PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

160 Practical MATLAB® Applications for Engineers

The script fi le current_voltage is executed and the results are shown as follows:

>> current _ voltage

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

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The currents I1 I2 I3 I4 I5 I6 I7 and I8 (in amps) are given by:

1.0000

1.5000

0.5000

1.5000

4.5000

3.0000

3.0000

6.0000

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

The voltage Vab is:

45

volts

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

Example 2.17

For the circuit diagram shown in Figure 2.60

1. Write the three system mesh (loop) equations


2. Arrange the result of part 1 into a matrix equation


3. Using MATLAB, solve for the three loop currents (I 1 , I 2 , and I 3 )

FIGURE 2.60

Network of Example 2.17.

I 1

2 Ω

20 V

I 2 I 3

Loop # 1 Loop # 2 Loop # 3 10 V

15 V

+

−

+

−

+−

4 Ω

1 Ω 3 Ω 6 Ω

ANALYTICAL Solution

The loop equations are

Loop 1: 20 = 3 I 1 − 2 I 2 + 0 I 3

Loop 2: − 15 = − 2 I 1 + 9 I 2 − 4 I 3

Loop 3: − 10 = 0I 1 − 4 I 2 + 10 I 3

The resulting matrix equation is

320

29 4

0410

20

15

1

2

3











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