Cyrogenic System Stability

Cryogenic components are being proposed for a ground-transportable radar (GTR) systems. Incorporating low-loss components into power-electronic based systems is a concern from the standpoint of system stability due to the inherent low resistance of the cryogenic components which may tend to destabilize the system due to reduced damping. The purpose of the work proposed herein is first to investigate the stability of this type of GTR system. This is to be accomplished by first defining a baseline GRT system configuration and then determining the parameters, and the variation thereof, in order to approximate the operating characteristics of the proposed cryogenic GTR. The overall goal, however, is to conduct a first-look into optimizing performance, weight, and cost of a GTR system in regard to system stability. Optimization studies will focus first on small-disturbance stability and then on large-excursion stability with a pulsed load present. During this research, a new and innovative means of eliminating negative- impedance instability, which has recently been shown to be effective on a noncryogenic power- electronic based system, will be considered as a means of reducing the weight requirements by decreasing the number and size of the system capacitors for a low-loss GTR system. The possible use of this stabilizer control in a pulsed-load environment has not been investigated. Moreover, the possible interaction of the various system controllers, including the stabilizer control, will be investigated with a focus on achieving optimum system performance through appropriate coordination or modification of the system controllers.