• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 2486 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

UCC29910A: 3 Phase 400Vac (rectified DC Bus 540VDC) @5000W PFC Buck possible

UCC28070A: Best arrangement for 3 phase (400Vac) power factor correction.

Ferhat Incal
Prodigy 150 points
Part Number: UCC28070A
Other Parts Discussed in Thread: UCC28070, UCC28180

I am trying to construct a power factor correction scheme for a 3 phase 400Vac power supply.

According to previous information from TI, boost topology is suitable for industrial enviroment so that I eliminated the buck topology which may have some other advantages. 

I selected UCC28070 as the controller. (boost topology)

I do not want to use the neutral line, The power supply has to use only the 3 phases. 

What can be the best arrangement for this setup?

I send the following schematics containing 3 seperate PFC units for each phase.

Each input is between phases. This setup does not need neutral point.

Would you recommend a simpler setup containing less switches and diodes. This setup needs 3 HV igbts and 3 HV diodes. 

  • 0
    TI__Mastermind 34465 points

    Hello Ferhat:

    Have you considered combining the 3 separate stages with a 3 phase rectifier and  a single stage pfc using the UCC28180  ?

    TI does not have any reference designs based on a 3 phase supply so there is no design information or reference material available to pass on to you.

    This is only a suggestion.

    Regards

    John

  • 0 in reply to John Griffin1
    Prodigy 150 points

    Dear John,

    Attached is the scheme of the converter and correspanding phase voltage and current.

    I notice that the voltage and current are in phase, but the shape of the current is very bad. (very bad crest factor).

    As the voltage and current are not lagging or legging, the PFC IC does not need to sample the input voltage to adjust the current.

    It will be sufficient that the IC measures the current and compansates the down decaying current valley through modulating and chopping the inductor current. (as seen in the picture).

    Is my assumption right?.

    Can UCC28180 fill this camel hump shaped current (as seen in picture 1)  through modulating/chopping/arranging the inductor current. ?

    What is the most precision/effective PFC controller to fill this camel hump current and having best crest factor improvement in TI portfolio? (I assume UCC28180)

    Thank you for valueable information.

     

  • 0 in reply to Ferhat Incal
    Prodigy 150 points

    I also send the graph of the form of the current  and DC bus voltage just after the B6 rectifier. Each phase has current just like a double camel hump.

    I hope that the boost converter after the B6 rectifier can fill these current gaps.

    I mean the output of the Boost converter will look again just like this but the input of the boost converter (output of the B6 rectifier) will have a constant current.

  • 0 in reply to Ferhat Incal
    TI__Mastermind 34465 points
    Hello Ferhat,
    Your original question relates to a 3 phase implementation of a 5kW pfc .
    If you wish to use a non-pfc application with a full bridge controller you should close this post an open a new post.
    Regards
    John