Analysis of ferroresonance in three-phase transformers

In this paper we present a technique for the analysis of ferroresonance in large power system transformers. The core of the technique involves modeling the nonlinear system in terms of harmonic variables which best highlight the limit cycle behavior. From an analytic point of view, the resulting model is convenient because it is time-invariant, and it allows relatively easy calculation of steady-state behavior, stability analysis, and construction of bifurcation diagrams. This work is a significant extension of our previous work in which we perform a similar analysis on models of single-phase transformers. This novel analytic approach to the study of ferroresonance in three-phase transformers reveals more complicated behavior than is noted in the single-phase case