CAJ | 학술논문

特高压直流输电线路受到雷击未故障时，极线上电压行波围绕直流分量上下交替变化，与轴线电压相关度趋近于1。此特征可作为识别雷击干扰的判据。雷击故障时，雷电波中有大量高频分量，绝缘闪络后，迅速衰减；接地故障时，短路电压行波由附加电源产生，高频分量少。雷击故障最终呈现接地故障特征，经小波变换后，中低频分量与接地故障相近，故雷击故障高频能量与中低频能量比值较接地故障时大。据此特征可用来识别雷击故障和接地短路故障。利用云广±800 kV直流输电模型，采用5 ms时窗，进行了大量的EMTP暂态仿真，验证了该方法的有效性。
특고압직류수전선로수도뢰격미고장시，겁선상전압행파위요직류분량상하교체변화，여축선전압상관도추근우1。차특정가작위식별뢰격간우적판거。뢰격고장시，뇌전파중유대량고빈분량，절연섬락후，신속쇠감；접지고장시，단로전압행파유부가전원산생，고빈분량소。뢰격고장최종정현접지고장특정，경소파변환후，중저빈분량여접지고장상근，고뢰격고장고빈능량여중저빈능량비치교접지고장시대。거차특정가용래식별뢰격고장화접지단로고장。이용운엄±800 kV직류수전모형，채용5 ms시창，진행료대량적EMTP잠태방진，험증료해방법적유효성。
When thunderbolt directly strikes on UHVDC transmission line and does not lead to line fault, the voltage traveling wave on polar line alternately fluctuates around the DC component and the correlation degree between the voltage traveling-wave and the direct voltage line is close to 1. Such a feature can be used as the criterion to identify lightning disturbance. When lightning fault occurs, there are lots of high-frequency components in lightning wave, which attenuates quickly after the insulation is broke down; when earth fault occurs, the traveling wave of short-circuit voltage is caused by additional power supply, so there are few high-frequency components in it. The lightning stroke fault finally takes on the feature of earth fault, and after the wavelet transform the medium-and low-frequency components due to lightning stroke are similar to those of earth fault, thus the ratio of high-frequency components caused by lightning stroke to medium-and low-frequency components is larger than that of earth fault, accordingly such a feature can be used to distinguish lightning stroke fault from earth fault. Utilizing the model of ±800 kV UHVDC power transmission project from Yunnan to Guangdong and adopting the time window with the width of 5 ms, a lot of EMTP simulation are performed, and simulation results show that the proposed method is effective.