Phase angle measurement

[etfpg]

Hi!

Is it possible to measure phase angle in Multisim? I want to measure phase angle of current through capacitor C1:

I got by hand ic1(t)=0.117*sqrt(2)*sin(2*pi*50*t-178.040deg) 

Thanks in advance.

[etfpg]

Solved...

[Tien_P]

Hi,

Run the Single Frequency AC Analysis, set your frequency to 50Hz and set the "Complex number format" to Magnitude/Phase.

[etfpg]

Hi!

I did it and here are phase angles for 4 nodes in our circuit:

It matches with result I got by hand. However, for some reason phase of current through capacitor C1 doesn't match with my result.

Multisim measures 1.95947 degrees. Just to mention that I edited "AC analysis magnitude" of voltage source (12sqrt(2)=16.9705627 instead of default 1). Current source shouldn't be modified.

[etfpg]

It doesn't calculate phase angle correct. Here is complex current IC1:

IC1=-0.1174-0.0040195j. Phase angle of this current is atan(-0.0040195/(-0.1174))-pi=-3.1073rad=-178.040deg. Multisim calculates only atan(-0.0040195/(-0.1174))=1.959deg.

[etfpg]

Any comment? 

[Tien_P]

This is what I got.

Multisim file is attached.  

The value is the same however, the real part shows positive in Multisim but your calculation shows negative. I have not gone through the calculation myself.

[etfpg]

I got same result in Multisim as you. I will check my calculation one more time.

[etfpg]

Here is system of equations for this circuit (Matlab code):

R1=100;
R2=200;
R3=300;
L1=100*10^(-3);
L2=2*10^(-3);
C1=220*10^(-6);
C2=470*10^(-6);
E=12;
w=2*pi*50;
Xl1=w*L1;
Xl2=w*L2;
Xc1=1/(w*C1);
Xc2=1/(w*C2);

I=1/sqrt(2);

A=[1 1 0 0 0 0 1;-1 -1 1 0 0 0 0;0 0 0 0 1 0 -1;0 0 0 -1 -1 -1 0;-R1 -j*Xc1 0 0 0 0 0;-R1 0 -j*Xl1 0 -j*Xc2 -j*Xl2 R2;0 0 0 R3 0 -j*Xl2 0];

B=[0;0;-I;0;-E;-E;0];

currents=inv(A)*B

And here is result:

currents =

0.119418419544646 + 0.016999509142969i
-0.117492172684008 - 0.004019595549224i
0.001926246860638 + 0.012979913593745i
-0.000024074794970 + 0.001485045723510i
-0.709033028047186 - 0.012979913593745i
0.709057102842156 + 0.011494867870236i
-0.001926246860638 - 0.012979913593745i

I'm really wondering why it doesn't match with result from Multisim.

[etfpg]

Here is how I formed system of equations in my previous post:

KCL

Node 0: I1 + I2 + I7 = 0

Node 1: - I1 - I2 + I3 = 0

Node 2: I5 - I7 = -I

Node 3: -I4 - I5 - I6 = 0

KVL

LOOP 1: E - R1*I1 - j*Xc1*I2 = 0

LOOP 2: E - R1*I1 - j*Xl1*I3 - j*Xl2*I6 - j*Xc2*I5 + R2*I7 = 0

LOOP 3: R3*I4 - j*Xl2*I6 = 0