Yunnan Power Company

Kunming, China

Yunnan Power Company

Kunming, China

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Yang Q.,Chongqing University | Ran J.,Chongqing University | Han R.,Chongqing University | Sun S.,Chongqing University | And 2 more authors.
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2016

According to IEEE Guide for Reducing Bird-Related Outages, several types of transmission line faults could be induced by birds. The number of birds increases as human awareness of environmental protection increases. Thus, the probability of suspension insulator string flashover induced by bird streamer would also increase. Analysis of transmission line faults in Yunnan, China, shows that many transmission line faults occurred in the winter bird migration zone, and most of the towers affected are 110 kV transmission line towers. Hence, investigating the flashover process of the 110 kV transmission line suspension insulator strings induced by bird streamer and designing a well bird-preventing installation for 110 kV transmission line suspension insulator strings is necessary. In this study, a simplified, self-designed 110 kV transmission line tower is utilized to experiment on the three types of 110 kV transmission line suspension insulator string with bird simulation excrement. The analysis of withstand test results has revealed the mechanism of flashover caused by bird streamer of the three types of suspension insulator string, and the protection radius R of the three types of insulator string has been presented. The mechanism of flashover and test results have been testified by means of the distributions of electric field and potential calculated by FEM method. Thus, the bird streamer caused flashover could be classified as the shortest air gap breakdown. Hence, it is valuable for designing or selecting a well bird-preventing installation. © 2016 IEEE.


Zhu X.,Northeast Dianli University | Yu B.,Henan Electric Power Company | Zhang W.,Yunnan Power Company
Proceedings 2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011 | Year: 2011

Based on the complex network theory, this paper proposes a weighting parameters based on the voltage and reactance of the transmission lines, and a new method to measure the vulnerability of power grid through the betweenness index. This paper gives a new weight formula and a algorithm to identification of vulnerable lines. The analysis has been carried out on the IEEE5bus system, which confirms the efficacy and practical of the method. © 2011 IEEE.


Qian G.Q.,Yunnan Power Company | Lu Y.,Yunnan Power Company | Wang F.H.,Shanghai JiaoTong University | He M.Z.,Shanghai JiaoTong University
Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference | Year: 2016

Power transformers are always vibrated while working in power system. Those vibration signals are closely related to the mechanical properties of transformer winding. This paper deals with the harmonic response analysis of transformer winding based on finite element method to explore its inherent vibration feature, where a 3-dimensional model of some 10kV transformer winding is built. The frequency response of transformer winding under normal condition and typical fault conditions are analyzed. The modal experiment of transformer winding is designed and made for verification. It is seen that the calculated results of frequency response of transformer winding are agreed well with the measured results. There are four apparent peak in frequency response curve corresponding to the first four order natural frequency of transformer winding. When the winding is loosened or deformed, the peak and the corresponding frequency in frequency response curve are also changed. © 2016 IEEE.


Yan B.,Yunnan Power Company | Qian G.Q.,Yunnan Power Company | Wang F.H.,Shanghai JiaoTong University | Chen S.,Shanghai JiaoTong University
Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference | Year: 2016

This paper presents a new method to recognize the noise characteristics of power transformer. First, frame division and windowing are applied to pre-process the noise signals. Then Mel Frequency Cepstrum Coefficient (MFCC) combined with Principal Component Analysis (PCA) is proposed to calculate the feature vectors of noise signals for high accuracy. Finally, the vector quantization (VQ) models are built to recognize the noise characteristics. The noise signals of some 10kV transformer are measured when the core is loosened in different degree. It is shown that the proposed MFCC is capable of describing the noise features of transformer accurately. The results of noise recognition by VQ are agreed well with the preset condition of core. The obtained results are helpful for the optimum design and mechanical condition assessment of power transformer. © 2016 IEEE.


Wang F.,Shanghai JiaoTong University | Duan R.,Shanghai JiaoTong University | Geng C.,Shanghai JiaoTong University | Qian G.,Yunnan Power Company | Lu Y.,Yunnan Power Company
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2016

To further understand the vibration mechanism of transformer winding, a 3D finite element model of some real transformer was built in the paper. The whole simulation of winding vibration response excited by eletro-dynamic force was made based on the magnetic-mechanical coupling field theory. During the calculation process, the Mooney-Rivlin model was applied to simulate the nonlinear material characteristics of winding block to accurately improve the simulation results. The vibration signals of some 35 kV power transformer were measured. It is shown that the simulated vibration waveforms of transformer winding are matched well with the measured results by the optical vibration sensor which is deployed on the surface of transformer winding. Hence, the effectiveness of the finite element model of transformer winding is verified. In addition, when the winding is loosened, the stiffness of block is increased, as well as the 100 Hz component and its multiple frequency in vibration signals. However, the increments of 100 Hz component and its multiple frequencies in vibration signals are different. The calculated results could provide the important references for the optimized design of transformer winding and the detection of winding deformation by vibration analysis method. © 2016 Chin. Soc. for Elec. Eng.


