2. Classification of ferroresonance phenomena

A number of cases of ferroresonance have appeared in electrical networks, and time records of the signals (voltages, currents, etc.) are available from on-site measurements. Specific tests on models and numerical simulations have also been used to build up this database of examples [1][3] . Analysis of these different signals enables them to be classified into 4 distinct types:

• fundamental regime (normal or ferroresonant) ;

• the subharmonic regime ;

• the quasi-periodic regime ;

• the chaotic regime.

Signals are classified in the steady state, i.e. after the transient has ended....