A high-current, IGBT-based static switch for energy extraction in superconducting power circuits: Concept, design and production of a 30 kA monopolar and a 1 kA bipolar fast opening switches

The steadily increasing demand from the particle physics community for higher beam energies and higher integrated beam luminosity has reinforced the necessity for new accelerator equipment, frequently breaking with conventional technologies. One of the fields where new and innovative engineering is required and where interesting developments are ongoing, is the domain of fast switching of high DC currents, such as it is required for rapid and safe extraction of large quantities of energy stored in superconducting magnet circuits. The 30 kA opening switch, developed at CERN within the International High-Luminosity Large Hadron Collider project (HL-LHC), is an example of the innovative engineering required to satisfy the demands related to circuit protection. The paper presents the integration into an IGBT-based static DC switch of a variety of different inspired design principles, such as a triple-busbar layout for optimized circuit symmetry, the extensive use of laminated, water-cooled busbars and an optimized capacitive compensation of the parasitic inductances as well as a complete analysis of the thermal budget management of the individual IGBT modules. The paper will also briefly present the design of a compact modular, bipolar and redundant 1 kA IGBT-based switch assembly which features an all-laminated busbar concept.