一种新型小电流接地系统单相接地故障检测装置的设计

A New Design for Single-phase-to-earth Fault Detection Device in Neutral Point Ineffectively Grounded System

本文针对小电流接地系统存在的选线问题,在深入分析小电流接地系统发生单相接地故障时的暂态和稳态过程电气量特征的基础上,设计了一套基于综合判据的小电流接地选线装置。利用DSP芯片的优越的数字信号处理功能和快速的运算速度,很好的解决了传统的MCU的运算速度低的问题,实现了包括注入信号法在内的小电流接地综合智能选线算法。其软件判据为综合暂态和稳态判据的综合判据,提高了选线速度和性能。实践结果表明,该装置运算速度快,抗干扰能力强,运行稳定,具有良好的性价比,是小电流接地电网中一种实用的选线平台。

According to the fault line selection problem in neutral point ineffectively grounded system, this paper analyses fault feature of single-phase grounding and designs a line selection device of neutral point ineffectively grounded system based on integrated criterion. Compared with the conventional MCU, the DSP owns superior digital signal processing function and high calculating speed which make intellective line selection algorithm possible. At mean time, transient and steady criterions are integrated to improve the speed and capability of fault line selection. The operation results show that this device has fast calculation speed, excellent capacity of resisting disturbance and good running record. The solution proves that the device is an ideal earth-fault selection platform for its high performance-price ratio.