Nanchang, China
Nanchang, China

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Wang S.-H.,Shijiazhuang University | Cai Q.-L.,Maintenance Company | Xu J.-Y.,Shijiazhuang University | Chang Y.-J.,Shijiazhuang University | Xue Q.,Shijiazhuang University
Tiedao Xuebao/Journal of the China Railway Society | Year: 2013

To deal with occurring of resonance over-voltages in the traction power supply system of high-speed railways, by analyzing the characteristics of harmonics and comprehensively considering the characteristics of distribution parameters and skin-effect of lines, the method for calculating the parameters of the traction network (a circuit consisting of contenary, feeding lines, rail-ground loops, loop conducting wires and feeding lines between traction substations and contenary) was studied and the equivalent model of the traction power supply system was built to calculate the line parameters of the traction power supply system. With the modal analysis method, the coupling relationship between the traction power network and electric locomotive was decoupled, the vehicle-network coupling based data such as the numbers of harmonic resonances, voltage waveforms and scope of influence and the mechanism of causing resonance over-voltages were determined. With software EMTP-ATP, the simulated vehicle-network coupling model based on EMU CRH2 and AT power supply mode was set up to acquire a good knowledge of the voltage situation of the traction power network in the coupling state. By comparison the simulation results are proved in agreement with the measured data, which verifies the correctness of the simulation model.

Xu J.,Changchun University of Science and Technology | Zhang L.,Changchun University of Science and Technology | Jin J.,Maintenance Company | Wang C.,Liaoning Electrical Power Company Ltd | Zeng Q.,Changchun University of Science and Technology
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012

In order to achieve automatic inspection of 500 kV overhead transmission line, air-borne optoelectronic stabilized pod system for power line inspection applied in cold and high latitude area was designed and manufactured. According to the power line inspection features and tasks of domestic cold area, main technical parameters of the system were determined. According to target minimum resolution, optical imaging system was designed. Active gyro stable technology, passive mechanical damping and electronic image stabilization technology were used to ensure the high stabilization accuracy of the system. Three closed loop structure was used to raise the control bandwidth of the system. Low temperature resistance design was adopted to ensure working performance of the system at low temperature. The results of system stabilization accuracy test and overhead transmission line inspection experiment in cold area show that the stabilization accuracy of air-borne optoelectronic stabilized pod system is superior to 30 μrad. Micro parts such as pins and R/M pins of target object can be clearly identified from the designed instrument within 80 m apart. Its 80 m apart minimum target resolution is superior to 2 mm. This system meets the power line inspection requirements in domestic cold area in winter. It has apparent advantages when used in high latitude and low temperature (-40°C). The validity and rationality of air-borne optoelectronic stabilized pod system in cold area have been verified through tests and experiment. © 2012 Chinese Society for Electrical Engineering.

Liu Y.,Tianjin University | Du B.,Tianjin University | Lu Y.,Beijing Electrical Power Research Institute | Yin Z.,Maintenance Company
Gaodianya Jishu/High Voltage Engineering | Year: 2014

In order to investigate the influence of disastrous fog conditions on the reliability of insulators, taking silicon rubber insulators (SRIs) as the specimens, we analyzed the adsorption and condensation of water droplets and how they affected the flashover voltage of SRIs with different contaminations and different wet conditions, by using a visible experimental system and artificial atmospheric experimental devices. By establishing the relationship among salt-fog contamination degree, relative humidity, adsorption and condensation on SRI surface, and droplet distribution characteristics (including area, size, and box dimension), we obtained the patterns of how these characteristic parameters influence the flashover voltage of SRI. It is shown that, with increasing relative humidity and contamination level, the numbers of both medium-sized (1 mm≤max diameter Dmax<2 mm) and big-sized (Dmax≥2 mm) droplets increase obviously, the number of small-sized (Dmax<1 mm) droplets decreases slightly, and the amount of droplets in total increases. The increase of droplet distribution's box dimension illustrates that the distribution gets more dispersed and more complex. Though the flashover voltage of insulator is not directly reflected by the amount variation of adsorbed droplets on insulator surface, it decreases with the increase in box dimension of droplet distribution.

Wang X.,Jiangxi Electrical Power Corporation | He P.,Maintenance Company | Liu Y.,Jiangxi Electric Power Research Institute | Yan N.,Jiangxi Electric Power Research Institute
Gaoya Dianqi/High Voltage Apparatus | Year: 2014

An accident of a 500 kV hybrid gas insulated switchgear (HGIS) in a 500 kV substation is analyzed. Disassembly inspection of the HGIS reveals that the basin insulator for VT chamber has been burnt into pieces due to discharge, and the poor quality of the basin insulator caused this accident. Subsequently, this malfunctioned equipment is replaced, and chemical and electrical tests are conducted for the basin insulators in same batch. In addition, some countermeasures are suggested.

Xiong Q.,Hunan University | Luo A.,Hunan University | Wang X.,Maintenance Company | Li X.,Hunan University | And 2 more authors.
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2014

There exists 100 Hz ripple in the DC side capacitor voltage of the cascaded static var generator (SVG), and the filter circuit is often used in the detection of DC side voltage. Mainly the effect of the filter circuit on the stability of the DC side voltage is studied. The DC side voltage closed-loop control model containing the filter circuit is established according to the principle of the energy balance. An analysis of the stability of the control model shows that the necessary condition for the robust stability of the system is to obtain the regulator integral time constant greater than the filter time constant. A 13-level SVG experimental prototype is built. Experimental results under 220 V and 3 000 V voltage respectively have verified the correctness of the stability analysis. © 2014 State Grid Electric Power Research Institute Press.

