DIRECT CALCULATION OF THE STABILITY DOMAINS OF 3-PHASE FERRORESONANCEIN ISOLATED NEUTRAL NETWORKS WITH GROUNDED-NEUTRAL VOLTAGE TRANSFORMERS

Stability domains of ferroresonant oscillations must be computed and, if needed, countermeasures must be taken in order to avoid serious dam age to the power networks' equipment, In this paper, Clarke components are used to write the equations of a representative three-phase circu it under a canonical form and give a simple physical interpretation of the three-phase ferroresonance phenomenon, A method is proposed to ap proximate the quasi-periodic oscillations by periodic ones, The soluti ons and their domains of stability are computed by the harmonic balanc e method, An application to a field case is presented.