Environmental Engineering Reference
In-Depth Information
The above relationships have simply been obtained by algebraically
adding, before taking their modules,
with
and
with
7.4 AN ALTERNATIVE FREQUENCY ANALYSIS
In this paragraph we describe a simple analytical procedure to calculate
the closed-loop harmonic distortion factors in the frequency domain, already
found in section 7.2.2 through an euristic demonstration, and used in this
chapter. Refer again to Fig. 7.5 and express the source signal as
Due to the nonlinear block in the direct path the output signal will include
harmonic components. Assume it is given by
where coefficients and have to be determined.
The error signal, is the difference of the source signal and the output
signal times the value of the feedback factor evaluated at the appropriate
frequency
