Arc mitigation on high voltage solar arrays

Mong, Renee; Hastings, Daniel E.

doi:10.2514/6.1993-569

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(9) into integral and taking into account that n eo t 1 we obtain Am p 2kT e eV e 1=2 CU 1=2 (11) This relation between arc current pulse width and capacitance was obtained in a slightly different form in [15]. The dependence of pulse width on capacitance can be easily verified in the experiment.…”

Section: Dissociative Recombinationmentioning

confidence: 92%

“…The first model is based on the hypothesis that a thin insulating layer on the surface of a negatively charged conductor undergoes electrostatic breakdown when the electric field strength becomes high enough [9]. The second model takes into consideration the formation of a strong electric field in the area of the metal, dielectric, and plasma junctions [10][11][12]. The estimated average electric field strength in this case is usually a few hundred times below than is typically needed to initiate an arc.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Role of Water Vapor in Solar Array Arc Initiation: Dissociative Recombination Processes

Galofaro

Vayner

Degroot³

et al. 2006

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

Strong supporting evidence that adsorbed water vapor residing at the triple junction sites on a solar array is a leading contributing factor to arcing onset in conventional silicon photovoltaic arrays immersed in low Earth orbital plasmas is presented. It is suggested that an adsorbed water vapor layer becomes ionized by energetic electrons and that the discharge develops in the area of a triple junction. The fastest process to extinguish the discharge is the dissociative recombination of water molecular ions. Arc plasma spectroscopic data throughout the wavelength range 260-680 nm is obtained. The two most intensive silver lines in the UV spectrum (Ag I, 328 and 338 nm), an atomic silver line (Ag I, 358.6 nm), and two lines of singly ionized silver atoms (Ag II, 318.7 and 368.2 nm) are identified. Additionally, atomic line spectra Fe I (415.87 nm) and Ni I (480.7 nm) are found. More importantly, identification of several species that appear to validate a dissociative recombination process involving water vapor is also found. The observations involved are the OH molecular band (302-309 nm) and two intensive atomic lines (H-, 656.3 nm, and H-, 486 nm). The following species with molecular bands, CH (432 nm), SiH (387 nm), and SiN (472 nm) are also identified. Nomenclature A= molecular mass C = capacitance, F e = electron charge, C k = Boltzmann constant, ergs eV 1 I = current, A m p = proton mass, g N i = total number of metal ions N W = total number of adsorbed molecules n e = electron number density, cm 3 P = pixel number R = radius of sphere, cm R = recombination rate, s 1 cm 3 S = area, cm 2 T e = electron temperature, eV t = time, s U = bias voltage, V V e = electron velocity, cm s 1 = recombination constant, cm 3 s 1 q = electrical charge, C = wavelength, nm e = electron thermal speed, cm s 1 = surface density, cm 2 = cross section, cm 2 = pulse width, s

show abstract

Section: Dissociative Recombinationmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Role of Water Vapor in Solar Array Arc Initiation: Dissociative Recombination Processes

Galofaro

Vayner

Degroot³

et al. 2006

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

show abstract

“…The APEX orbit during this time was in a noneclipse orientation, and so the cells were always hot when biased, gathering a large number of data points at the high temperatures. Because arcing data were desired during eclipse times, positive biasing was resumed Oct. [24][25][26][27][28][29][30]1994, while the satellite remained in a sunlight-only orbit. Negative biasing was then continued from Oct. 31-Nov. 4, 1994 (days 94,304-94,308), when the APEX orbit contained portions of eclipse.…”

Section: Experiments Operationmentioning

confidence: 99%

Flight Data Analysis for the Photovoltaic Array Space Power Plus Diagnostics Experiment

