Analysis of Detailed-Phasor and Phasor-Phasor Model of Phase Shifting Transformer Using On-load Tap Changer

The paper deals with the development and analysis of the MATLAB model of a phase-shifting transformer (PST). Two separate cases of delta-hexagonal transformers are taken to be built and their performances are compared to analyze the gain in speed of simulation due to differences in the type of PST model used and developed. In the first case, one transformer is phasor type and the second transformer is detailed type thus using the detailed-phasor simulation method whereas in the second case, both transformers are built using the phasor-phasor simulation method-based model. Simulink model cases are built twice and on-load tap changers are specifically used for the operation of phase shifting of the deltahexagonal PST. In both cases of simulation, phase shifting transformers are interconnected to two networks of 120 kV with a rating of 1000 MVA. The impact of phase shifting on the transfer of power is observed and results are obtained for various tap positions, phase current, superposition of voltage at different buses, phase shift of voltage at output terminals, and active power. The aim of the experiment is to analyze the abovementioned parameters and how fast the model runs when the detailed model of the detailed-phasor case is replaced by the phasor model to give phasor-phasor model-based simulated outputs.