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THz impulse communications is a new system concept based on an imaging radar that we have been developing for biomedical imaging applications the past ten years. Its hybrid architecture combines the high-peak-power and spread-spectrum of photoconductive-switch transmitters with the high-responsivity and broad-bandwidth (RF and video) of Schottky-rectifier receivers. The data is impressed by simple...
In combination with high temperature superconductive (HTS) equipment (e.g. current limiters) or in HTS subnets, which constitute a possible option for increasing the overall efficiency of electrical power distribution systems, only vacuum interrupters can be used directly in the liquid nitrogen environment. This would, however, be desirable for economic reasons. Circuit breakers and switches, respectively,...
The National Ignition Facility (NIF) is a 192-beam inertial confinement fusion machine that has been fully operational since May 2009, with more limited operation as far back as 2002. The Power Conditioning System (PCS) supports the NIF mission by driving 7680 flashlamps that pump laser slabs in the main and power amplifiers of the infrared section of the laser. On a typical target shot PCS stores...
Future development of electrical distribution and transmission technologies is driving the development of direct current (DC) circuit breakers (CB). The absence of a natural current zero, the required short interruption time and the absorption of energy during every switching process are some of the challenges for these breakers. One possible DC CB concept is to create an "artificial" current...
Vacuum interrupters (VI's) are the primary switching technology for medium voltage (1–52kV) electrical power systems. The extensive field service of VI's is now raising interest in determining the end of life for these devices, with the primary concern being the loss of vacuum. The manufacturing method of the VI's can affect the calculated long-term life. In particular, there are three main design...
Vacuum interrupters on medium voltage power systems need to interrupt short-circuit currents over a wide range of arc times. Synthetic testing allows the careful study of the interruption performance over arc times ranging from 0 to 13.3ms for a 50Hz system. Comparing the interruption performance as a function of arc time observed in single- and three-phase direct testing and single-phase synthetic...
This paper applies a general computational technique for optimal control of switched-mode hybrid systems, recently developed by the authors, to voltage-regulation problems in a step-down DC-DC converter. Unlike existing techniques that are based on model-predictive control and a specific algebraic structure of the problem, the algorithms presented here are based on gradient descent with Armijo step...
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