电网技术
電網技術
전망기술
POWER SYSTEM TECHNOLOGY
2013年
10期
2850-2854
,共5页
局部放电%特高频法%GIS结构尺寸%频谱分布%有限时域差分
跼部放電%特高頻法%GIS結構呎吋%頻譜分佈%有限時域差分
국부방전%특고빈법%GIS결구척촌%빈보분포%유한시역차분
partial discharge%ultra high frequency%structure size of GIS%frequency spectrum%finite difference time domain
由于气体绝缘组合电器(gas insulated substation, GIS)管道中局部放电激发的特高频信号以高次模分量为主，电磁波高次模态的截止频率取决于内导体和外壳的直径，因此 GIS 的结构尺寸将影响特高频信号的特征。首先通过改变220 kV GIS内导体的直径，运用仿真和试验研究GIS内导体的尺寸对局部放电信号的影响，分析信号幅值、持续时间频谱特征以及时频分布随着内导体尺寸改变的变化规律。然后分析了1000 kV GIS中所测局部放电的特高频信号。发现当GIS尺寸变化，导致高次模截止频率降低时，局部放电信号的持续时间将变长，幅值衰减变缓，而且峰值将升高。GIS 结构尺寸还影响局部放电信号频谱，由于高次模色散的影响，在高次模的截止频率处，信号频谱将出现显著的增长。
由于氣體絕緣組閤電器(gas insulated substation, GIS)管道中跼部放電激髮的特高頻信號以高次模分量為主，電磁波高次模態的截止頻率取決于內導體和外殼的直徑，因此 GIS 的結構呎吋將影響特高頻信號的特徵。首先通過改變220 kV GIS內導體的直徑，運用倣真和試驗研究GIS內導體的呎吋對跼部放電信號的影響，分析信號幅值、持續時間頻譜特徵以及時頻分佈隨著內導體呎吋改變的變化規律。然後分析瞭1000 kV GIS中所測跼部放電的特高頻信號。髮現噹GIS呎吋變化，導緻高次模截止頻率降低時，跼部放電信號的持續時間將變長，幅值衰減變緩，而且峰值將升高。GIS 結構呎吋還影響跼部放電信號頻譜，由于高次模色散的影響，在高次模的截止頻率處，信號頻譜將齣現顯著的增長。
유우기체절연조합전기(gas insulated substation, GIS)관도중국부방전격발적특고빈신호이고차모분량위주，전자파고차모태적절지빈솔취결우내도체화외각적직경，인차 GIS 적결구척촌장영향특고빈신호적특정。수선통과개변220 kV GIS내도체적직경，운용방진화시험연구GIS내도체적척촌대국부방전신호적영향，분석신호폭치、지속시간빈보특정이급시빈분포수착내도체척촌개변적변화규률。연후분석료1000 kV GIS중소측국부방전적특고빈신호。발현당GIS척촌변화，도치고차모절지빈솔강저시，국부방전신호적지속시간장변장，폭치쇠감변완，이차봉치장승고。GIS 결구척촌환영향국부방전신호빈보，유우고차모색산적영향，재고차모적절지빈솔처，신호빈보장출현현저적증장。
The main component of ultra high frequency (UHF) signal induced by the partial discharge (PD) in GIS is the high order mode. The cutoff frequency of the high order modal of the electromagnetic (EM) wave depends on the diameters of the inner conductor and enclosure of GIS, hence the structure size of GIS greatly impacts the future of PD signal. Firstly, by changing the diameter of inner conductor of a 220 kV GIS, the impact of the inner conductor diameter on PD signal is researched by simulation using finite difference time domain (FDTD) method and experiments, thus the varying regularities of signal amplitude, its duration, frequency spectrum characteristics and time-frequency distribution with the variation of the size of inner conductor are analyzed. The measured UHF signal excited by PD in 1 000 kV GIS is analyzed, and it is found that when the variation of GIS size leads to the decrease of cutoff frequency of the high order modal, the duration of the PD will be longer, the amplitude attenuation will slow down and the peak value will increase. In addition, there was remarkable influence of the cutoff frequency on the frequency spectrum of PD signal. Besides, the structural size of GIS impacts on the frequency spectrum of PD signal, due to the influence of high order modal dispersion, the signal frequency spectrum will suddenly increase at the cutoff frequency of high order modal.
