基于中阻抗接地法的谐振接地系统综合选线策略研究

Research of the comprehensive fault detection method based on moderate value resistance for neutral resonant grounded network

中性点谐振接地系统由于消弧线圈的补偿电流作用,在发生单相接地故障时,故障线零序电流幅值小,且零序电流方向差异化特征不明显,给选线判别带来了不便。本文提出了一种基于中阻抗接地法的综合选线策略,融合中阻抗接地方式优势,结合暂态信号可靠度评价体系,综合故障零序电流稳态、暂态特征信号进行故障线路判别,可有效提升选线装置正确率。并在此基础上,针对该选线策略制定了系统的现场试验方法,确保了投运装置的可靠性。

In the neutral resonant grounding system, the compensation currents of the arcextinguish coil would decrease the zero-sequence current of the fault line when the ground fault happened, which would made the direction characteristic of the zero-sequence unconspicuous. A new comprehensive fault detection method based on moderate value resistance was put forward in this paper, which combined the the steady current state with the moderate value risistance and transient current state without the moderate value risistance to promote the accuracy of the fault detection. Meanwhile, this paper designed a site test method for the fault detection protection device.