Adding vectorgroup dynyn to 3w-transformer

[nis-bucr]

Problem

The vectorgroup Dynyn was currently not supported for shortcircuit calculations of three winding transformers

Fix

Added the vectorgroup. Also fixed bug with vectorgroup Ynyy.

[vogt31337]

@nis-bucr thanks for this patch. Could you by any chance update the changelog?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.84%. Comparing base (28168c4) to head (fd2cae5).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #2283   +/-   ##
========================================
  Coverage    75.84%   75.84%           
========================================
  Files          284      284           
  Lines        33690    33697    +7     
========================================
+ Hits         25551    25558    +7     
  Misses        8139     8139           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[nis-bucr]

@vogt31337 Thank you for the review. I added the changelog message to upcoming release, hope this is correct.

[vogt31337]

@nis-bucr thanks for updating. CodeCov reported that there is no test covering your changes/additions. Could you by any chance add a simple test for your dynyn 3w transformer?

[nis-bucr]

@vogt31337 I added a test to test_1ph.py for the dynyn vectorgroup. Could you please verify the values with your commercial calculating tool used for the other vectorgroups?

[vogt31337]

@nis-bucr, thanks for updating!
@pawellytaev, could you verify this calculation with PF?