Soldi¹,

Hastings²,

Hardy³

et al. 1997

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

As power demands continue to increase, spacecraft power systems are being designed to operate at higher voltages. When operating at high negative voltages, however, arcing may occur on the solar cells, generating electromagnetic interference and solar cell damage.Numerical and analyticmodels have been developed to simulate the arcing onset process, showing good agreement with experimental data. This simulation was used to predict arcing levels for the conventional geometry solar cells own on the Photovoltaic Array Space Power (PASP) Plus experiment. Both pre ight and post ight simulations showed good agreement with the ight data. The ight data were analyzed to examine correlations between arc rates and the various material, environmental, and operational parameters and to validate the theoretical model. Arcing levels were found to depend strongly on bias voltage, with the scalings suggested by the model proving to relate the arcing rates on the different modules accurately. Cell temperature was also veri ed as being a critical parameter, with high arcing rates seen at low temperatures. As expected from the model, there is a critical temperature, above which no arcing occurs. The ion ux was also seen to affect arc rates, as expected. Radiation ux to the arrays, however, did not affect arcing levels, although the data to support this conclusion are limited. Thus, the model was found to predict arcing levels for the cells under varying environmental and operational conditions and to allow data from one module to be accurately scaled to a module with different material and geometric parameters. This simulation could then be used to perform power system or solar cell design trade studies, with much less ground and ight testing needed for verication. NomenclatureA = Fowler-Nordheim coef cient (1:54 £ 10 ¡6 £ 10 4:52Á ¡1=2 W =Á W A=V 2 ) A array = solar array area, m 2 A cell = solar cell area, m 2 A wave = discharge wave area, m 2 B = Flower-Nordheim coef cient (6:53 £ 10 9 Á 1:5 W V =m) b n = coef cients in polynomial t to d i =d C diele = capacitance of dielectric, F/m 2 C front = capacitance of coverglass front surface, F C s = ion acoustic velocity, m/s C 1 , C 2 = coef cients to arc rate ts d = thickness of dielectric, m d i = distance of electron rst impact point from triple junction, m d 1 = thickness of coverglass, m d 2 = thickness of adhesive, m E d = neutral adsorbate binding energy, eV E max = electron incident energy for maximum secondary electron yield, eV E se = secondary electron energy, eV E se1 = electron incident energy for a secondary electron yield of unity, eV e = electron charge m e = electron mass, kg m i = ion mass, kg N cell = number of solar cells in array N n = number density of neutral particles adsorbed on dielectric side surface, m ¡2 N n0 = surface neutral density for monolayer coverage, m ¡2 n e = plasma number density, m ¡3 n na = ambient neutral density, m ¡3 n nc = critical desorbed neutral density for breakdown, m ¡3 Q ESD = effective electron stimulated desorption cross section, m ...

show abstract

“…It should be noted that th e rol e of electron impact desorption of water mo lecul es was thoroughly discussed almost ten yea rs ago [7,8], and the .…”

mentioning

confidence: 99%

The Neutral Gas Desorption and Breakdown on a Metal-Dielectric Junction Immersed in a Plasma

Vayner

Galofaro

Ferguson

et al. 2002

33rd Plasmadynamics and Lasers Conference

View full text Add to dashboard Cite

New results are presented of an ex perim enta l study and theoretica l analys is of arcing on metal-dielectri c j un ctions immersed in a low-density plasma. Two sampl es of conventional so lar arrays have been used to in vestigate the effects of arcing within a wide range of neutral gas pressures, ion currents, and electron number densiti es. All data (except video) were obta in ed in digita l form that all owed us to study the corre lation between extern al parameters (plasma density, addition al capacitance, bias vo ltage, etc) and arc ch aracteristi cs (arc rate, arc current pu lse width and amplitu de, gas species partial pressures, intensities of spectral li nes, and so on). Arc sites were determin ed by employ ing a video-camera, and it is shown that th e most probabl e sites fo r arc inception are tr ipl e-junctions, even though some arcs were initiated in gaps between ce lls. Th e effect of surface con diti oning (decrease of arc rate du e to outgass ing) was cl earl y demonstrated. Moreover, a co nsiderable in crease in arc rate due to absorption of molecules from atmosp heri c air has been confirm ed.The analys is of optical spectra (240-800 nm) revea ls intense narrow atomi c lin es (Ag, H) and wide molecul ar bands (OH, CH, SiH , SiN) that confi rm a com plicated mechani sm of arc pl asma generati on. The rate of pl asma contamination du e to arcing was measured by empl oy ing a mass-spectrom eter. These measurements provi ded quite reliabl e data for th e deve lopment of a theoretica l model of pl asma contamin ation. In conc lusion, th e arc threshold was in creased to above 350 Y (from 190 Y) by keeping a sample in vacuum (20 /-lTorr) for seven da ys . The res ults obta in ed are important for the understanding of the arc inception mechanism, which is absolute ly essential for progress toward th e des ign of highvo ltage so lar arrays fo r space app lication s.

show abstract

Arc mitigation on high voltage solar arrays

Cited by 4 publications

References 0 publications

Role of Water Vapor in Solar Array Arc Initiation: Dissociative Recombination Processes

Role of Water Vapor in Solar Array Arc Initiation: Dissociative Recombination Processes

Flight Data Analysis for the Photovoltaic Array Space Power Plus Diagnostics Experiment

The Neutral Gas Desorption and Breakdown on a Metal-Dielectric Junction Immersed in a Plasma

Contact Info

Product

Resources

About