MiCOM P633

[Carlos5]

Hi everyone,

I’m working with a MiCOM relay and I have a question about the setting “Vec.gr.ends a-b PSx”.

The case is a Dyn1 transformer where the HV side is supplied in negative phase sequence. I’m also using the “Phase sequence” setting configured as A-C-B, with standard connections everywhere else.

I’ve gone through the manual several times, but it’s not clear to me whether in this case I should set “Vec.gr.ends a-b PSx” to 1, assuming the negative sequence supply is already accounted for by the A-C-B phase sequence setting, or if it should actually be set to 11.

Any clarification or experience on this would be greatly appreciated.

Thanks in advance!

[Arun-kumar_PS]

Hello @Carlos5 

The Vec.gr.ends a-b PSx should be configured as 1, in line to the transformer vector connection. The reverse phase sequence is not going to change this, the A phase will be in the same position irrespective of positive or negative phase sequence. The LV side connection should follow the same reverse phase sequence.