Slip Ring Test Assembly With Increased Breakdown Voltage Limit for High-Voltage Bus Satellites

In this article, a setup including a passive gas breakdown mitigation technique for satellite slip ring assemblies (SRAs) is introduced and tested. The setup features a central conducting ring, separated from two external conducting limiting discs (LDs) by insulating rings. The characteristic breakdown curves are measured as a function of the surrounding pressure by biasing the central ring and setting the LDs at a variable voltage. The minimum breakdown voltage is increased from ~420 to ~860 V by biasing the LDs at one half of the voltage applied to the central ring. This solution is further applied on a test-SRA that includes the main features of a standard cylindrical SRA: a stack of conducting rings on which conducting brushes slip to ensure the electrical contact between moving components. The minimum of the breakdown curve is raised from ~400 V for the grounded LDs to ~600 V for the passively biased LDs. This result confirms the possibility to improve SRA protection for the entire pressure range encountered by a satellite during its operational life, from atmospheric pressure to in-orbit high-vacuum, meeting the requirements for the next generation of satellites.