Review of ferroresonance in power distribution grids

Abstract

Ferroresonance is a special case of resonance, which can occur when a non-linear inductive reactance is connected in series with a capacitive reactance. In instances of ferroresonance involving electric power distribution facilities, the inductive reactance will be the magnetizing reactance of a singlephase or three-phase transformer. The capacitive reactance will be due ordinarily to the conductor-to-sheath capacitance of primary cable supplying the transformer under favorable conditions. Ferroresonance may be accompanied by abnormally high or low voltages as a result of single pole switching of one or two phases of the source supply to the transformer. Ferroresonance is capable of producing sustained overvoltages with peak magnitudes approaching, or exceeding twice the rated peak voltage, which is harmful and unsafe for the operation of most equipment.In this paper, the various conditions giving rise to occurrence of ferroresonance will be identified. The most prevalent resonance resulting in undesirable voltage conditions will be addressed and analyzed. Also some possible means of preventing occurrence of unsafe ferroresonance in power transformers will be proposed.

Ferroresonance: An Insight Into the Phenomenon

“…Hence, it is important to identify those electrical configurations prone to the appearance of the phenomenon which is currently a problem of the utmost importance in many electrical facilities. [11], [12], [16] V. CONCLUSION Ferroresonance in power networks involving nonlinear transformers and capacitors has been well researched for nearly a century. It can be understood as a complex oscillatory energy exchange between magnetic field energy of nonlinear magnetizing inductances of transformer/reactor cores and electric field energy of nearby capacitances.…”

Effect of Harmonics on Ferroresonance in Low Voltage Power Factor Correction System—A Case Study

“…Numerous examples of ferroresonance in practice have been reported [12,[15][16][17], while the electrical system configurations in which ferroresonance may occur are identified as follows: [18,19]: (a) voltage transformer energized through the grading capacitance of open circuit breakers, (b) voltage transformer connected to an ungrounded neutral system, (c) capacitor voltage transformer, (d) power transformer supplied accidentally on one or two phases, (e) power transformer, fed through a long transmission cable with low short-circuit power, (f) power transformer connected to a compensated transmission line connected in series, (g) power transformer connected to a de-energized transmission line running in parallel with an energized line, and (h) inductive neutral networks. However, the ferroresonance triggered by the three-phase opening/closing of the circuit breaker is extremely rare [20,21]. Recent studies are concerned with modeling phenomena [22][23][24], protective measures to prevent the occurrence of ferroresonance [25][26][27], reporting of new cases [28,29] and types of ferroresonance [30].…”

Analysis of Transformer Resonant Overvoltages Due to Switching Capacitance

“…During the operation of a power system the nonlinear inductance variations due to transformer core may lead to special kind of resonance which is known as ferroresonance [3]. There are some ongoing studies conducted on ferroresonance phenomenon [4][5][6][7][8][9][10].…”