Advice on DC-AC variable frequency inverter

Discussion in 'Power Electronics' started by bman2, Oct 2, 2016.

  1. bman2

    Thread Starter New Member

    Dec 18, 2015
    7
    0
    Hi,

    For long time I had an idea of making electric gocart/buggy for myself as a hobby, I'm an electrical engineer but never had experience with designing after college.
    First thing would be the electric drive part. I have a 2kW squirell cage induction motor at home already. I know its weak but its good for beta version and testing. I would buy about 200Ah 12V dry "solar" battery for testing purposes of this. But generally the idea is it being 12V DC, to 230V AC single or 3 phase, variable frequency drive.

    So my ideas of controlling the motor go 2 ways;

    1. Frequency control of inverter, sine wave
    a) Boost converter for 12V DC to about 300V DC if possible, then variable f inverter.
    b) Convert 12V DC to 12V AC variable f, and have a power transformer 12V/230V before the motor itself.
    c) Get some sine wave function generator with variable frequency and use transistor as an amplifier of that signal, being amplified with power from the battery, and using that amplified sine wave signal for the motor.

    2. Amplitude control of the voltage
    b) Regular 12V DC from battery, or higher DC after boost converter, getting chopped by a transistor, smoothened by a capacitor bank, and sent to 50Hz inverter without variable frequency.


    For idea #1 above, I would like if there is an IC that has an input for frequency control and variable frequency output for mosfet gate drivers. Then I'd have 2 main ICs, all the filters and control components they need, on a single board. 6 pulse bridge with its filters on power electronics part with coolers phisically seperated from control logics.

    At this point I would even consider buying a complete solution VFD so it all runs while I'm fiddling with my own DC to variable AC solution, but I'm not finding a VFD anywhere that runs off from 12V DC, they all seem to run from mains AC.
     
  2. bman2

    Thread Starter New Member

    Dec 18, 2015
    7
    0
    Thinking about it for few hours now, I'm not sure I'd want to build a speed control system that changes only f or only V, it needs to change both to be proper, I'll have to look into it a bit more, maybe buy myself a Arduino and see where that takes me.
     
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