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function poweran(filename, pf_angle)
% Power analyser
%
% Analyse and plot the instantaneous, real, and reactive
% power of a waveform given by a tab-separated value
% (TSV) file.
%
% Required measurements to input:
% power factor angle (degree)
%
% The following column headers for the TSV are assumed:
% time, v1, v2, v3, i1, i2, i3
%
% Time measurements are assumed to be in milliseconds.
% All voltages and currents are assumed to be given
% in Volts and Amperes, respectively.
data = readtable(filename, FileType="text", Delimiter="\t");
L = length(data.time);
t = linspace(0, data.time(end), L);
p = data.v1(1:L) .* data.i1(1:L);
% Sum over a full period to get the RMS values.
n = length(data.time(data.time < 1e3/60));
vrms = sqrt(sum(data.v1(data.time < 1e3/60).^2)/n);
irms = sqrt(sum(data.i1(data.time < 1e3/60).^2)/n);
% These are constant in time so we extrapolate with two points
% to save compute time.
real_power = ones(2) * vrms * irms * cos(deg2rad(pf_angle));
reactive_power = ones(2) * vrms * irms * sin(deg2rad(pf_angle));
display(vrms);
display(irms);
figure(1);
subplot(3, 1, 1);
plot(t, p, "r", LineWidth=2);
title("Instantaneous Power versus Time");
xlabel("Time, $t$ (ms)", Interpreter="latex");
ylabel("Power, $p(t)$ (W)", Interpreter="latex");
subplot(3, 1, 2);
plot([0 data.time(end)], real_power, "g", LineWidth=2);
title("Real Power versus Time");
xlabel("Time, $t$ (ms)", Interpreter="latex");
ylabel("Real Power, $P$ (W)", Interpreter="latex");
subplot(3, 1, 3);
plot([0 data.time(end)], reactive_power, "b", LineWidth=2);
title("Reactive Power versus Time");
xlabel("Time, $t$ (ms)", Interpreter="latex");
ylabel("Reactive Power, $Q$ (VAR)", Interpreter="latex");
end
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