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

Abstract

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 ...

Quasi-neutral fluid models for current-carrying plasmas

“…This phenomenon is studied in relation with two physical applications: high-current diodes [30,34,45,54,57], and arcing on satellite solar generators [6,19,[25][26][27][28]38,39,50,51,56]. A series of works [13][14][15][16] have been realized to describe this process.…”

“…The scenarios for arc formation on satellite solar generators have been widely investigated [6,[25][26][27][28]38,50,51,56]. According to this scenario, the satellite charging in the earth environment plasma triggers a primary discharge between a cell interconnect and the dielectric which is used in the protective layer.…”

Power losses for solar arrays of a spacecraft in the Earth’s polar ionosphere and magnetosphere

“…9. Потенциалы ϕ W , измеренные на поверхности ИСЗ серии DMSP (F-6, F-7, F-13) в тени Земли в зависимости от концентрации положительных ионов в полярной ионосфере: крестики -данные F-6, косые крестики -F-7, точка -F-13, треугольник -данные [21,25], 1 -граничная кривая центрации ионов i n < 100 см -3 на поверхностях КА серии DMSP накапливаются отрицательные потенциалы −ϕ W ≥ 200 В, при которых возможно формирование электрических разрядов и пробоев [41,46].…”