Open AccessImpact of DG on short circuit current detected by protection
Author(s) -
Jing Gong
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/675/1/012066
Subject(s) - position (finance) , current (fluid) , grid , distributed generation , short circuit , sensitivity (control systems) , relay , electrical impedance , upstream (networking) , computer science , topology (electrical circuits) , electrical engineering , voltage , electronic engineering , mathematics , engineering , physics , telecommunications , renewable energy , business , power (physics) , geometry , finance , quantum mechanics
DG (distributed generation) access causes the change of current detected by the protection, and then affects the sensitivity of the original protection. In order to solve the problem, the influences of DG capacity, DG access location and short-circuit location on short circuit current are analysed in this paper. When the DG capacity and grid-connected position remain unchanged, the unit current method is used to solve the short-circuit current by solving the transfer impedance. The relationship between the change of short circuit position and the impact degree of DG is discussed in detail, and the calculation formula of extreme point is derived. When the DG capacity and short circuit location remain unchanged, the impact of DG grid-connected position on the upstream and downstream current is analysed. The characteristic curve of the impact of DG position change on protection current detection is given, and the impact of DG grid-connected position on protection sensitivity is explained clearly. The conclusion provides an important reference for the selection of DG grid-connected position and the calculation of relay protection in distribution network with DG.