Open AccessApplicability Analysis of Directional Components in AC/DC Hybrid System
Author(s) -
Chenyun He,
Bingyuan Yang
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/514/4/042059
Subject(s) - electrical impedance , symmetrical components , relay , power (physics) , hybrid power , fault (geology) , grid , sequence (biology) , topology (electrical circuits) , computer science , electrical engineering , control theory (sociology) , electronic engineering , engineering , voltage , physics , mathematics , geometry , control (management) , quantum mechanics , artificial intelligence , seismology , geology , biology , genetics , transformer
AC/DC hybrid power grids are more and more widely used in China, and the traditional relay protection directional components have experienced multiple misoperations. The adaptability of traditional directional components in AC / DC hybrid power grids is studied. Traditional direction components are based on fault sequence component network analysis. During the fault, the positive and negative sequence impedance of the AC-DC hybrid power grid is quite different, and the impedance angle of the line impedance and the equivalent impedance of the grid is no longer close to 90°. Misjudgment will occur in the direction component with sudden change, and performance cannot be guaranteed. As a result, directional elements based on the positive and negative sequence current branching coefficients being approximately equal are not suitable for AC/DC hybrid power grids. As for the directional element of the zero sequence principle, since the zero sequence network on the inverter side is relatively stable, its performance is reliable and it can operate correctly.