step up boost converter

Discussion in 'Electronics Resources' started by hina gohar1302, Feb 7, 2014.

  1. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    I have to implement this circuit analytically and numerically in multisim for my research work..I need help in circuit analysis equations and then in software simulation..how to implement this circuit in multisim for solar panel application..in paper it is mentioned that oscillator 3 winding transformer will be connected to base emitter junctions of both transistor in simulation..which transformer I should used multisim library components and how to connect this with step up converter ...how to vary duty cycle in multisim..
     
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  2. crutschow

    Expert

    Mar 14, 2008
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    The paper you referenced is about a switched-capacitor voltage converter, but you also mention oscillators , transformers, transistors, solar panels and then questions about how to use Multisim. Your questions are way too general and disjointed to be readily answered.

    First you need to break the problem into smaller, manageable parts, thus its very important that you generate a block diagram with the various blocks showing specific tasks so it can be understood what needs to be done to achieve the desired complete goal. If the blocks perform a complex function then you may need to add additional blocks inside to further simplify the individual tasks. Without doing that you are just spinning your wheels. After you have a complete block diagram, you can then ask specific questions about those blocks, if you need to, which are more likely to be answered by someone on this forum.
     
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  3. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    No actually the circuit in this paper is inductorless boost converter not for any specific application.I have to design this circuit for solar power system for constant output..for this I need help.I implemented same circuit in multisim for verification results but on output not getting any voltage.Is there any problem in the circuit or how I modify the circuit to get constant regulated output from unregulated variable input..Blocks will be 1)Solar panel 2)Charge controller i.e switched capacitor boost converter 3)battery 4)inverter..Currently I am working on designing of boost converter but it should be inductorless and provide fixed particular value output..how I can proceed..Please hide my post from site or paper
     
  4. crutschow

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    Post the circuit diagram you have.
     
  5. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    circuit is the same which I sent in my 1st post that pdf file of inductorless boost converter..I am trying to attach multisim simulation file but not succeded
     
  6. crutschow

    Expert

    Mar 14, 2008
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    Try converting the simulation schematic to a standard format such as .PDF, .GIF, etc. (not JPG or JPEG) to download (use the Go Advanced window and click on the paperclip/Attachments).
     
  7. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    oky thanxs..I successfully converted into gif format..kindly have a look.sort out problem
     
  8. crutschow

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    Mar 14, 2008
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    For starters you always need at least one ground connection with a Spice simulator. Spice does not like floating circuits. I don't see a ground in your circuit.
     
  9. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    yeh I attached gnd now it is working properly for 12volt input it is giving 22volt..but when run first time on oscilloscope output comes irregular i.e. ripples (zero voltage) then after some time it smooths ..also how I can vary duty cycle,switching frequency,base to emitter voltage and observe their effects on output voltage,efficiency,load power,base current..coz through oscilloscope I can observe voltage only in multisim..how to record all other parameters as mentioned in paper which I attached in my 1st post..and next in ac voltage source there is no option of duty cycle or PER so how i can do that..plus in paper base emitter voltage also varied but in multisim BJT component values no option for assigning base to emitter..similarly how to define range of supply voltage and observe graphs for above mentioned parameters..or either I have to observe for all values each time by changing supply voltage,switching frequency and then in excel plot all those recorded values..or these things are possible in multisim..like we do in matlab...
     
  10. crutschow

    Expert

    Mar 14, 2008
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    The circuit takes some time to reach steady-state values after start-up. That's likely what is cause the irregular output you see.

    If you do a Transient Analysis, then you can plot as many variables as you want.

    If you use a pulse source, you can vary the duty-cycle.

    You can vary the base emitter voltage by adding a voltage source is series with the emitter and setting it to the added value you need (either plus or minus).

    Note: Please start your sentences with capital letters. It's hard to read otherwise.
     
  11. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    I can not use pulse voltage which will fed to transformer

    Can this circuit be used for solar power system.
    a) 12V variable input from solar panel goes to this switched converter (charge controller) which will step up and provide regulated constant 24V output which then fed to battery for storage and then to inverter which will drive any load.

    b)Or is there need of modification in this proposed circuit according to my literature review I found that constant output achieve through voltage feedback (controller) or some PWM technique.

    c)But I do not want to go in further complexity by using controller that's programming and interfacing tricky.
    Please hide my post and relevant data from this site
     
  12. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    I can not use pulse voltage which will fed to transformer

    Can this circuit be used for solar power system.
    a) 12V variable input from solar panel goes to this switched converter (charge controller) which will step up and provide regulated constant 24V output which then fed to battery for storage and then to inverter which will drive any load.

    b)Or is there need of modification in this proposed circuit according to my literature review I found that constant output achieve through voltage feedback (controller) or some PWM technique.

    c)But I do not want to go in further complexity by using controller that's programming and interfacing tricky.
    Please hide my post and relevant data from this site
     
  13. crutschow

    Expert

    Mar 14, 2008
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    Of course you can use a pulse voltage to drive a transformer. But you need to use a capacitor in series to block any DC component. Of course varying the duty cycle through a transformer will cause the output to have a varying plus and minus value which always has a zero DC average value.
     
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  14. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    And what about my content on this forum or posts I want to hide these from other users only visible to me and senior experts who are supposed to reply..Please hide all my private data or rather delete
     
  15. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    Please kindly inform me how my posts can delete especially 1st post in Which I attached pdf file please remove that or hide from other users.
     
  16. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    Few weeks back I asked how to vary duty cycle in that topology.You suggested use pulse source,I used pulse source to drive transformer instead of sinosuidal but on output not getting boosted output.
    Now what can I do,either that circuit is not okiee or the strategy which mentioned in paper not applicable.
    Can this circuit be used for PV application as dc-dc charger.
     
  17. crutschow

    Expert

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    Post your circuit.
     
  18. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    This is required circuit.One thing more for simulation purpose which simulator is best either Multisim or PSIM.
     
  19. crutschow

    Expert

    Mar 14, 2008
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    You circuit is not a boost circuit. It simply charges and discharges C1 between 12V and 0V. I don't know what D1 and D2 are supposed to do (?). Where did you get that circuit?

    To boost a voltage you need a transformer (other than the one you have driving the bases of the transistors) or an inductor in a normal boost type circuit, of which there are many examples posted on the internet.
     
  20. hina gohar1302

    Thread Starter New Member

    Feb 7, 2014
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    I have taken this from the attached paper which I have to reproduce numerically.
     
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