30. December 2017

    boost converter lab report download free

    Boost converter lab report

    DC-DC converters can be tuned steplessly by changing the duty cycle ‘D’. A boost converter provides an output voltage that is greater than the input voltage.

    (1) Adjust the duty cycle’D‘ by changing the control-current’s amplitude at the upper coordinate system

    (2) Adjust the switching frequency of the PWM by changing the sawtooth-frequency in the upper coordinate

    (3) Modify the values of inductance and capacitance by changing the size of the components

    (4) Manipulate the load current’s magnitude by changing the size of the ohmic resistance in the schematic

    Boost converter lab report

    Boost Switching Converter Design Equations

    First, here are some definitions:

    The relationship of voltage and current for an inductor is:

    For a constant rectangular pulse:

    From this we can see that the current is a linear ramp, when the voltage is a constant pulse.

    When the transistor switches on the current is:

    and when the transistor switches off the current is:

    Where V D is the voltage drop across the diode, and V Trans is the voltage drop across the transistor. Note that the continuous/discontinuous boundary occurs when i o is zero.

    By equating through delta i, we can solve for Vout:

    We can also solve for the duty cycle as follows,

    If we neglect the voltage drops across the transistor and diode then:

    So it is clear that the output voltage is related directly to the duty cycle of the pulses.

    There are tradeoffs with low and high ripple current. Large ripple current means that the peak current is i pk greater, and the greater likelihood of saturation of the inductor, and more stress on the transistor.

    So when choosing an inductor make sure that the saturation current of the inductor is greater than i pk . Likewise, the transistor should be able to handle peak current greater than i pk . The inductor should also be chosen such that the it can handle the appropriate rms current.

    It should be noted that when there is a light load the circuit can slip into discontinuous mode, where the inductor becomes fully discharged of it's current each cycle. When a load is reapplied the inductor needs to recharge, and so the transistor's duty cycle increases pulling the inductor towards ground, and because of the increased duty cycle Vout decreases when we really want it to increase. This causes an instability, which is well known for boost converters, and not a problem with buck converters.

    One way to combat this instability is to choose a large enough inductor so that the ripple current is greater than twice the minimum load current. When this condition is met then the inductor is always in continuous mode.

    This can be expressed as follows:

    For higher efficiency the diode should be an ultra fast recovery diode.

    These design equations have been incorporated into a convenient Switching Converter Calculator.

    Do you need help with an electronics design? Daycounter provides contract electronics design services. Contact us to give you a quote on your electronics design project.

    Disclaimer: Daycounter, Inc. doesn't guarantee the accuracy of any of it's content. Use at your own risk.

    LabVIEW

    how to built DC-DC boost converter in LabVIEW same as that in MATLAB simulink?

    how to built DC-DC boost converter in LabVIEW same as that in MATLAB simulink?

    ‎09-04-2015 07:32 AM

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    how to built DC-DC boost converter in LabVIEW same as that in MATLAB simulink? please suggest if any options.

    Re: how to built DC-DC boost converter in LabVIEW same as that in MATLAB simulink?

    ‎09-04-2015 07:40 AM

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    LabVIEW is a programming language. That's like me asking:

    how to built DC-DC boost converter in PHP same as that in MATLAB simulink?

    It can of course do math and take a number and scale it up, but I don't think that is what you are looking for. Please be more specific.

    Interesting in learning all you can about automotive CAN bus communicatin? Checkout my 9 part CAN Blog series.

    Re: how to built DC-DC boost converter in LabVIEW same as that in MATLAB simulink?

    ‎09-04-2015 08:41 AM

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    I will try it using buiding through differential equations of the DC-DC boost converter .Now is that possible?

    Re: how to built DC-DC boost converter in LabVIEW same as that in MATLAB simulink?

    ‎09-04-2015 08:55 AM

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    Now is that possible?

    Still don't know what you want so it's hard to say.

    If you are new to LabVIEW here are some free training links. (at the bottom)

    Interesting in learning all you can about automotive CAN bus communicatin? Checkout my 9 part CAN Blog series.