Abstract

Power swing due to the disturbance in the power system is a cause of the untrue operation of protective elements. Previously, many blackouts have been perceived and recorded due to reactive power mismatch problems, active power mismatch problems, and system venerability. The power system stability is usually disturbed due to the sudden loss of transmission lines, generators, and transformers. The present work proposes the concept of apparent power transient stability due to the transient disturbance. By considering that concept, we propose a power swing blocking algorithm to prevent mal-operation of distance relay. The proposed algorithm uses the relative frequency between the sending end bus and system standard frequency with simultaneous measurement of voltage decay of the transmission line. We have implemented the proposed algorithm on a single machine infinite system (SMIB) and the IEEE-9 bus system to compare the power swing detection and blocking performance with mho type out of step relay in different power swing conditions. In the end, results show the accurate performance, simplicity, reliability, and correct co-ordination of the proposed relay with distance relay, which ultimately solved the issue of mal-operation of zone-3 distance relay during complex power swing conditions.

摘要

由于电源系统中的干扰而引起的功率摆幅是保护元件操作不正确的原因。以前，由于无功功率不匹配问题，有功功率不匹配问题和系统极高的可靠性，人们已经意识到并记录了许多停电情况。电力系统的稳定性通常由于传输线，发电机和变压器的突然丢失而受到干扰。本工作提出了由于瞬态干扰而引起的视在功率瞬态稳定性的概念。通过考虑该概念，我们提出了一种功率摆幅阻塞算法，以防止距离继电器误操作。该算法利用发送端总线与系统标准频率之间的相对频率，同时测量传输线的电压衰减。我们已经在单机无限系统（SMIB）和IEEE-9总线系统上实现了所提出的算法，以比较不同功率摆幅条件下mho型失步继电器的功率摆幅检测和阻塞性能。最后，结果表明了所提出的继电器与距离继电器的精确性能，简单性，可靠性和正确的配合，最终解决了在复杂的动力摆幅条件下3区距离继电器的误操作问题。