PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

Alternating Current Analysis 307

subplot(2,2,3)

Pl = iamps*Vl;

ezplot(Pl)

title(‘pl(t) vs t’)

xlabel(‘ time ‘)

ylabel(‘power (watts)’)

grid on

subplot(2,2,4)

Pc=iamps*Vc;

ezplot(Pc)

title(‘pc(t) vs. t’)

xlabel(‘ time ‘)

ylabel(‘power (watts)’)

grid on

disp(‘^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^’)

disp(‘ time domain results ’)

disp(‘^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^’)

disp(‘The current i(t) (in amps) is given by: ‘), pretty(iamps)

disp(‘The voltage drop across R=1000 Ohms (in volts) is:’),pretty(Vr)

disp(‘The voltage drop across L=30 mH (in volts) is : ‘), pretty(Vl)

disp(‘The voltage drop across C=0.5 microF (in volts) is :’),pretty(Vc)

disp(‘The voltage drop across the RL (in volts) is :’),pretty(Vlr)

disp(‘The voltage drop across the CR (in volts) is : ‘),pretty(Vcr)

disp(‘The power _ R(t) (in watts) is :’),pretty(Pr)

fprintf(‘The power _ L(t) (in watts) is :’),pretty(Pl)

fprintf(‘The power _ C(t) (in watts is :’),pretty(Pc)

disp(‘^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^’)

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

(Figures 3.85 through 3.87):

>> sym _ analysis _ RLC

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

time domain results

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The current i(t) (in amps) is given by:

3 2

t + t - 12 t

The voltage drop across R=1000 Ohms (in volts) is:

3 2

1000 t + 1000 t - 12000 t

The voltage drop across L = 30 mH (in volts) is:

2

9/100 t + 3/50 t - 9/25

The voltage drop across C=0.5 microF (in volts) is:

4722366482869645 4 4722366482869645 3

-------------- t + --------------- t

37778931862957161709568 28334198897217871282176

14167099448608935 2

• ------------- --- t
  4722366482869645213696