ABSTRACT

This study aims to develop a new relaying scheme for the complete protection of transmission line based on only voltage data. Fault detection and classification is obtained from the fundamental component of the voltage signal collected from one end of the line. Magnitudes of positive sequence component of voltage signals from both ends of the line have been considered for fault location. As only magnitude of voltage signal is used, the requirement for data synchronization can be avoided, and the error caused by current transformers (CT) is eliminated. Moreover, positive sequence components exist for all types of faults, unlike negative sequence components. Hence, all types of faults can be located. Fuzzy decision approach has been proposed to avoid computationally expensive training of expert systems. The proposed scheme has been tested for different dynamic situations in MATLAB/Simulink software. The superiority of the scheme has been established by considering coupling capacitor voltage transformer (CCVT) transient error, weak infeed condition, change of transmission voltage level and line loading.

摘要

本研究旨在开发一种仅基于电压数据的输电线路完整保护的新继电方案。故障检测和分类是从线路一端采集的电压信号的基波分量中获得的。考虑了线路两端电压信号正序分量的大小进行故障定位。由于只使用电压信号的幅度，可以避免数据同步的要求，并且消除了由电流互感器（CT）引起的误差。此外，与负序分量不同，所有类型的故障都存在正序分量。因此，可以定位所有类型的故障。已经提出了模糊决策方法来避免计算昂贵的专家系统训练。所提出的方案已经在 MATLAB/Simulink 软件中针对不同的动态情况进行了测试。该方案的优越性是通过考虑耦合电容式电压互感器（CCVT）的瞬态误差、弱馈电条件、输电电压电平的变化和线路负载等因素确定的。