HV design of vacuum-insulated power supplies for space applications

Gollor, Matthias; Rogalla, K.

doi:10.1109/14.231550

Cited by 31 publications

(4 citation statements)

References 27 publications

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“…Spacecraft DC power supplies are designed to use voltages of ~5 kV to power analyzers, spectroscopes, and cameras, and can be even higher than 15 kV for spaceborne radar systems making ground observations [33]. Also, problems may arise when outdoor transmission lines carrying power at several hundred kilovolts crossing forested and agricultural areas [34,35].…”

Section: Introductionmentioning

confidence: 99%

Effect of AC electric field on flame spread in electrical wire: Variation in polyethylene insulation thickness and di-electrophoresis phenomenon

Park

Lim

Suk

et al. 2019

Combustion and Flame

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The effect of AC electric field on flame spread over polyethylene (PE)-insulated electrical wire was experimentally investigated by varying the applied AC voltage (VAC) and frequency (fAC) with special attention to the effect of the thickness of the PE insulation material (Tins). The diameter of the Ni-Cr wire was 0.5 mm and Tins was 0.15, 0.3, and 0.5 mm, yielding outer diameters (Dout) of 0.8, 1.1, and 1.5 mm, respectively. For the baseline cases with no electric field, the flame spread rate (FSR) (flame size) decreased (increased) with insulation thickness. Both FSR and flame size were appreciably influenced by applied AC electric fields. The FSR behaviors under applied electric fields could be classified into three sub-regimes as AC frequency increased: regime I exhibited a decreasing FSR as AC frequency increased, regime II exhibited an increasing FSR, and regime III again exhibited a decreasing FSR. Molten PE dripped from the wire (resulting in mass loss); exhibited di-electrophoresis (some molten PE moved from the main molten zone toward the burnt wire, forming globules in the process); and developed electrosprays (ejection of small droplets from the molten PE surface). For Dout = 0.8 mm, the FSR behavior was similar to that of the flame width, such that the behavior could be explained by the thermal balance mechanism. When a low voltage and high frequency were applied to wires with Dout = 1.1 and 1.5 mm, molten PE droplets detached and moved to the burnt wires continuously (although sometimes intermittently) from the main body of molten PE; the FSR behavior thus deviated from that of regime I. Droplet detachment was attributable to a di-electrophoresis. The distance moved correlated well with the difference in electric field intensities of burnt and unburned wires. Appreciable dripping of molten PE occurred at high voltages and moderate frequencies in regime II. When the frequency was excessive, flame extinction occurred via two routes: appreciable reduction of flame size when Dout = 0.8 mm in regime I and appreciable fuel mass loss via dripping of molten PE during flame spread when Dout = 0.8 and 1.1 mm in regime III. These extinction frequencies correlated well with VAC/Dout. When high voltage and frequency were applied in the Dout = 1.5 mm case, droplets detached and moved to the burnt wire via di-electrophoresis; subsequently a series of fine droplets ejected from the surface via electrospraying, while the molten PE region grew and subsequently dripped. In such cases, flame extinction did not occur because di-electrophoresis increased the flame width and thereby the FSR over the experimental ranges of VAC and fAC.

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Section: Introductionmentioning

confidence: 99%

Effect of AC electric field on flame spread in electrical wire: Variation in polyethylene insulation thickness and di-electrophoresis phenomenon

Park

Lim

Suk

et al. 2019

Combustion and Flame

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“…If HV equipment were to be switched on during this intermediate period, critical pressures caused by spacecraft venting and outgassing would certainly cause problems related to PD. When well known design rules such as the selection of low outgassing materials, increased insulation thickness, use of defect-free dielectric materials and, finally, worst case analysis of electric field stress in the HV devices [2], [3] PD phenomena can often be avoided or ignored.…”

Section: Introductionmentioning

confidence: 99%

Partial discharge testing of solder fillets on PCBs in a partial vacuum: new experimental results

Capineri

Dainelli

Materassi

et al. 2003

IEEE Trans. Electron. Packag. Manufact.

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This work investigates the influence on the partial discharge (PD) onset due to the geometry of solder fillets of aerospace and spacecraft component assemblies operating in vacuum and at high voltages. An automatic measuring system has been developed and calibrated to detect PD signals in vacuum (proportional to the apparent charge) which are recorded and displayed in terms of amplitude and temporal distributions. The experimental part of the project is aimed at investigating the influence of the geometry of solder fillets (produced according to the European space industry standard, ECSS-Q-70-08), on the occurrence of PD activity. Stranded terminals of high voltage cables were soldered to circular copper pads on FR4 fiberglass epoxy printed circuit board (PCB). Various copper electrode configurations have been produced and, prior to the test program, they were characterized for dimensional, electrical and optical properties. Two types of solder fillet geometries have been realized for each electrode configuration: round joints with an abundance of solder and sharp pointed joints made with minimal solder. The minimum distance between electrodes for all samples is nominally 5 mm. Paschen-like curves were established from measurements performed where the product of pressure x distance lies in the range of 2 mbar mm-50 mbar mm. Corona inception voltage (CIV) and corona extinction voltage (CEV) values were recorded at different values of pressure x distance. Stable glow discharge triggering voltage and current were also measured. The experimental results indicated that the PD activity for the sharp pointed pads and sharp pointed joints is greater than the other cases, but no significant differences (less than 50 V) of the values of CIV and CEV have been found.Index Terms-High voltage systems, partial discharges, printed circuit board, solder fillets.

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“…Indeed, 3D additive manufacturing methods allow to build a full structure in just one metallic piece, avoiding the use of connections or welds that could cause problems or deformations in the final response, as well as increasing the fabrication process speed. In addition, it avoids the use of dielectric materials in the structure, preventing problems such as intrinsic losses in these materials and the outgassing phenomenon [8] that dielectrics may suffer when they are used in space.…”

Section: Introductionmentioning

confidence: 99%

Methodology for Improving Scanning Performance Loading an Array Element with a 3D All-Metal WAIM

et al. 2022

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All-metal 3D printing technologies are allowing the conception of new structures for different applications. This publication explores the potential of employing for the first time an all-metal 3D unit-cell topology to perform wide-angle impedance matching layers. A new equivalent circuit is derived for the oblique incidence, providing a good estimation of the cell response for the scanning range (θ=[0°,55°]) in the main scanning planes for a linearly polarized radiated field. This analytical model is later used to develop a wide-angle impedance matching design methodology for a generic antenna. This methodology is tested in practice to match a phased array made of metallic horns at 18 GHz. An improvement of 5 dB is obtained in the simulations for angles θ>35° for the H-plane.

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HV design of vacuum-insulated power supplies for space applications

Cited by 31 publications

References 27 publications

Effect of AC electric field on flame spread in electrical wire: Variation in polyethylene insulation thickness and di-electrophoresis phenomenon

Effect of AC electric field on flame spread in electrical wire: Variation in polyethylene insulation thickness and di-electrophoresis phenomenon

Partial discharge testing of solder fillets on PCBs in a partial vacuum: new experimental results

Methodology for Improving Scanning Performance Loading an Array Element with a 3D All-Metal WAIM

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