Folks,
I need help.
I am an engineer working on an oil project and I am doing studies in harmonic distortion on a power system. We have got some big threephase heater banks with phase controlled thyristors. I have been searching the internet for information on the spectrum of harmoic currents vs. firing angle, or, failing that, maximum values of harmonic currents over the whole range of firing angles. I have drawn a blank. So I have gone back to first principles and started doing some sums based on Fourier analysis. But it has been about 35 years since I did this sort of calculus and I feel a bit out of my depth.
I have attached two documents: one summarising the maths and the other a spreadsheet cacluating the harmonics. I would like some verification that the methodology is ok.
regards
David Bamber
I need help.
I am an engineer working on an oil project and I am doing studies in harmonic distortion on a power system. We have got some big threephase heater banks with phase controlled thyristors. I have been searching the internet for information on the spectrum of harmoic currents vs. firing angle, or, failing that, maximum values of harmonic currents over the whole range of firing angles. I have drawn a blank. So I have gone back to first principles and started doing some sums based on Fourier analysis. But it has been about 35 years since I did this sort of calculus and I feel a bit out of my depth.
I have attached two documents: one summarising the maths and the other a spreadsheet cacluating the harmonics. I would like some verification that the methodology is ok.
regards
David Bamber
Attachments

109.5 KB Views: 102