Spectrum Comparative Study of Commutation Failure and Short-Circuit Fault in UHVDC Transmission System
Abstract: When commutation
failure occurs in UHVDC transmission system, the transient process of DC
voltage and current are similar to grounding short-circuit fault. In order to
differentiate them effectively, the paper introduces mathematical morphology
methods to analysis the spectrum of transient current. Base on Yunnan-Guangzhou
kV UHVDC transmission system, the paper simulates the commutation failure and
DC line short-circuit fault under different fault conditions in
PSCAD/EMTDC. By modified morphology
filter, the transient signal of DC () is decomposed into six scales, and morphological
characteristics of aerial mode component of
is analyzed under different scales. The simulation results show that
when DC line short-circuit faults occurs, wherever in the rectifier side, in
the DC transmission line midpoint or in the inverter side, the aerial mode
component of have more high frequency
weight in ~ and decays gradually; When commutation failures, which are caused
by the inverter side AC system single-phase grounding fault, phase to phase
fault, three phase grounding fault or the inverter side transformer ratio increased, the aerial mode component of have less frequency weight in.
Keywords: UHVDC, commutation
failure, DC line short circuit fault, PSCAD/EMTDC, morphology
Author: Shi-long Chen,
Jun-xiang Rong, Gui-hong Bi, Xing-wang Li, Rui-rui Cao
Journal Code: jptkomputergg140095
