Ion-Flow Field Calculations of AC/DC Hybrid Transmission Lines

ISSN:0885-8977ISSN:1937-420

Novel Method for Predicting Limit Performance of Bus-Transfer Switching by Disconnectors

ISSN:0885-8977ISSN:1937-420

Theoretical Investigation of HVDC Disc Spacers Charging in SF6 Gas Insulated Systems

ISSN:1070-9878ISSN:1558-413

Improving GIS Disconnectors for Future HVDC Applications

The use of standard HVac disconnectors for bus-transfer switching in future HVdc gas insulated switchgear (GIS) has been demonstrated successfully in past research through simulation and testing. Prolonged arcing times through reignitions caused by high frequency harmonics as well as the proposed extension of GIS disconnector switching cases, however, create an HVdc-specific demand for more advanced disconnector concepts capable of withstanding higher switching stresses and increased recovery voltages. A spring-loaded disconnector designed for use in HVac mixed technology switchgear (MTS) was found to shorten the time to first current zero through an accelerated increase of the arcing voltage compared to standard disconnectors. Despite its increased switching performance, the reignition characteristics of this fast-acting disconnector were found to largely follow the previously established extinction criterion, which enables further simulation of similar technologies for HVdc applications. To additionally combat the issue of contamination of HVdc GIS by electrode erosion products, a prototype disconnector was improved using permanent magnets to evoke arc rotation. Erosion tests in air have shown an effective reduction of electrode erosion for long arcing times at currents typical for disconnector switching while bus-transfer tests revealed promising enhancements of the reignition behavior.ISSN:0885-8977ISSN:1937-420

The LHCb Silicon Tracker

Wide pitch silicon micro-strip detectors will be used in both the LHCb Inner Tracker and the Trigger Tracker. In total an area of 12 m$^2$ will covered with silicon using ladders of up to 33 cm in length. The design of both detectors and corresponding test beam results are presented

The LHCb Silicon Tracker

LHCb is one of the experiments for the Large Hadron Collider at CERN, dedicated to B-physics and CP-violation measurements. To fully exploit the physics potential, a good tracking performance with high effciency in a high particle density environment close to the beam pipe is required. Silicon strip detectors with large readout pitch and long strips will be used for the LHCb Silicon Tracker. The design and test beam results are presented here