B4-69 Minimizing loss of transmitted power by VSC during overhead line fault

Existing VSC transmission is dominated by underwater and underground cable systems, generally with XLPE-DC cables. As the need for VSC transmission expands, so too will the requirement to minimize transmission costs with overhead transmission where possible. It may not always be likely that VSC transmission can stay overhead. Environmental and agricultural concerns as well as the challenge of obtaining and permitting right-of-way through built-up areas may necessitate reverting to underground and/or underwater cables for a portion of the transmission length.

The overhead transmission line portion will be exposed to adverse atmospheric impacts causing lineto-earth faults which are temporary for the most part which can be cleared and transmission resumed after a period of time. Phase-to-earth temporary faults for ac transmission may apply circuit breaker reclosing within a second or so with either three phase reclosing or single phase reclosing. HVDC LCC transmission with overhead lines has a controlled arc extinction and restart process for temporary faults that is also accomplished within a second. Fast acting HVDC circuit breakers are being developed to emulate in VSC transmission what circuit breakers accomplish in ac transmission for clearing of line faults and recovery to pre-disturbance transmitted power. In each of these ac and dc line-to-earth temporary faults that allow reclose or restart cause power flow disruption for the second or so the reclosing or restarting sequence requires. This WG objective is to investigate how pole-to-earth faults on overhead VSC transmission can be cleared with little or no loss of transmitted power, taking into account portion of the transmission line may be underground or underwater cable.

Terms of Reference (pdf, 62kB)

 WG members:

PathiranaVajira S. CA
OpreaLiliana DE
VaessenPeter NL
Bobrowska-RafałMałgorzata PL
Krontiris Athanasios DE
EbnerGuenter DE
EichhoffDaniel DE
ArnoldAkos DE
ChatterjeeDheeman IN
Dong YunlongCN
Zhu ZheCN
TaiarolPhaedra CA
Mohaddes  Mojtaba CA
Eftekhari Ramin CA
Zinck  Phil CA
Iravani  Reza CA
Upal Ahsan CA
MakinoYoshinori JP
GuptaRobin GB