TY - JOUR
T1 - Distance protection of multiple-circuit shared tower transmission lines with different voltages
T2 - Part I: Fault current magnitude
AU - Silva, Filipe Miguel Faria da
AU - Bak, Claus Leth
N1 - This paper is a postprint of a paper submitted to and accepted for publication in IET Generation, Transmission & Distribution and is subject to Institution of Engineering and Technology Copyright. The copy of records is available at the IET Digital Library
PY - 2017/7
Y1 - 2017/7
N2 - Multiple-circuit transmission lines combining different voltage levels in one tower present extra challenges when setting a protection philosophy, as faults between voltage levels are possible. This study presents a detailed theoretical analysis of such combined faults, including the development of a formula for estimating the magnitude of the short-circuit current. It is demonstrated that if the faulted phase from the higher voltage level leads the faulted phase from the lower voltage level, a distance relay at the higher voltage level sees the fault in the forward direction, whereas a distance relay at the lower voltage level sees the fault in the reverse direction. The opposite happens if the lower voltage level leads the higher voltage level. It is also demonstrated that the magnitude of fault currents of combined faults is normally slightly larger than of equivalent single-phase-to-ground fault at the higher voltage level. Part II will continue the research work and focus in the fault loop impedance RX diagrams.
AB - Multiple-circuit transmission lines combining different voltage levels in one tower present extra challenges when setting a protection philosophy, as faults between voltage levels are possible. This study presents a detailed theoretical analysis of such combined faults, including the development of a formula for estimating the magnitude of the short-circuit current. It is demonstrated that if the faulted phase from the higher voltage level leads the faulted phase from the lower voltage level, a distance relay at the higher voltage level sees the fault in the forward direction, whereas a distance relay at the lower voltage level sees the fault in the reverse direction. The opposite happens if the lower voltage level leads the higher voltage level. It is also demonstrated that the magnitude of fault currents of combined faults is normally slightly larger than of equivalent single-phase-to-ground fault at the higher voltage level. Part II will continue the research work and focus in the fault loop impedance RX diagrams.
U2 - 10.1049/iet-gtd.2016.1763
DO - 10.1049/iet-gtd.2016.1763
M3 - Journal article
SN - 1751-8687
VL - 11
SP - 2618
EP - 2625
JO - IET Generation, Transmission & Distribution
JF - IET Generation, Transmission & Distribution
IS - 10
ER -