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EOS Emergency Power

This SatLab plot shows the power available to an EOS satellite in emergency mode. The SatLab script that generated this analysis is shown below.

Figure 1: EOS Emergency power analysis
Script - EOS Satellite in Emergency Mode
  1. % Demo: EOS satellite in emergency mode
  2. %
  3. % This demo simulates an EOS satellite in emergency
  4. % mode. The satellite is rotated about its y-axis
  5. % by 55 deg and is spinning about its x-axis with
  6. % a rate of 1 rpm
  7. %
  8.  
  9. removeAll;
  10. clearGraphic();
  11. setSimEpoch(2000,3,21,12,0,0);
  12. addEpoch('equinox',2000,3,21,12,0,0);
  13. noon   = 0;
  14. six_am = -90;
  15. addSatellite('EOS Sat',7171,0,98,six_am,0,0,'equinox');
  16.  
  17. %earthstation
  18. earth0 = "Frankfurt";
  19. addStation('Frankfurt', I_earth, 10, 50.05, 8.4, 0.1);
  20. dtime = 4;
  21. alphaleft = 55 *d2r;
  22. t = 0:dtime:2000*dtime;
  23. fleft0 = roty(alphaleft)*[0
  24.                            1
  25.                            0];
  26.  
  27. setSimTime(0);
  28. setSimStepSize(dtime);
  29.  
  30. %
  31. % Solar Panel: current(temperature, voltage) for a
  32. % reference flux of 1353
  33.  
  34. z_matrix =
  35. [   026.7527.2527.7528.2528.7529.2529.7530.2530.7531.25
  36.   10012.3912.2312.1412.1411.9510.6410.5110.3310.14  9.94
  37.    9012.6712.5912.5012.3912.2611.7611.6811.3611.4811.36
  38.    8012.7712.7312.6812.6312.5712.3112.2712.2212.1712.11
  39.    7012.7812.7612.7412.7112.6812.5512.5312.5112.4812.45
  40.    6012.7412.7312.7212.7112.6912.6312.6212.6112.6012.68
  41.    5012.6812.6812.6712.6712.6612.6312.6312.6212.6212.91
  42.    4012.6112.6112.6112.6112.6012.5912.5912.7912.8813.18
  43.    3012.5312.5312.5312.5312.5312.5312.5712.6312.7312.72
  44.    2012.4612.4512.4512.4512.4512.4512.4512.4512.6512.45
  45.    1012.3812.3812.3812.3812.3812.3812.3812.3812.5812.38
  46.     012.3012.3012.3012.3012.3012.3012.3012.3012.4012.30
  47.   -1012.2212.2212.2212.2212.2212.2212.2212.2212.2212.22
  48.   -2012.1412.1412.1412.1412.1412.1412.1412.1412.1412.14
  49.   -3012.0612.0612.0612.0612.0612.0612.0612.0612.0612.06
  50.   -4011.9811.9811.9811.9811.9811.9811.9811.9811.9811.98
  51.   -5011.7011.8411.9011.9011.9011.9011.9011.9011.9011.90
  52.   -6011.3211.6211.7211.8211.8211.8211.8211.8211.8211.82
  53.   -7011.1411.2411.4411.6411.7411.7411.7411.7411.7411.74
  54.   -8010.9510.9511.3511.4511.6511.6511.6511.6511.6511.65];
  55.  
  56. j         = 0;
  57. templeft  = 0;
  58. solarflux = 1420;
  59. alpha     = 0.65;
  60. epsilon   = 0.81;
  61. albedo    = 0.3;
  62. sigma     = 5.67e-8;
  63. capacity  = 660;
  64. qir       = 0;
  65.  
  66. num_of_strings = 36;
  67. eview = 0.045;
  68. dt    = 60;
  69. gamma = 0;
  70. reference_flux_si = 1353;
  71. voltage = 28;
  72. current = zeros(size(t));
  73.  
  74. for i=t,
  75.     j=j+1;
  76.    
  77.     stepSim;
  78.     [d,r,a,e,v] = PlanetPosition();
  79.     gamma = i/30*pi;
  80.     fleft = rotx(gamma) * fleft0;
  81.     theta = fleft` * unitvector(a(2),e(2));
  82.     theta = theta*v(2);
  83.     theta = max(0,theta);
  84.     templeft = templeft+((((theta*solarflux*alpha)
  85.                + (theta*solarflux*albedo*alpha*eview))
  86.                - (epsilon*(templeft^4)*sigma)+theta*qir)
  87.                * (dt/capacity));
  88.     current(j) = ((num_of_strings*theta)
  89.                   *table(z_matrix,(templeft-273.15),voltage)
  90.                   *((solarflux/reference_flux_si)/12));
  91. endfor
  92.  
  93. average = sum(current*voltage)/prod(size(t));
  94.  
  95. erase
  96. window('111');
  97. plot(t,current*voltage,
  98.      t,ones(size(t))*average, 'grid');
  99. title('6 a.m. Power in emergency mode')
  100. ylabel('P [Watt]');
  101. xlabel('t [sec]')