MATLAB: Verification of Superposition Principle

[Bloopy]

Homework Statement

Verify Superposition Principle using Matlab, given a DC source of 100V, an AC source of 50V, 60Hz and three resistances, R1=10 ohms, R2=20 ohms and R3=15 ohms.

I created the circuit below and ran the program. Result:

Homework Equations

None, just running the program.

The Attempt at a Solution

Now, the Principle of Superposition states the total current in any part of a linear circuit equals the algebraic sum of the currents produced by each source separately. I am trying to verify the current flowing through R3 = 15 ohms resistance.

1. I short circuit the DC voltage source and run the program. Result:
   
   
   
2. I then short circuit the AC voltage source and run the program. Result:
   
   
   
   
   
   As clearly can be seen, the Superposition Principle is not verified. I am unable to reason where the discrepancy is.

 

[DrClaude]

I'm not the best with circuits, but I don't understand your result when you short-circuit the DC source. How can you measure 94.4 V in that circuit?

 

[Bloopy]

I'm not the best with circuits, but I don't understand your result when you short-circuit the DC source. How can you measure 94.4 V in that circuit?

Yeah, I altered the step-size to get the accurate value of RMS voltage. Edited the question.

 

[lewando]

I created the circuit below and ran the program. Result:

The Current Measurement block is processing a current waveform with both AC and DC components. The block outputs the instantaneous current Not sure how this block will represent a static value of an AC current. What happens if you use an RMS block right before Display3?

 

[Bloopy]

The Current Measurement block is processing a current waveform with both AC and DC components. The block outputs the instantaneous current Not sure how this block will represent a static value of an AC current. What happens if you use an RMS block right before Display3?

Sorry for the delayed replies, I am in college for 12-14 hours during the day.

 

[lewando]

So what is now displayed is the RMS value of the combined AC and DC currents. You should be able to verify this result by using your single-source results and a googleable formula for determining the RMS value of an AC signal with a DC offset.