Three-phase transformer modeling for forward/backward sweep-based distribution systems power flow algorithms

This paper provides a new approach for modelling of distribution transformer in the forward/backward sweep-based algorithms for unbalanced distribution systems. For the transformer modelling symmetrical components theory is used and zero sequence-voltage and -current updating for the sweep-based methods is shown. The validity and effectiveness of the proposed method is demonstrated by a simple two-bus balanced and unbalanced system for grounded wye-delta and delta grounded wye transformer connections. Results are in agreements with the literature and show that the proposed model is valid and reliable.