Time filter

Source Type

Xiao P.,Hunan University | Wang F.,Hunan University | Huang F.,Hunan Electrical Power Research Institute | Zhou W.,Hunan Electrical Power Research Institute | And 3 more authors.
Dianwang Jishu/Power System Technology | Year: 2012

In the research on lightning protection performance of transmission line, the calculation accuracy of line lightning resisting level directly depends on the criterion of insulation flashover, for this reason, according to physical discharge mechanism of long air gap and combining with structural features of insulator string an insulator string flashover model based on continuous leader development is built. Using the built model, the voltage-time characteristics is calculated and compared with measured data to verify the accuracy of the built model. Taking 500kV transmission line for example, the lightning resisting levels of flashback under different flashover criteria are calculated, and combining with operational experiences of high-voltage transmission lines home and abroad the accuracy and application scope of each criterion are analyzed. Using the built model, the influences of tower impulse earthing resistance and the types of insulator strings on line lightning resisting level are further researched. Results of the research show that comparing with traditional criterion for leader-caused flashover, in which only the length of insulator string is considered and the attention is not fully paid to concrete structure of the string, the built criterion for insulator flashover based on the development of continuous leader is more accurate.

Luo Y.,Xian Jiaotong University | Liu H.,Xian Jiaotong University | Wang M.,Xian Jiaotong University | Xin X.,Xian Jiaotong University | And 5 more authors.
Przeglad Elektrotechniczny | Year: 2013

An online monitoring system of corona loss of high voltage transmission lines based on metalized membrane method is developed in this paper. The system includes 3 components: the upper computer, the conductor voltage acquisition module and the corona leakage current acquisition module. The corona leakage current acquisition module is set on the high voltage line. The transmission line is covered by a certain length of thin metalized membrane. The sampling resistance is put paralleling between metal layer and bundle conductor. The conductor voltage acquisition module is set in transformer substation. The two modules are synchronized by the rising edge of Pulse Per Second (PPS) emitted by Global Position System (GPS), and the data is sent to the public port of mobile telephone network by General Packet Radio Service (GPRS). The remote upper computer gets the data and calculates corona loss of each bundle conductor by visiting public port. The experiment results show that the system can monitor the corona loss accurately. The whole study is helpful in the further research of UHV transmission line's corona in different environment and weather.

Wang M.,Xian Jiaotong University | Liu H.,Xian Jiaotong University | Luo Y.,Xian Jiaotong University | Zhang Y.,Xian Jiaotong University | And 3 more authors.
Gaoya Dianqi/High Voltage Apparatus | Year: 2014

Based on the presented metallized membrane method for measuring corona leakage current of AC/DC transmission line, an on-line monitoring system is developed, which includes three components, i. e. the upper computer, the lead line voltage acquisition module, and the corona leakage current acquisition module. The corona leakage current acquisition module is located on overhead line to sample the voltage signal translated from corona leakage current on the resistor paralleled between respective bundle conductor and metallized membrane coat. The lead line voltage acquisition module is put in transformer substation for sampling the conductor voltage. Both modules are synchronized in sampling by the rising edge of PPS (pulse per second) emitted by the global position system (GPS), and their data are sent to the public port of mobile telephone network with GPRS wireless telecommunication. The data of conductor voltage and corona currents of the bundle conductors stored in the public port are accessed by remote upper computer to calculate the corona loss of each metallized coat bundle conductor in unit length, and to further calculate the corona loss of whole line. Experimental results show that the proposed system is accurate. This study may provide a foundation for future research of corona and its effect of high voltage transmission line.

Discover hidden collaborations