Magitude from a three phase signal
5 views (last 30 days)
Show older comments
Md. Nazrul Islam Siddique
on 21 Feb 2023
Commented: Md. Nazrul Islam Siddique
on 11 Apr 2023
How to find the angle and magnitude of a three phase signal? The signal has two cycles. I want to find the angle and magntude for each cycle. I want to use signal processing technique.
0 Comments
Accepted Answer
Sulaymon Eshkabilov
on 22 Feb 2023
Here is how to perform FFT and compute the phase angle values in rad:
data = readmatrix('D_Sample.xlsx'); % Sample data import
t = data(:,1); % Column 1 is time data
N = numel(t); % Number of data points
Ts=mean(diff(t)); % Data Sampling time, [s]
Fs=1/Ts; % Data Sampling frequency, [Hz]
% Measured data has some noise that is cleaned using low-pass filter
xf =lowpass(data(:,2), 175,Fs) ;
yf =lowpass(data(:,2), 175,Fs) ;
zf =lowpass(data(:,2), 175,Fs) ;
Nfft=2^nextpow2(N);
x=fft(xf,Nfft)/N;
y=fft(yf,Nfft)/N;
z=fft(zf,Nfft)/N;
f=Fs/2*linspace(0,1,Nfft/2+1);
figure(2)
plot(f,2*abs(y(1:Nfft/2+1)));
grid on
title('Single-Sided Amplitude Spectrum of acceleration: a_x(t)');
xlabel('Frequency(Hz)');
ylabel('|a_x(f)|');
phasex=angle(x);
phasey=angle(y);
phasez=angle(z);
figure(2)
subplot(2,1,1)
plot(f,2*abs(x(1:Nfft/2+1)));
grid on
title('Single-Sided Spectrum of a_x(t)');
ylabel('|a_x(f)|');
subplot(2,1,2)
plot(f,phasex(1:Nfft/2+1))
grid on
xlabel('Frequency(Hz)');
ylabel('Phase of a_x(rad)')
figure(3)
subplot(2,1,1)
plot(f,2*abs(y(1:Nfft/2+1)));
grid on
title('Single-Sided Spectrum of a_y(t)');
ylabel('|a_y(f)|');
subplot(2,1,2)
plot(f,phasey(1:Nfft/2+1))
grid on
xlabel('Frequency(Hz)');
ylabel('Phase of a_y(rad)')
figure(4)
subplot(2,1,1)
plot(f,2*abs(z(1:Nfft/2+1)));
grid on
title('Single-Sided Spectrum of a_z(t)');
ylabel('|a_z(f)|');
subplot(2,1,2)
plot(f,phasez(1:Nfft/2+1))
grid on
xlabel('Frequency(Hz)');
ylabel('Phase of a_z(rad)')
More Answers (1)
Sulaymon Eshkabilov
on 22 Feb 2023
Simulink -> Simscape toolbox, there is a block to compute magnitude and angle calculation:
See Also
Categories
Find more on Spectral Measurements in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!