Design and Operation of a Cost-Effective Cooling Chamber for Testing Power Electronics at Cryogenic Temperatures

In recent decades, research in the field of cryogenic power electronics has gained increasing interest, as it promises advantages such as higher power density and higher efficiency. Particularly in the mobility sector, lower weight and smaller size are essential to advance electrification [1]. Another incentive and benefit of lower power losses is the reduction in operating costs. However, the study in [2] has shown that energetic profitability of low-temperature cooling is achieved, in particular, in applications where the necessary cooling for the power electronics is available for free and synergy effects can be realized within the overall system. Interesting areas of application are, therefore, in the field of aviation, where the cold ambient temperature of -55 ? is available, and in the mobility sector. Cryogenically stored fuels such as liquid hydrogen (LH2) or liquid natural gas (LNG) must be heated before they can be used, for example LH2 for application in a fuel cell, for which the power losses generated in a power electronic converter can be used perfectly. This saves energy for extra heaters and increases the efficiency of the power electronics [2]. One challenge when operating power electronics at temperatures below -40 ? is that most electronic components are not specified from the manufacturer for these temperatures. Therefore, a comprehensive characterization of all required electronic components for a deep temperature operation is essential, for which a suitable environment-a cryogenic cooling system-with variably adjustable ambient temperature is required.