A computational study of the thermal performance of a 69 kV solid state current limiter submerged in FR3 dielectric coolant

This paper presents the results of thermal modeling of a unique 69 kV 3000A Solid State Fault Current Limiter (SSFCL) developed by Silicon Power of Malvern, PA with support of EPRI. The development of the Solid State Fault Current Limiter is expected to modernize power distribution systems through the use of small-scale solid-state power devices. The use of this new design is expected to increase reliability and functionality while reducing footprint. However, as the footprint is reduced, the heat flux for the system is increased, leading to the significant possibility of device failure due to thermal excursions if the heat load is not properly managed. The high heat loading requires the use of aggressive thermal management in the form of liquid cooling of the electronics. This system features 288 kW of waste heat in the three phase system. The system is submerged in FR3 dielectric coolant and the desired thermal management system is liquid natural convection within the tank and shed to the ambient through an external finned array system. This project explores the feasibility of this system design.