Transformer Core Nonlinearities Modeled in Harmonic Domain

This paper demonstrates the results of implementation and verification of an already existing algorithm that allows for calculating saturation characteristics of single-phase power transformers. The algorithm was described for the first time in 1993. Now this algorithm has been implemented using the DIgSILENT programming language (DPL) as an external script in the harmonic domain calculations of a power system analysis tool PowerFactory. The algorithm is verified by harmonic measurements on a single-phase power transformer. A theoretical analysis of the core nonlinearities phenomena in single and three-phase transformers is also presented. This analysis leads to the conclusion that the method can be applied for modelling nonlinearities of three-phase autotransformers