Page 106 - Numerical Analysis Using MATLAB and Excel

Exponential and Polar Forms of Phasors

5

-36.8699
or

x = 4; y = −3; [theta,r] = cart2pol(x,y), deg = theta*180/pi
theta =

-0.6435

r =
5

deg =
-36.8699
Check with the Simulink model of Figure 3.15:

Figure 3.15. Simulink model for Example 3.8 (d)

Example 3.9

Express the phasor 230°∠– in exponential and in rectangular forms.

Solution:

∠
j
–
We recall that 1– = j 2 . Since each rotates a vector by 90° counterclockwise, then 230° is
the same as 230°∠ rotated counterclockwise by 180° . Therefore,
∠
∠
)
∠
– 230° = 2 ( ∠ 30° + 180° = 2210° = 2 – 150°
The components of this phasor are shown in Figure 3.16.

Numerical Analysis Using MATLAB® and Excel®, Third Edition 3−19
Copyright © Orchard Publications