Fault Line Identification of HVDC Transmission Line by Frequency Spectrum Correlation Based on Capacitive-Coupling and Magnetic-Field-Sensing.

摘要

The proliferation of high-voltage direct current (HVDC) system is growing fast thanks to its distinct technical advantages such as long-distance bulk power delivery at a lower cost, asynchronous interconnections, and reduced power loss [1]. The protection system of HVDC system must detect, identify and isolate the fault quickly to keep the system stable by isolating only the components that are under fault, whilst leaving the rest of the network in operation [2]. However, the criteria of under-voltage and voltage derivative protection systems may fail because there also arises a large voltage drop/variation on the healthy transmission line due to the electromagnetic coupling between HVDC transmission lines incurred by the sharp transient current from the faulty one [3, 4]. Thus the healthy line could be mistakenly identified and isolated, resulting in further disruption and delaying system restoring time. In order to distinguish the healthy HVDC transmission line from the faulted one, a fault line identification technique based on the frequency spectrum correlation is developed in this paper.