Systems Design, Fabrication, and Testing of a High‐Speed Miniature Motor for Cryogenic Cooler

Abstract

The long-term storage of liquid hydrogen for space missions is of considerable interest to NASA. To this end, the Reverse Turbo-Brayton Cryocooler (RTBC) is considerably lighter than conventional designs and a potentially viable and attractive solution for NASA's long-term Zero-Boil-off (ZBO) hydrogen storage system for future space missions. We present the systems design, fabrication, and performance evaluation of the Permanent Magnet Synchronous Motor (PMSM) powering a cryocooler capable of removing 20 W of heat at 18 K with a COP of 0.005 and driven by two 2-kW permanent magnet synchronous motors operating at 200 000 rpm and at room temperature and 77 K. Structural, thermal, and rotordynamic aspects of system design are considered.

Large electric machines for aircraft electric propulsion

“…The airgap winding is often made using Litz wire (a bundle of very small strands twisted together) to reduce the high‐frequency ac copper losses. In [55, 56], a 200 krpm HSP PMSM that utilises a Litz wire airgap winding is presented. The lower losses and higher electric loading help to improve the SP.…”

Forced convective mixing in a zero boil-off cryogenic storage tank

“…et al[23] presented the system design, fabrication, end performance evaluation of a Permanent Magnet…”