PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

Alternating Current Analysis 297

Example 3.17

The objective of this example is to verify the maximum power transfer theorem, when

the load resistance varies over a given range.

Repeat Example 3.16 for the case where the load impedance is ZL = RL + jXL, where

XL = j30, whereas RL varies over the range 1 ≤ RL ≤ 100 Ω in steps of 1 Ω, as indicated

in Figure 3.76, with the Thevenin’s equivalent circuit given by VTH = 5 ∠0° V and ZTH =

10 − j50 (Ω).

Let us call this new fi le max_power_AC_RL.

0 50 100 150

0.08

0.085

0.09

0.095

0.1

0.105

0.11

0.115

0.12

0.125

XL (Ohms)

Power deliver to

ZL

(Watts)

Power ZL versus XL, for 0 <XL< 100

XL = 50j Ohms

FIGURE 3.75

Plot of ZL versus XL of Example 3.16.

ZTH = 10 − j 50 Ω

ZL = RL + j XL Ω

VTH = 5 0 ° V

RL = 0:1:100 Ω

XL = j30 Ω

FIGURE 3.76

Network of Example 3.17.