超高速暂态方向继电器的研究

STUDY OF ULTRA-HIGH-SPEED TRANSIENT-BASED DIRECTIONAL RELAY

行波方向保护已研究了多年,但其本质上仍要受故障初始角、反射波等因素的影响。该文提出一种新型的方向保护核心元件——暂态方向继电器,它基于故障发生后一段时间内正向行波分量与反向行波分量间的能量大小关系来识别故障方向。该继电器的实用算法采用了适合暂态信号处理的小波技术,由小波多分辨分析来提取行波分量,并将行波分量的能量表征成小波变换谱能量(WTSE)。大量EMTP仿真试验表明:该继电器能可靠、灵敏、超高速地动作,其性能不受故障初始角、故障类型、故障距离、过渡电阻与电弧、母线接线方式的影响。以该继电器构成的超高速方向保护将具有很强的实用价值。

The traveling-wave-based directional protection schemes have been studied for years, but essentially these protection performances are still influenced by low inception angles, reflective traveling-waves, etc. This paper presents a novel transient-based directional relay, the kernel unit of directionalprotection, for transmission line. The relay identifies fault direction by means of comparing the energy magnitude of the forward traveling-wave component with that of the backward. The relay algorithm is designed with the wavelet technology that fits for transient signal analysis. Traveling-wave components are extracted from fault-induced signals with wavelet multi-resolution analysis, and the wavelet transform spectral energy (WTSE) represents the energy of traveling-wave component. Numerous EMTP simulation tests show that this proposed relay response is reliable, sensitive and ultra-high-speed. Meanwhile the relay performance can endure the influences of various factors, including different fault inception angles, fault distances, fault types, fault path resistances, fault arcing, feeder modes on bus bar. The ultra-high-speed directional protection composed of this proposed relay will be worthy of application greatly.