ABSTRACT

The loss of excitation (LOE) is a very common fault in synchronous machine operations and can be caused by a short circuit in the field winding, unexpected operation of the field breaker. Several methods are proposed to detect LOE, but most of them are impedance-based. It is possible that these methods will not be able to identify between LOE and stable power swing (SPS). In this paper, a new method for LOE fault detection is presented, which is designed based on the derivative of the terminal voltage and the derivative power angle of the synchronous generator. According to the proposed idea, complete simulation studies have been performed by considering different fault modes in the synchronous generator and the different conditions governing it to check the accuracy of the performance. These studies show that the proposed algorithm is faster and more accurate in detecting LOE fault. It also has higher security in distinguishing LOE fault from SPS.

摘要

失磁 (LOE) 是同步电机运行中非常常见的故障，可能是由励磁绕组短路、励磁断路器意外操作引起的。人们提出了多种检测 LOE 的方法，但大多数都是基于阻抗的。这些方法可能无法识别 LOE 和稳定功率摆幅 (SPS)。本文提出了一种基于同步发电机端电压导数和导数功率角的LOE故障检测新方法。根据所提出的想法，考虑同步发电机的不同故障模式和不同的控制条件进行了完整的仿真研究，以检查性能的准确性。这些研究表明，所提出的算法在检测 LOE 故障方面更快、更准确。在区分LOE故障和SPS方面也具有更高的安全性。