CAJ | 학술논문

分析了不同运行方式、零序互感强弱及不同故障位置下同塔双回线路外部接地故障和内部接地故障时零序电流的分布规律。外部接地故障主要考虑了同塔双回线路零序阻抗不同的影响，内部接地故障则主要考虑了双回线路并列运行、一回线路充电热备用、一回线路接地挂检等运行方式下零序互感及故障位置的影响。由于同塔线路间零序电流同向流动的“零序助磁”与反向流动的“零序去磁”效应，造成零序电流分布规律的异变，极端情况下将导致零序电流I段保护的超越。结合广东电网实际算例，提出了避免零序电流I段保护超越的整定措施，零序I段的整定应考虑运行方式、互感强弱及故障位置的综合影响，以避免同塔线路故障，相邻健全线路零序电流I段受互感影响而超越误动。
분석료불동운행방식、령서호감강약급불동고장위치하동탑쌍회선로외부접지고장화내부접지고장시령서전류적분포규률。외부접지고장주요고필료동탑쌍회선로령서조항불동적영향，내부접지고장칙주요고필료쌍회선로병렬운행、일회선로충전열비용、일회선로접지괘검등운행방식하령서호감급고장위치적영향。유우동탑선로간령서전류동향류동적“령서조자”여반향류동적“령서거자”효응，조성령서전류분포규률적이변，겁단정황하장도치령서전류I단보호적초월。결합엄동전망실제산례，제출료피면령서전류I단보호초월적정정조시，령서I단적정정응고필운행방식、호감강약급고장위치적종합영향，이피면동탑선로고장，상린건전선로령서전류I단수호감영향이초월오동。
The distribution regularity of zero-sequence current, which appears during external and internal grounding faults occurred in double-circuit transmission lines on the same tower under different operation modes, different zero-sequence mutual inductance and different fault locations, is analyzed. For external grounding faults, the impact of different zero-sequence impedance of double-circuit transmission lines on the same tower is mainly considered; for internal grounding faults, the impacts of zero-sequence mutual inductances and fault locations under following conditions are considered： parallel operation of both transmission lines; one transmission line is energized and in the stand-by state while the other one is artificially grounded for the maintenance. The effects of ＂zero-sequence magnetic assist＂ and ＂zero-sequence degaussing＂, which are caused by the flowing of zero-sequence currents of both transmission lines on the same tower in the same direction and by those in the opposite direction respectively, lead to variation of distribution regularity of zero-sequence currents, and in extreme circumstance the out-of-limit of the first zone of zero-sequence over-current protection may occur. Based on practical calculation examples of Guangdong power grid, the setting measures are put forward to avoid the out-of-limit of the first zone of zero-sequence over-current protection for double-circuit transmission lines on the same tower. It is also proposed that in the setting of the first zone of zero-sequence over-current protection for double-circuit transmission lines on the same tower, the comprehensive effects of operation modes of double-circuit transmission lines on the same tower, the extent of zero-sequence mutual induction and fault locations should be taken into account to avoid the malfunction of the first zone of zero-sequence over-current protection of adjacent healthy transmission lines due to the affect of mutual induction while grounding fault occurs in another circuit of transmission lines .