High voltage circuit breakers are one of the key electrical equipment in power systems which aseismic capacity is weak. Firstly, survey and analysis on earthquake disaster of circuit breakers in 5.12 Wenchuan earthquake are carried on. In addition, acceleration and stress response of SF 6 circuit breaker, subjected by varied earthquake wave in shaking table testing. As is shown that damage of circuit breakers is severe in the above VII level (earthquake intensity) region. Generally, there are four types of typical damage. It is essential that some effective aseismic measures are adopted to improving aseismic capacity for circuit breakers. There are two methods to enhance circuit breaker aseismic capacity, one is conventional aseismic technology, another is isolation and damping technology which have obvious advantages for the distinct principle and notable efficiency. Finally, considering to structural feature, the three suitable schemes on isolation and damping technology of circuit breaker are put forward. This research has some certain reference to aseismic design and reinforcement of circuit breaker electrical equipment.
Zhou L.,Chongqing University |
Chao Y.,Chongqing University |
Liao B.,Sichuan Electrical Power Design and Consulting CO. |
Ren W.,Chongqing University |
And 2 more authors.
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2014
The grid synchronization signal detection is a key to control the converter to be connected to the grid for new energy. For the weak points of the phase-lock loop, a grid synchronization signal real-time detecting method based on reference frequency is proposed in the paper. Only to detect the single-phase grid-voltage operated with sine and cosine signals of reference frequency, the grid synchronization signal can be detected in case of the three phase grid distorted and unbalanced. For the big phase deviation of the synchronization signal caused by frequency fluctuation, to improve the low-pass filtering link a negative feedback and proportional control is introduced, and the phase deviation can be corrected in satisfied index. The theoretical and experimental study results verify that the method is correct and effective. © 2014 Chin. Soc. for Elec. Eng.
Yan W.,Chongqing University |
Wang F.,Chongqing University |
Tang W.-Z.,Chongqing Electric Power Research Institute |
Zhao X.,Chongqing University |
And 2 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2013
A novel partitioning method is proposed based on power sources clustering and short-circuit impedance distance, which is characterized by Mvar source nodes partitioning and load nodes mapping. The electrical distance between two Mvar source nodes is defined based on the sensitivity of voltage to reactive power injection, and the agglomerate hierarchical clustering algorithm is applied to partition the Mvar source nodes. Then the short-circuit impedance distance between multiple Mvar source nodes and a single load node is defined, and the mapping between load nodes and Mvar sources partitions is realized by minimizing the short-circuit impedance distances. With the presented method, not only the Mvar source nodes within a short electrical distance from each other, but also the load nodes and the multiple Mvar source nodes having a strong control relation can be clustered into the same partition. The other advantage with the method is that the partition is independent of the power flow state. Simulation results on IEEE39-bus system and the real Chongqing grid data demonstrate the effectiveness of the presented method.
Shu L.,Chongqing University |
Yang Z.,Chongqing University |
Jiang X.,Chongqing University |
Hu Q.,Chongqing University |
And 2 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2014
It is important to reveal the effect of terrestrial solar ultraviolet radiation (TSUVR) on the discharge performance of external insulation for the design and operation of power system in regions where have strong TSUVR. Consequently, we use an artificial UV lamp to imitate TSUVR in experiments to research this effect on positive DC discharge. It is found that TSUVR has no obvious effect on breakdown voltage and corona of air-gap positive DC discharge. That is because the wavelength of TSUVR is in the range of 290~400 nm, and its intensity is less than 200 W/m2, and air, Cu, and Fe can not be photoionized under TSUVR. There is no obvious effect of TSUVR on arc propagation due to energy. Although a part of the photons in TSUVR has higher energy than the work function of Al, Al could be easily oxidized, and the oxide film (Al2O3) prevents Al from being ionized by TSUVR. Therefore, TSUVR has no obvious effect on positive DC discharge performance of air gap. This research will support the design of external insulation in the regions with strong TSUVR.
Hui X.,Si Chuan Electrical Power Design and Consulting CO. |
Ying C.,University of Sichuan
Key Engineering Materials | Year: 2016
High-water material is a kind of new inorganic nonmetal material which mainly used in coal mine goaf filling. In order to simulate the real stress conditions of this material in goaf filling, the creep tests of high-water material in real pressure water environment were conducted and the creep laws were also researched. The results showed that water environment was conductive to maintaining and developing the strength of high-water material, and pressure water environment can improve the carrying capacity and long-term strength of high-water material. The deformation of steady creep period decreased while water pressure increased. And strain increasing caused by axial compression was less than strain increasing caused by water pressure. The time needed from starting to steady creep period was longer when water pressure was bigger. © 2016 Trans Tech Publications, Switzerland.
Li G.-H.,Sichuan Electrical Power Design and Consulting Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010
According to the approach ability of artificial neural network, a novel transformer protection based on the artificial neural network model is proposed. Adopting artificial neural network to approach the electromagnetic relation of transformer, building artificial neural network model to substitute for transformer physical model, identifying internal parameters on line, artificial neural network model based transformer protection is realized after parameter identification. EMTP simulation results demonstrate that the proposed method can recognize internal faults within a half cycle of their occurrence, with apparent fault features and less threshold value. It can discriminate low-level internal faults, without reference to the magnetizing inrush.