Duffing振子信号检测方法用于配电网单相故障接地保护

DUFFING OSCILLATOR SIGNAL DETECTION METHOD APPLIES TO THE SINGLE-PHASE TO GROUND FAULT PROTECTION IN DISTRIBUTION SYSTEMS

Duffing振子信号检测技术利用混沌系统的分岔特性来检测外界信号,将待测信号作为Duffing方程周期策动力的摄动,利用初值敏感性可以获得很高的测量灵敏度和良好的抗噪性能。基于Duffing振子信号检测技术提出一种新型的单相接地故障选线方法。故障后故障线路和非故障线路零序电流将使Duffing振子系统分别处于大周期或混沌状态,据此可以选出故障线路,从而将选线问题转化为待测故障信号从无到有的敏感检测问题,简化了选线过程,抗噪性能好,提高了接地保护的灵敏度。文中给出了该方法的具体实现步骤。采用虚拟仪器技术,开发了基于混沌选线方法的小电流接地系统单相接地故障选线仪。实验室物理模拟实验和现场录波数据分析结果证明了该方法的可行性和有效性。

The chaotic oscillator detection method applies the bifurcation behavior of the driven Duffing oscillator to detecting the signals. The chaotic system is sensitive to certain signals and immune to noise, thus the performance is propitious to the detection sensitivity and anti-interference capability. In this paper, a brand new method for single-phase-to-ground fault selection based on the Duffing oscillator signal detection technique is presented to improve the relaying sensitivity and veracity. Fault line is selected according to its state, big cycle or chaotic, after the motion of the chaotic system. And then the problem of fault line selection is transformed to sensitivity detection of fault signal, simplifying the fault line selection process. The realization is expounded in details. Furthermore, based on Lab VIEW virtual instrument technology, the chaotic single-phase-to-ground fault protection is developed. The results prove the feasibility and effectiveness.