Buck-Boost Converter For High Voltage

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yhabibnur

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i got a project with spec:

  1. Vin=300-330 Vdc
  2. Vout=aprox. 312 Vdc
  3. with load at least= 500W

So 1st i decide to built buck-boost converter but the problem is inductor current goes so high even in low voltage (w/ input 40 Vdc inductor amp rise to 6A with no load).
but the output still smooth like pure DC signal. How can i overcome this problem? can i still use the topology with modification or is there any other suitable topologies for this spec?
 

Not clear what the implemented buck-boost topology is. Too high inductor current can be caused by inappropriate inductance value or wrong control scheme. Please give more information.
 

Not clear what the implemented buck-boost topology is. Too high inductor current can be caused by inappropriate inductance value or wrong control scheme. Please give more information.

based from my calculation (buck-boost formula on daniel w hart) Fsw=15kHZ



Fsw=15kHZ
my inductor should be above than 900uH to operate at CCM, so i think use 3mH is not problem
and capacitor with at least 1mF. For my topology is non-isolated buck-boost converter like circuit below



im very sure about my control scheme forming square wave without spike or other noises.
 

I can't reproduce your 900 µH CCM limit calculation, please check. 3 mH should be O.K.
 

Here is your 15khz buckboost in the free download LTspice.....just change to .asc, and hit running man icon
 

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  • BuckBoost _GND output_15khz.txt
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