OPEN WYE-OPEN-DELTA AND OPEN DELTA-OPEN DELTA-TRANSFORMER MODELS FOR RIGOROUS DISTRIBUTION-SYSTEM ANALYSIS

This paper presents mathematical models of open wye-open delta and open delta-open delta transformers for rigorous distribution system studies. The copper and core losses, winding connection, phase angular displacement between primary and secondary windings, and off-nominal tapping are all taken into account in the proposed models. Because open wye-open delta and open delta-open delta transformer banks are quite often used in distribution system, for analysing a distribution system in detail the modelling of these transformers are therefore required.