电流行波差动式母线保护的研究

为避免电流互感器暂态饱和的影响，研究了一种基于暂态电流行波的新型母线保护。在对母线上线路各相电流行波差动量的故障特征进行分析的基础上，为提高判别母线区内外故障的灵敏度，又引入各相电流行波的制动量，提出一种具有比率制动特性的电流行波差动式母线保护，及其基于小波变换的实用比率判据。理论分析和EMTP仿真表明该母线保护快速、灵敏、可靠，基本不受故障类型、故障过渡电阻、故障距离和故障初始角的影响。

STUDY ON THE CURRENT TRAVELING-WAVE DIFFERENTIAL BUS PROTECTION

To avoid the influence of the current transformer transient saturation, this paper studies a novel bus protection based on the transient current traveling-waves. On the basis of analyzing the fault feature of the differential traveling-wave in each phase of the transmission lines connected to the protected bus, the restraint traveling-wave in each phase is introduced to improve the sensitivity of distinguishing bus internal faults from external faults. Accordingly this paper presents the bus protection of differential traveling-waves with the percentage bias restraint characteristic, and then proposes the bus protection practicable criterion using the wavelet transform. The theoretical analysis and EMTP simulation show that the bus protection operates rapidly, sensitively and reliably, and its performance can endure the influences of various fault types, fault path resistances, fault positions and fault inception angles.