High Energy Cryogenic Varistors

High energy (>1kJ/cc) varistors operating at cryogenic temperatures (<77 degrees Kelvin) are being developed at Busek. Power generation, distribution and energy storage at cryogenic temperature is more efficient and requires less massive systems than the room temperature equivalents. These systems, as well as superconducting coils/magnets, require surge/discharge protection devices capable of operating at the same temperatures. Additionally, low voltage cryovaristors may be the enabling technology for protection of high temperature superconductors (HTS) which, when mature, will be used in all electrical systems. Continuous (DC) power dissipation of 2 kW/cc at room temperature was already demonstrated. Development of varistors with higher DC and pulse ratings is currently proceeding via the use of novel ingredients and material processing.