See attached Worksheet. Explanation also required as I am trying to solve these by myself also.© BrainMass Inc. brainmass.com October 25, 2018, 9:50 am ad1c9bdddf
From a set of initial conditions such as given angular frequencies and damping constants second order responses are derived using Excel and paperwork theory. Further a periodic waveform is defined in the time domain and its Fourier series components are derived using Fourier series theory. An Excel spreadsheet is used as a modelling toll to derive constants
Fourier analysis using Excel
The supply current was sampled 1024 times over a very short time interval. The data so obtained is given in column B of the accompanying Excel worksheet (see attached).
This worksheet has been set up to give a graph showing the spectral components of the data.
i) Obtain the Fourier Transform for the data using the Fourier Analysis tool of Excel. The transformed data should commence in cell D2.
ii) Identify the principal frequencies in the current waveform.
iii) Estimate the total harmonic distortion [THD] present in the current waveform using the formula:
(See attached file for equation)
Where I1 is the r.m.s. value of the fundamental current, In the r.m.s value of the nth harmonic and n(max) is the number of the highest measurable or significant harmonic.
[Note the vertical axis of the spectrum graph is scaled in (current)^2.]
iv) Attempt to synthesise the shape of the original waveform from its principal harmonics [e.g. sketch the waveforms of the harmonics on the same time axis and add them together].
Q4. Sketch, on a set of common axes, waveforms to represent the transient response of circuits having transfer functions with the following parameters:
(see attached file for more information)