Forums » Electrical Engineering

80 MVA transformer paralling with different grounding type

    • 1 posts
    June 24, 2019 1:15 PM PDT

    Hi Gents,

    we have currently 80 MVA transformer and we are going to upgrade one more 80 MVA as parallel but with different grounding.

    Existing Transformer #1
        80 MVA
        11%
        110kV/32.5kV
        YNd1

    New Transformer #2
        80 MVA
        11%
        110kV/32.5
        YNd11

    can somebody advise me how to paralleling these two transformers? Does different grounding type effect in order to parallel?


    thank you

    • 148 posts
    June 24, 2019 1:54 PM PDT

    Paralleling tranies can be difficult and many rules must be followed.  Here- read this

     

    http://ecetutorials.com/transformer/conditions-for-parallel-operation-of-transformers/

    • 25 posts
    June 24, 2019 7:53 PM PDT
    Dennis Alwon said:

    Paralleling tranies can be difficult and many rules must be followed.  Here- read this

     

    http://ecetutorials.com/transformer/conditions-for-parallel-operation-of-transformers/

    I think the OP is asking for how to do the connection.

    • 89 posts
    June 25, 2019 9:46 AM PDT

    I think he means transformer groups not grounding. The grounding would be the same with either group.

    Theoretically, with a YNd1 & YNd11 one would be connected 1-2-3 & the other connected 3-2-1.

    Other transformer characteristics must match as well.

    • 37 posts
    June 25, 2019 10:14 AM PDT

    • 25 posts
    June 25, 2019 1:43 PM PDT

    I agree with Steve.  The 'different grounding type' statement threw me off too.