Xu P.,Maintenance Company of Anhui Electrical Power Corporation |
Liang S.-H.,Anhui Huainan Pingwei Power Company Ltd
Gaoya Dianqi/High Voltage Apparatus | Year: 2012
Aiming at lightning accidents in 35 kV substations in a certain region, U 50% flashover voltage tests for the insulators on incoming line and field investigation were conducted, and severe defect in insulation coordination was found in the substations in this region, i.e. higher insulation level of transmission line and resistivity of the mountain soil cause the lightning invasion wave on the line not to attenuate sufficiently, and cause the lack of lightning discharge channel, which results in frequent lightning strike damages on the main transformers in 35 kV substations. In order to solve the lightning strike problem, a protection scheme is proposed in this paper by installing gap-adjustable lightning protection device in parallel on the insulators on incoming line and adopting arrester at substation. The insulation coordination of the device and insulator string as well as the design principle is analyzed, and the gap distance of the gap-adjustable lightning protection device for the region is designed through theoretical calculation and test. Simulation via the power system electromagnetic transient program ATP-EMTP shows that the gap-adjustable lightning protection device is feasible and effective. Considering that the gap is easy to induce clipped wave, which may significantly impact voltage, a reactor is concatenated to incoming line of transformer for inhibiting the effect of clipped wave over-voltage.
Wang Q.,Guangdong Power Grid Corporation |
Pan X.-X.,North China Electrical Power University |
Chen Y.,Maintenance Company of Anhui Electrical Power Corporation |
Yang F.-Y.,Guangdong Power Grid Corporation |
Lin L.,North China Electrical Power University
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2014
Accurate model of the wind farm is the basis for the analysis of wind power integrating grid. Firstly, the comparison is made between the standard power characteristic curve and the measured scatter plot of wind speed-active power for DFIG. The wind speed-active power model is proposed based on the measured data. For the wind speed differences of wind turbines in large wind farm caused by complex terrain and the crew irregular arrangement, K-means clustering algorithm is used for the equivalent wind speed model of the whole wind farm. Then the wind speed-active power model of wind farm based on measured data is proposed. Taking an actual wind farm as example, K-means clustering algorithm is used to the clusters division. Result shows that the division by wind speed is different from that by location of wind turbine units. Finally, to verify the effectiveness of the new wind speed-active power model, the error comparative analysis is made between the new model and the traditional model. Result shows that the accuracy of the model is greatly improved with the proposed method.
Shao J.,Maintenance Company of Anhui Electrical Power Corporation |
Hu W.-Y.,Maintenance Company of Anhui Electrical Power Corporation |
Jia F.-M.,Maintenance Company of Anhui Electrical Power Corporation |
Hu Y.-R.,Maintenance Company of Anhui Electrical Power Corporation |
Ma X.-W.,Maintenance Company of Anhui Electrical Power Corporation
Gaoya Dianqi/High Voltage Apparatus | Year: 2013
Live detection of electrical equipment can be conducted with infrared thermal imaging technology. This paper discusses the application of the infrared thermal imaging technology to the condition-based maintenance of electrical equipment via some instances of infrared temperature measurement. The temperature distribution of insulation media within electrical equipment can be measured by the infrared thermal imaging technology to find insulation failure and equipment defects of electrical equipment in operation, and further to track and analyze operational status of the equipment. Thus, necessary measures can be taken to avoid accidents and ensure safe and stable operation of electrical equipment. The infrared thermal imaging technology plays an important role in the condition-based maintenance of electrical equipment in power transmission grid.