PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

168 Practical MATLAB® Applications for Engineers

The script fi le analysis_exam is executed and the results are shown as follows and in

Figure 2.65.

>> analysis _ exam _ 1020

* * * R E S U L T S * * *

***************************

The network time constants are (in sec):

tau1 =

1

tau2 =

0.5000

The maximum currents are:

I1Max =

8.6466

I2Max =

5.7644

I3Max =

2.8822

The magnitude of the maximum voltage across L is:

VLMax =

-156.4762

******************************************

FIGURE 2.65

Transient plots of Example 2.20.

0

− 150

− 100

− 50

0

50

100

0

1

2

Current in amps

Voltage in volts

Current in amps

3

0

8

6

4

(^2) Current in amps
0
6
4
2
10
123
time in seconds
0123 45
time in seconds
45
012345 012345
Current i3(t) versus t
Current i1(t) versus t Current i2(t) versus t
Voltage vL(t) versus t
time in sec time in sec
Observe that the voltage across the inductor vL(t) at t = 2 s is vL(t = 2) = 156.4762 V when
the applied (source) voltage is V = 100 V. Observe also that at t = 2 s, I1max = 8.6466
A = I2max + I3max = 5.7644 A + 2.8822 A verifying KCL.