Ferroresonance in Voltage Transformers: Analysis and Simulations

Power quality and power disturbances have become an important increasing factor throughout electrical networks. Ferroresonance is one of these disturbances that can occur on distribution systems, causing quality and security problems. This paper analyzes the ferroresonance as a nonlinear resonance phenomenon of erratic nature and difficult prediction. The theoretical principles of this phenomenon and the particular symptoms that identify it will be thoroughly studied. Besides, due to its nonlinear behaviour, several ferroresonance analysis methods commonly used are presented. The theoretical principles are supported by several simulations based on the overvoltage behaviour of voltage transformers.