High Efficiency Compact High Voltage Vector Inversion Generators

Roberts

2009 IEEE Pulsed Power Conference

2009

Self Cite

VIGs consist of two parallel plate transmission lines, wound on a mandrel and sharing a common conductor. They are a compact electrostatic energy storage device that can convert the stored energy into a traveling RF wave in a one component-one step process. In this paper, basic design equations that allow determination of the VIG erection time, the amount of energy stored in the unit, the amount of energy available at the output of the device and the restrictions on the value of the load impedance necessary for efficient energy transfer are discussed. We describe a method for determining the maximum current, I, and dI/dt that the two switches, low voltage input and high voltage output switch to the load, will see and the constraints imposed on the unit by these parameters. While the above parameters can be uniquely specified, great care must be taken in materials selection, precision winding technique, and insulation scheme to realize a unit that performs to its full potential. The limits on VIG technology as imposed by fundamental processes are discussed.

Section: E 5 -Corona Lossesmentioning

confidence: 99%

“…In our laboratory, we have been researching and developing Vector Inversion Generators, (VIG) for several years and have reported our progress extensively in the IEEE Pulsed Power Conferences (1,2,3). VIG's are deceptively simple.…”

Section: Introductionmentioning

confidence: 99%

Limits and failure modes in high voltage Vector Inversion Generators

Roberts

2009 IEEE Pulsed Power Conference

2009

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“…The power train for the device consists of a unique Ferroelectric Generator, FEG [1], a Vector Inversion Generator, VIG, configured as an oscillator [2,3], and an antenna to radiate the electromagnetic pulse. In order to improve the efficiency of energy transfer, we investigated resonant transfer from the FEG to the VIG.…”

Section: Introductionmentioning

confidence: 99%

Ultra-compact high efficiency multi-kilovolt pulsed power source

Roberts

2009 IEEE Pulsed Power Conference

2009

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Single shot, high power, high energy pulsed electrical sources have been investigated over the years. Research has encompassed high energy/high power devices such as magnetic flux compression generators (MCG), as well as high power but lower energy devices like Ferroelectric generators (FEG) and ferromagnetic generators (FMG). In this paper, we will discuss recent experiments aimed at producing a pulsed electrical system consisting of a FEG, resonant energy transfer element, high speed switching, a Vector Inversion Generator (VIG) configurable as an oscillator, and a means to combine them into an efficient system that delivers maximum energy to a load at voltages in excess of 100 kV. In its final embodiment, the pulse generator will be on the order of 1.5 inches in diameter and approximately 8 inches long and capable of delivering a fast high voltage pulse (~ 9ns rise time, 200 kV) at energy levels of "joules" to the load. In this paper, we will describe recent experiments to develop resonant energy transfer from the FEG to the VIG at high efficiency, the development of explosive/dielectric switching at kilovolt levels, and the explosive testing of prototype FEG/VIG configurations that constitute laboratory prototypes sufficient for modeling and simulation. In addition preliminary data showing high frequency oscillation for the FEG/VIG configured as an oscillator will be presented and analyzed in terms of possible antenna configurations and breakdown issues.

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mentioning

confidence: 99%

High Voltage Solid State Switched Vector Inversion Generator

Hanlon

2007 IEEE Pulsed Power Plasma Science Conference

et al. 2007

Self Cite

A Vector Inversion Generator, VIG, consists of two parallel plate transmission lines, sharing a common conductor that have been wound on a mandrel [1,2]. These units can be made highly efficient and are capable of developing high transient voltages in a time that is determined by the two way transit time for an electromagnetic wave to propagate up the "active" line. Heretofore, the active line in a VIG device was switched using a spark gap because of the extremely high dl/dt and large values of current, I. Spark gap switches have limited life due to electrode erosion, are difficult to trigger with precision and have limited pulse repetition rate. Further, spark switches are usually pressurized to increase operating voltage and to present an inert gas to the electrodes in the switch. By contrast, solid state switches have none of the undesirable characteristics of spark switches and gas plumbing but are limited in dl/dt, I and standoff voltage. In this paper, we will describe the results of our efforts to produce a solid state, precision switched, VIG for applications at high repetition rate and at modest energies. We will present VIG design methodology that determines the maximum value of both I and dl/dt that a switch will see as a function of line length and line impedance. In order to test our methodology, we purchased a solid state switch available from Applied Pulsed Power, Inc. This switch is capable of dl/dt on the order of 30 kA/ ts, peak operating voltage of 4.7 kV, and a peak repetitive current of 10 kA. Test data at voltages greater than 1 kV at a repetition rate up to 500 Hz will be presented. At these voltages, the VIG erected to greater than 60 kV. Due to controller and reverse diode issues, we conducted limited testing at higher voltages producing VIG erected voltages on the order of 100 kV. From these tests, we designed a switch for custom fabrication by Applied Pulsed Power. The switch is to be capable of peak repetitive currents greater than 30 kA, with dl/dt greater than 100 kA/ps. Performance and characterization of this switch will be presented and discussed in terms of VIG design constraints.