Development of a DC Motor Drive for Extreme Cold Environments

Spacecraft electronic systems routinely experience extreme environmental conditions, including cryogenic temperatures. Radioisotope heating units (RHUs) are commonly used to keep the electronic systems at warmer temperatures; however, the RHUs continually produce heat, are expensive, and add complexity and weight to the spacecraft. Previous research efforts have shown several commercially available components, both active and passive, can perform well in cryogenic environments, thus allowing for lower weight and complexity of the electronic systems aboard spacecraft [1-7]. This paper details the cryogenic testing (down to -184degC) of commercially available component technologies commonly used in DC motor drives to determine which could provide feasible operation in an extreme cold environment. The performance of silicon carbide (SiC) diodes and transistors at cold temperatures was evaluated as well. The building and testing (down to -184degC) of a cryogenic 20 W full bridge power stage for motor drive applications was completed successfully; however, the performance of a motor controller resulted in component failure when subjected to an extended exposure time at the coldest test temperature (-184degC).