A NUMERICAL METHOD OF HARMONIC ANALYSIS 689
L
Figure 73.7
- For the waveform of current shown in
Fig. 73.7(b) state why only a d.c. compo-
nent and even cosine terms will appear in the
Fourier series and determine the series, using
π/6 rad intervals, up to and including the sixth
harmonic.
[
I= 4. 00 − 4 .67 cos 2θ+ 1 .00 cos 4θ
− 0 .66 cos 6θ
]
- Determine the Fourier series as far as the third
harmonic to represent the periodic functiony
given by the waveform in Fig. 73.8. Take 12
intervals when analysing the waveform.
− 20
− 40
− 60
− 80
− 100
20
40
60
80
100
y
− 90 ° 0 90 ° 180 ° 270 ° 360 ° θ°
Figure 73.8
⎡
⎣
y= 1. 83 − 27 .77 cosθ+ 83 .74 sinθ
− 0 .75 cos 2θ− 1 .59 sin 2θ
+ 16 .00 cos 3θ+ 11 .00 sin 3θ
⎤
⎦
