小电流接地系统接地型早期故障扰动特征分析

早期故障用于描述系统中不会导致继电保护动作的瞬时性自恢复故障扰动。基于对早期故障扰动的检测识别可实现对配网的故障预测和预警,对于提升供电可靠性有重要意义。受中性点接地方式影响,小电流接地系统中早期故障将有不同表现形式。针对小电流接地系统特点及其运行要求,分别从等效电路及仿真建模两方面,对该类系统中接地型早期故障的表现形式及其电气量变化特征进行了分析和总结。结果表明,小电流接地系统中接地型早期故障分为"单相接地型"和"异名相两点接地型",同时总结了各种情况下早期故障扰动波形的变化特征。仿真和部分现场故障录波数据证明了分析结论的正确性,研究结论将为小电流接地系统早期故障检测识别及故障预测预警提供重要理论支撑。

Grounded incipient fault analysis in a non-solidly grounding system

Incipient faults are used to describe transient self-recovery faults that will not cause relay protection actions in the system. Fault prediction and early warning of distribution network faults can be realized based on incipient fault detection and identification. This is of significance for improving power supply reliability. Affected by the neutral grounding method, incipient faults in a non-solidly grounding system manifest in different ways. For the characteristics and operating requirements of such a system, this paper analyzes and summarizes manifestations and characteristics of grounded incipient faults quantitatively from the equivalent circuit and simulation modeling. Results indicate that grounded incipient faults are divided into single-phase-to-ground fault and two-point grounding fault in two phases, and characteristics of incipient fault waveforms are summarized. The conclusions are verified by simulation and field data, and will provide theory and data support for detection and identification of incipient faults in non-solidly grounding system, as well as fault prediction and early warning. This work is supported by the National Key Research and Development Program of China (No. 2020YFF0305800) and Sichuan Applied Basic Research Project (No. 2020YJ0012).