Page 108 - Numerical Analysis Using MATLAB and Excel

Exponential and Polar Forms of Phasors

Example 3.10

∠
∠
Multiply A = 12.58 74.3° by B = 7.22 – 118.7°
Solution:
Multiplication in polar form yields

)
∠
AB = ( 12.58 × 7.22 ∠ 74.3° + – ( [ 118.7° ] ) = 90.83 – 44.4°
and multiplication in exponential form yields

(
–
AB = ( 12.58e j74.3° ) ( 7.22e j – 118.7° ) = 90.83e j74.3° 118.7° ) = 90.83e j – 44.4°
Check with MATLAB:

r1=12.58; r2=7.22; deg1=74.3; deg2=−118.7; r=r1*r2, deg=deg1+deg2
r =

90.8276

deg =
-44.4000
*
Check with the Simulink model of Figure 3.18 :

Figure 3.18. Simulink model for Example 3.10

* It would certainly be a waste of time to use Simulink for such an application. It can be done faster with just
MATLAB. The intent here is to introduce relevant Simulink blocks for more complicated models.

Numerical Analysis Using MATLAB® and Excel®, Third Edition 3−21
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