PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

(sharon) #1

Alternating Current Analysis 229


Note that

AVm t dt A dt A T

TT
sin()  0 ,
0

22

∫∫ (^0)
and
V t dt V t dt


V


dt

V


T


m

T
m

T

mm

22
0

2
0
22
0

1


2


1


2


2


22


∫∫sin ()  cos( )















TT

Then

V


T


AT


V


T


A


V


A


V


RMS
m

mm







1


2


2 2


2

2

2

2
2

2

















Note that

V
m VVmRMSAC
2

∗0 707. 


Then

VAVRMS^22 RMS AC ,()forvtAVtmsin()

If

v( )tAVmm11 2 2sin( tV) sin( t V)mnnsin( t)

then

VA


V


RMS mk AV
k

n
RMS

n



2
2

1

22

(^21)
∑∑k
k
for k AC sources and one DC source (A).
R.3.12 The power dissipated by a resistor R, having a current i(t) over an interval of time
[t 1 , t 2 ], is given by


P


tt

Ri t dt
t

t



1


21

2
1

2
∫ ()
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