Meng G.,Wuhan University | Meng G.,State Grid Electric Power Research Institute of China | Wen X.,Wuhan University | Deng W.,State Grid Electric Power Research Institute of China | And 3 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2013

Phase-to-phase switching impulse discharge characteristics play an important role in the design of substation equipment. In order to get the design foundation of 500 kV substations at high altitudes in China, taking into account of 500 kV Jiantang transmission project in Yunnan Province, we practically simulated and tested phase-to-phase switching impulse discharges between flexible buses or grading rings and a typical electrode pair in 500 kV substations. The experiments were performed in 3 areas at different altitude: Wuhan 23 m, Xining 2254 m and Dawu 3742 m, in which phase-to-phase switching impulse discharge curves for gaps of 5~8 m were obtained using the up-and-down method. The influences of voltage distribution coefficients on the gas insulation of phase-to-phase gaps were analyzed, and the experimental results were corrected for the altitudes and then comparatively analyzed. It is concluded that the discharge voltage of air gap decreases sharply with increasing altitude, meanwhile, U50, the 50% switching impulse discharge voltage of phase-to-phase insulation, increases with the voltage distribution coefficient. According to a comparison among several altitude-correction methods, the method in IEC 60071-2-1996 and the m-factor involved altitude-correction method are suggested for phase-to-phase switching impulse's altitude corrections of grading rings and flexible buses in 500 kV substations at high altitudes, respectively.


Meng G.,Wuhan University | Meng G.,State Grid Electric Power Research Institute of China | Wen X.,Wuhan University | Deng W.,State Grid Electric Power Research Institute of China | And 3 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2013

In order to get the design foundation of 500 kV substations at high altitudes in China, we employed the up-and-down method to investigate the switching impulse and lightning impulse discharge characteristics of typical simulation frameworks of 500 kV substation at three altitudes (Wuhan 23 m, Xining 2 254 m, Dawu 3742 m) by combining with 500 kV Jiangtang transmission project in Yunnan Province. Switching impulse and lightning impulse discharge curves were obtained with phase-ground gaps of 3~6 m, and several altitude correction methods were used to calibrate and analyze the results so as to give the appropriate correction method for Jiangtang transmission project. The experiments show that the 50% lightning impulse voltages and 50% switching impulse voltages decline with increasing altitudes, but the trend and level of changes have notable differences. Meanwhile, the saturation 50% switching impulse voltage curve is more significant with increasing gaps. According to comparison among altitude-correcting methods, it is concluded that IEC 60071-2: 1996 is suited for correcting lightning impulses of 500 kV substations, and the correction method containing m factor is suited for correcting switching impulses in phase-ground gaps.


Xiong X.-F.,Chongqing University of Technology | Gong X.-F.,Chongqing University of Technology | Wang Y.-X.,Yunnan Power Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2013

Meteorological factors will cause the transmission line fault and affect the power system reliability prominently. The original reliability parameter model which considered the meteorological factors is improved, and it is pointed out that transmission lines in different geography have different average failure rate, and their corresponding three kinds of weather and the percentage of number of failures under the three kinds of weather also show great difference. Connection number is used to deal with the uncertainty of reliability original data and weather conditions. RBTS is evaluated with state enumeration method, and the reliability indices in form of connection number are obtained. The result shows that the uneven geography and meteorology will affect the reliability evaluation of the transmission system greatly, and the reliability indices in form of connection number also give the uncertain part, which proves the reliability of the proposed method.


Wu W.,Yunnan Power Company | Gong Y.,Yunnan Power Company | Yang K.,Yunnan Power Company
2013 8th International ICST Conference on Communications and Networking in China, CHINACOM 2013 - Proceedings | Year: 2013

With the development of power distribution system, it is necessary to provide a new communication infrastructure to support broad band and wireless access network in smart grids. In this paper, we propose an experimental access layer platform for power distribution network based on LTE technology. Some typical services such as concentrated meter reading, remote video surveillance, and system operation status monitoring are tested in the experimental system, which is deployed in Mengzi city, Yunnan province. The experimental results show that the proposed experimental system is robust and can satisfy the basic QoS requirements of the typical services in power distribution system. © 2013 IEEE.


Zhou D.-J.,Zhejiang University | Yang L.,Zhejiang University | Guo Y.-M.,Yunnan Power Company | Wang M.-W.,Taizhou Electrical Power Supply Bureau
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

Considering the characteristics of hydrothermal coordination scheduling, this paper presents a hydrothermal coordination scheduling model with cascade reservoirs in which cascade reservoirs' time coupling and water coupling characteristics and vibration intervals of hydro units are considered. An antibody segment is used to represent unit states. Considering the practical engineering characteristic, the immune algorithm is improved in two aspects. Firstly, pseudo integer variables are used to disperse the hydro units into discontinuous steady output ranges. The stable intervals are memorized by units re-encoding. Antibody coding is not lengthened while algorithm efficiency is improved. Secondly, a self-adaptive mutation for antibody segment is adopted due to the characteristic that different units share different loads (base load, peak load and middle load). At the same time, a self-adaptive mutation method considering antibody affinity is adopted to reduce the blindness of algorithm and improve the optimization efficiency. Finally, a revised IEEE 118-bus system is used to analyze the validity and rationality of the proposed method.

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