Study On HVDC Transmission Line Protection Based On The Analysis Of Traveling Wave

Along with the rapid development of computer technology, modern control technology, power electronic technology and related technology, the development of high-voltage direct current (HVDC) transmission technology over the past six years has become increasingly mature. HVDC is very suitable for long-distance, high-capacity power transmission which is in line with the characteristics of our country’s power transmission. So in recent years, HVDC is widely used and become an important part in the power system in our country. In the actual operation of the HVDC project, there are still not high reliability and ease of misprotection protection issues, so the protection of HVDC research for the current the steady operation of power grid and has profound significance for the development of HVDC transmission technology.This paper first introduces the development and characteristics of high-voltage direct current transmission, status and trends of development of HVDC traveling wave protection; on the structure of the HVDC and traveling wave produced in the process of movement characteristics are analyzed; introduces the principle of the method used in HVDC transient traveling wave fault location, also compared and discussed in depth the performance of ABB and SIEMENS traveling wave protection scheme.Secondly based on HVDC transmission standards set by CIGRE, the use of PSCAD/EMTDC simulation software build a simulation model of a single-stage12-pulse HVDC system, and set up different types of fault lines inside and outside the region for simulation. While the filtering characteristics of the filter and the reactor were analyzed, this paper describes the theoretical basis for the protection criterion based on the frequency and energy.Finally this article introduces and compares the wavelet analysis and Hilbert-huang method which is used to analysis the transient traveling wave, and put the two using in the simulation of two-terminal HVDC transmission distance; put forward a kind of based on Hilbert-huang the fault judgement method for HVDC transmission area inside and outside. Comprehensively we form a HVDC transient travelling wave protection program based on Hilbert-huang. Through simulating and calculating, it has been showed that the method can accurately distinguish the area of failure with high precision in fault location, the results prove the feasibility of the protection scheme.