Smart Power Line and photonic de-icer concepts for transmission-line capacity and reliability improvement

This paper introduces the Smart Power Line (SPL) concept. This novel approach can be implemented on existing transmission lines comprising of single- or multiple-conductor bundles. It can also be applied to new, advanced line schemes. The SPL addresses three important needs: line de-icing, line impedance modulation and line monitoring.Line de-icing (LDI) can be activated prior to or during any severe climatic event, for concentrating the total power line current into one subconductor at a time and therefore de-icing by the Joule effect. Line impedance modulation (LIM) is another feature of the SPL by which line power flow and stability are also controlled by individually switching in and out subconductors of bundled-conductor lines, thereby modifying the net line impedance directly and dynamically. Line monitoring (LMO) provides real-time data related to electrical, mechanical or climatic events needed for line de-icing, power flow or stability control. By combining these three functions together, the SPL concept is expected to improve transmission-line reliability and transmission-line capacity. The power line reliability and life expectancy are increased by avoiding line and tower collapse due to ice deposits, hard rime or wet snow, reducing metal fatigue and avoiding failure due to galloping. The SPL concept can be applied to bundled-conductor transmission lines at any voltage level (HV and UHV).In addition to the SPL concept, new de-icing equipment, the so-called photonic de-icer, is also introduced in this paper. In order to ensure the mechanical robustness of the transmission line in the event of severe ice storms, past experience has shown that the switchgear must be maintained operational at all times. The photonic de-icer is operated at ground level and at ground potential to melt ice on substation apparatus or to keep the latter warm during icing events.