Single‐pole fault protection for MMC‐HVDC transmission line based on improved transient‐extracting transform

Abstract

Due to the overload limitation of the converters, the main protection for DC lines of High Voltage Direct Current based on Modular Multilevel Converter (MMC-HVDC) requires ultra high speed for fault detection. The protection principles of single-terminal traveling-wave can meet this requirement. Such protection principles which are usually constructed by transmission theory of fault traveling-wave have a clear physical concept and do not depend on boundary components. Almost all of these principles are dependent on accurately detecting the arrival time of the traveling-waves. Thus, it is urgent to research a new time-frequency analysis method with a high time resolution to identify the arrival time of traveling-wave. This paper introduces Transient-Extracting Transform (TET) to detect traveling-wave and improves it fully considering the fault traveling-wave characteristics of DC lines. The time resolution of improved TET is greatly increased

Research on online monitoring and anti-dance technology of transmission line dance based on wide-area information transmission

“…When the transmission line dances at a slower speed, the motion of the target spacer bar between two neighboring frames is maintained at a low level around [1,3]. When the target transmission line as well as the faster speed dance, if it is assumed that the overlap rate of the target frame and the predicted frame is more balanced as the tracking success, then the Wide Area Information Transmission Technology tracks the motion amplitude at [7,11], and the level of the dance track maintains a balanced level, so it is seen that the Wide Area Information Transmission Technology has a better success rate in the online monitoring of the transmission line dance. In order to test the processing speed of WANIT, WANIT and other technologies are run on the same platform 150 times, and the average number of frames processed per second is taken for each time.…”

“…Grasping the actual dancing situation of transmission lines, it is possible to make targeted decisions to avoid accidents [4][5]. Therefore, the dance reconstruction of transmission lines has important research value [6][7].…”

Transient Extraction Transform Based Fault Location Method with Enhanced Accuracy

“…That is to say, the time-varying characteristics of travelling wave frequency change can be accurately displayed. The theoretical deduction is as follows [12].…”