Forest fire accidents caused by distribution line faults occur frequently,resulting in heavy impacts on people’s safety and social and economic development.Currently,there are few risk assessments for forest fires in...Forest fire accidents caused by distribution line faults occur frequently,resulting in heavy impacts on people’s safety and social and economic development.Currently,there are few risk assessments for forest fires induced by over-head distribution lines,and existing assessment methods may have difficulties in data acquisition.On this basis,a novel as-sessment framework based on an analytic hierarchy process,a Bayesian network and a Fussel-Vesely importance metric is proposed in this paper.The framework combines field research and historical operation and maintenance data to assess the regional-scale risk of forest fires induced by overhead distribution lines to derive the probability of forest fires and to identify high-risk lines and key hazard events in the assessment region.Finally,taking the southern Anhui region as an ex-ample,the annual fire probability of forest fires induced by overhead distribution lines in the southern Anhui region is 5.88%,and rectification measures are proposed.This study provides management with a complete assessment framework that optimizes the difficulty of data collection and allows for additional targeted corrective measures to be proposed for the entire region and route on the basis of the assessment results.展开更多
Transient simulation are more economical and adaptable means of studying lightning overvoltage for overhead distribution line system compared to experiments.A hybrid multi-transmission-line(MTL)-partial element equiva...Transient simulation are more economical and adaptable means of studying lightning overvoltage for overhead distribution line system compared to experiments.A hybrid multi-transmission-line(MTL)-partial element equivalent circuit(PEEC)method proposed for lightning-induced electromagnetic pulse(LEMP)simulation is verified using the rocket-triggered experimental results under a more complex line configuration for the first time.This method can improve computational efficiency while ensuring calculation accuracy.The agreement between experimental and simulation results further validates the adaptability and accuracy of the proposed method,which is adopted to calculate the LEMP on the extended double-circuit parallel unequal length line.The effects of various factors,such as the strike-point location,the amplitude and waveform of the lightning current,the line shape and length on the amplitude of overvoltage and pole flashover along the line are discussed.For double-circuit distribution lines,when lightning strikes the ground in front of centre of circuit I,the three-phase voltage waveforms are similar,all of which are negative or bipolar oscillation waves.The closer the lightning strike point is to the line,the greater the amplitude of the lightning current,and the voltage waveform develops towards a bipolar waveform,but the main peak remains negative.As the amplitude of lightning current increases,the maximum lightning-induced voltage amplitude along the line increases.The LEMP caused by the subsequent return-stroke current is always greater than that caused by the first returnstroke current.When the grounding resistance increases,the maximum voltage peak amplitude along the line remains unchanged.展开更多
基金This work was supported by the National Key Research and Development Program of China(2022YFC3003101)the Fundamental Research Funds for the Central Universities(WK2320000050)the Science and Technology Program of State Grid Anhui Electric Power Co.,Ltd.(521205220001).
文摘Forest fire accidents caused by distribution line faults occur frequently,resulting in heavy impacts on people’s safety and social and economic development.Currently,there are few risk assessments for forest fires induced by over-head distribution lines,and existing assessment methods may have difficulties in data acquisition.On this basis,a novel as-sessment framework based on an analytic hierarchy process,a Bayesian network and a Fussel-Vesely importance metric is proposed in this paper.The framework combines field research and historical operation and maintenance data to assess the regional-scale risk of forest fires induced by overhead distribution lines to derive the probability of forest fires and to identify high-risk lines and key hazard events in the assessment region.Finally,taking the southern Anhui region as an ex-ample,the annual fire probability of forest fires induced by overhead distribution lines in the southern Anhui region is 5.88%,and rectification measures are proposed.This study provides management with a complete assessment framework that optimizes the difficulty of data collection and allows for additional targeted corrective measures to be proposed for the entire region and route on the basis of the assessment results.
基金supported by National Natural Science Foundation of China(No.52507193).
文摘Transient simulation are more economical and adaptable means of studying lightning overvoltage for overhead distribution line system compared to experiments.A hybrid multi-transmission-line(MTL)-partial element equivalent circuit(PEEC)method proposed for lightning-induced electromagnetic pulse(LEMP)simulation is verified using the rocket-triggered experimental results under a more complex line configuration for the first time.This method can improve computational efficiency while ensuring calculation accuracy.The agreement between experimental and simulation results further validates the adaptability and accuracy of the proposed method,which is adopted to calculate the LEMP on the extended double-circuit parallel unequal length line.The effects of various factors,such as the strike-point location,the amplitude and waveform of the lightning current,the line shape and length on the amplitude of overvoltage and pole flashover along the line are discussed.For double-circuit distribution lines,when lightning strikes the ground in front of centre of circuit I,the three-phase voltage waveforms are similar,all of which are negative or bipolar oscillation waves.The closer the lightning strike point is to the line,the greater the amplitude of the lightning current,and the voltage waveform develops towards a bipolar waveform,but the main peak remains negative.As the amplitude of lightning current increases,the maximum lightning-induced voltage amplitude along the line increases.The LEMP caused by the subsequent return-stroke current is always greater than that caused by the first returnstroke current.When the grounding resistance increases,the maximum voltage peak amplitude along the line remains unchanged.
