Universal Drive for Tactical Cryocoolers
B. Pilvelait, R. Kline-Schoder
Creare Inc., Hanover, NH
Superconducting Electronics (SCE) systems are becoming commonplace due to their substantial benefits in performance and cost when compared to traditional, semiconductor-based components. For example, HYPRES, Inc. is presently developing novel superconducting digital-RF technologies that enable highly efficient multi-carrier, broadband systems for military and commercial communications and other RF applications. To achieve widespread adoption of SCE systems, low- cost and rugged cryocoolers and associated drives are needed. In cooperation with HYPRES, Creare is developing a universal Tactical Cryocooler Drive (TCD) for Stirling and Pulse tube-class cryocoolers. TCD provides dual independent drives that can be customized for each application with software changes. In this paper the results of a comprehensive design study and brassboard demonstration are described. The electronics simultaneously and independently controls dual cryocooler compressors with input power up to 270 W and efficiencies as high as 96%. The technology is scalable to power levels of 1,500 W per channel. The electronics has been demonstrated the following attributes through brassboard tests: (1) a Pulse Width Modulation (PWM) control strategy, which results in minimal ripple currents, (2) a custom, programmable waveform generation method based on a Graphical User Interface (GUI), (3) thermal control was able to maintain temperature at 66 K in the presence of thermal loads up to 2.5 W, and (4) a control strategy that minimizes the exported vibration from the dual-compressor apparatus by independently controlling drive amplitude and phase relationships. This paper describes the results of these demonstrations and our plans for building and demonstrating a prototype with the form, fit, and function of the final product.