PSpice, problem with simulation PLC

Discussion in 'Homework Help' started by McBucek, Jan 8, 2015.

  1. McBucek

    Thread Starter New Member

    Jan 8, 2015
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    Hi,
    I work with PSpice 16.3. for my school project. I have to simulate PLC (power line communication) device. I want to extract high frequency signal, from power line network using band pass filter. So I have created band pass filter. Put two sources (one with 50Hz and the second one with 100kHz) and also I have try to simulate the rest of the power line (parametres are count for 3 km from avarage values for power line 22kV). But there is a problem. I think PSpice doesn´t see it all like one object. And that I have created something like weird low pass filter. And I can´t replace it just by resistor, because it's not correct.
    Do you have any advice, how can I simulate power line, or if PSpice contain something like impedance Z?? Or did I just make some stupid mistake??
    I will be grateful for any advice and if I forget write some information about my circuit, I will add it as soon as possible.
    Thanks.
     
  2. crutschow

    Expert

    Mar 14, 2008
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    What exactly do you expect to see from the output?
     
  3. McBucek

    Thread Starter New Member

    Jan 8, 2015
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    I need to have high voltage (in the picture it is 50V, 50Hz) behind the "power line"(the power line is created by replacement scheme) and the low voltage (5V, 100kHz) behind the band pass and transformer. So I need to separate LV with high frequency from HV.
     
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Back to basics. Nothing to do with simulation, which gives you garbage out if you put garbage in.

    What happens when you parallel two ideal voltage sources?
     
  5. McBucek

    Thread Starter New Member

    Jan 8, 2015
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    Damn, it's stupid mistake. thx. But I still have the same problem. Graps didn't change so much.
     
  6. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    First the Bode plot where the stimulus is 1V swept from 50Hz to 200kHz. Note the nice peak at the receiver input at 100kHz. Note the attenuation of the 100Khz carrier across the 500Ω load.

    267.gif

    Now, here is how to inject the 100kHz carrier on top of the 50Hz power. Note the voltage developed at the load and at the receiver.
    1Vpp at 100kHz produces 12vpp at the receiver.

    267a.gif
     
  7. McBucek

    Thread Starter New Member

    Jan 8, 2015
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    Ok, but as the load you used resistance right? If I use just a resistance and not a replacement scheme of power line as a load, it's work fine. But I am curious, if there is anything like common load in PSpice.
     
  8. MikeML

    AAC Fanatic!

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    What do you mean by "common load?
     
  9. McBucek

    Thread Starter New Member

    Jan 8, 2015
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    I mean, that replacement scheme of power line causes problems in the simulation (in PSpice it's look like some kind of band pass). So if PSpice contains something like characteristic impedance or surge impedance of power line. Or some logical function, where can I write the equation for that.
     
  10. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    You can always model the Transmission line using lumped R,C and L.
    If you have a function that describes your line in terms of S or jω, you can use the PSpice Behavioral Voltage source to model the line.
     
  11. McBucek

    Thread Starter New Member

    Jan 8, 2015
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    Ok I am going to try it. Thank you
     
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