Wang Z.,Changchun University of Science and Technology | Yu Z.,Changchun University of Science and Technology | Xu J.,Changchun University of Science and Technology | Wang X.,Changchun University of Science and Technology | And 3 more authors.
2015 IEEE International Conference on Mechatronics and Automation, ICMA 2015 | Year: 2015

In order to meet the demand of automation in high voltage transmission lines inspection and improve its precision, a remote distance inspection system is developed which is based on laser ranging and image processing technology. This system is used to detect the secure distance between transmission lines and object below it and scale of objects. Remote distance inspection system includes upper position computer and lower position machine. The lower position machine consisted of high revolution camera, two laser rangers, digital compass and GPS, these devices sent images, distance, attitude and location information to upper position computer. Measurement formulas derived from imaging principle. Upper position computer completes image process, measurement and other information management automatically. System structure is designed with light weight feature and total mass is 4kg, it is available on vehicle and unmanned aerial vehicle. System control software is developed with C++ language, inspection image and datum are recorded for the automated management. The system have been tested over a distance of 52m, 89m and 132m from objects, results show that the percent relative error is +1.9%, -2.2%, +2.9%, respectively. The high accuracy performance of this system is proved. © 2015 IEEE.

Zhang B.,Sichuan Electric Power Corporation | Wang Y.,University of Sichuan | Li X.,University of Sichuan | Zhang G.,Maintenance Company | And 2 more authors.
Gaoya Dianqi/High Voltage Apparatus | Year: 2015

Aiming at the problem that a converter transformer is complex in structure and it is difficult to evaluate its condition accurately, a condition evaluation method based on DHGF algorithm is proposed for the converter transformer. The evaluation index sets and the corresponding weights are established, and the whitening weighting function, the weight matrix and the evaluation matrix are provided to construct a complete mathematical model. The condition of a real converter transformer is analyzed by using DHGF method, thus the condition level and the exact score are obtained. The results can reflect the real condition of the converter transformer, and can be used to support the next decision making of maintenance. ©, 2015, Xi'an High Voltage Apparatus Research Institute. All right reserved.

Gong J.,Northeast Dianli University | Ren D.X.,Northeast Dianli University | Zhou C.,Qinghai Hainan Electrical Power Supply Company | Ma G.Q.,Maintenance Company
Applied Mechanics and Materials | Year: 2013

Take advantages of concrete to improve the stiffness of fiber reinforced composite material(GFRP), reference to the existing dimensions of concrete-filled steel tube pole, applicate GFRP-concrete structure in 35 kV transmission line. Change the various parameters of the poles in ANSYS, compare the maximum deformations and the maximum stresses of GFRP tube-concrete pole and concrete-filled steel tube pole. Results show that different parameters have different impacts on the mechanical properties of the poles, suitable parameters of GFRP tube-concrete pole were got and the technical specifications of the application of GFRP in various voltage levels should be perfected. © (2013) Trans Tech Publications, Switzerland.

Jia Y.Z.,Northeast Dianli University | Wang M.Q.,Northeast Dianli University | Zhang J.,Maintenance Company | Liu J.,Jilin Baicheng Electrical Power Supply Company
Applied Mechanics and Materials | Year: 2013

Using the software of ABAQUS,for the Geological conditions that the upper part is the clay and the Lower part is the rock.The model of digging plus rock bolt Complex environmentally undisturbed soil foundation combined with soil.Which analysis by the numerical simulation.Refer to the test compound type foundation's Dimensions,get a three-dimensional finite element model.Applying the same concentration and test loads.Get the oad-displacement curve obtained by calculation.Measured values with the experimental results was very close to,This proved the feasibility of numerical simulation methods. © (2014) Trans Tech Publications, Switzerland.

Hu J.,China Electric Power Research Institute | Guo R.,Maintenance Company | Pei C.,Taiyuan Electrical Power Company of SGCC | Min X.,China Electric Power Research Institute | And 2 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2013

Taking the characteristics of ultra-high voltage(UHV) transmission line into consideration, we established conductor-insulator strings coupled finite element models of single-span and three-span lines, then calculated and compared galloping of UHV transmission lines with the models. The results show that a relatively large difference exists between the calculation results of the single-span and three-span models (the average difference rate is 10.9%), when the left and right spans have the same height and no matter the lines are triangularly-arranged or horizontally-arranged; however, when the left and right spans have a height difference more than 50 meters, the calculation results of the single-span model well agree with those of the three-span model (the average difference rate is 4.9%). The fixed constraint of single-span model produces a strong constraint force, meanwhile, the large height difference in three-span model enhances the constraint of middle span, leading to calculative conditions close to the fixed constraint of single-span model, so there is good agreement between the results of the two models. It is concluded that when a large height difference exists between left and right spans, single-span model can replace three-span model to calculate and emulate galloping, so the time cost of computing can be reduced without affecting the deviation the calculation results.

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