Page 348 - Solutions Manual to accompany Electric Machinery Fundamentals
P. 348
(b) The output spectrum of this PWM modulator is shown below. There are two plots here, one
showing the entire spectrum, and the other one showing the close-in frequencies (those under 1000 Hz),
which will have the most effect on machinery. Note that there is a sharp peak at 50 Hz, which is there
desired frequency, but there are also strong contaminating signals at about 850 Hz and 950 Hz. If
necessary, these components could be filtered out using a low-pass filter.
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