An Augmented Jacobian Framework for Multiphase Power Flow with Special Transformer Configurations

Transformer models are important components of power systems. Under certain configurations, incorporating transformer models with the nodal admittance matrix of the power flow (PF) formulation makes it singular, rendering the resultant PF algorithm unfeasible. This paper addresses these issues by modelling special transformer configurations (center-tap, three winding, voltage regulators) into a unique Augmented Jacobian based multiphase PF formulation. In this formulation, power system components can be modelled with PF constraints independently and accurately resolving associated singularities in classical nodal admittance matrix. The proposed method is evaluated on two IEEE feeders (modified IEEE-9 bus and IEEE-8500 node). Results are validated with benchmark published results and IPSA software. Numerical examples confirm the effectiveness of the proposed models and algorithm in successfully resolving matrix singularity.