Heater Ramp Simulation

heater_ramp.m

%Tank Heater
clear;
clc;

nominal_heat = 200; %Watts
ramp_rate = 10.0;


Dt = .1;
heat = 0;
t = 0;
ii = 1;
T = [];
H = []; %heat output
P = []; %power input

on = 0;

start_time = 2;
stop_time = 90;
tmax = 200;

while t < tmax
  dt = Dt*rand(); %simulate random variation in timesteps

  %NASSP code is from here...
  ramp = 1-exp(-dt/ramp_rate);
  if(heat < nominal_heat && on)
    heat += (nominal_heat-heat)*ramp;
  else
    heat -= heat*ramp;
  endif
  %thermic(heat);
  %...to here

  if(on)
    P(ii) = nominal_heat;
  else
    P(ii) = 0;
  endif

  H(ii) = heat;

  %for testing
  if ((t > start_time) && (t<stop_time))
    on  = 1;
  elseif t >= stop_time
    on  = 0;
  endif

  t += dt;
  T(ii) = t;
  ii++;
end

plot(T,H,T,P)
grid on;
grid minor
axis ([0 tmax, 0 nominal_heat*1.1]);
xlabel("Time [s]");
ylabel("Power [W]");
legend("Heat Output", "Power Input")