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

Abstract

This paper presents a case study of three-phase ferroresonance in a low-voltage power factor correction system and investigates the influence of harmonic distortion on the occurrence of ferroresonance. Ferroresonance is an extremely dangerous and rare phenomenon that causes overvoltages and overcurrents in the system and degrades the power quality. The study is carried out on real field measurements in an industrial plant where ferroresonance occurs in the power factor correction (PFC) system at the detuned reactor. The three-phase ferroresonance analysed in this paper is an extremely rare phenomenon that has never been reported in this type of configuration. The measurement results have shown that in this type of configuration the high harmonic distortion is a necessary condition for ferroresonance to occur. In such conditions, switching on the capacitor stage triggers the ferroresonance with quasi-periodic oscillations supported by the medium voltage grid. The main contribution is the analysis of the three-phase ferroresonance in the detuned PFC system and the influence of the harmonics on the occurrence of the ferroresonance in such a case. The possible solutions to this problem and recommendations to avoid this phenomenon are discussed.

Analysis of Ferroresonance Mitigation Effectiveness in Auxiliary Power Systems of High-Voltage Substations

“…For example, publication [9] investigated ferroresonance-induced overvoltages and overcurrents in the medium-voltage and low-voltage distribution networks of photovoltaic rooftop systems. In another case, the analogous effects of ferroresonance, but in relation to a wind turbine generator, were the subject of a publication [10]. This is due to the saturation of ferromagnetic cores of devices, leading to significant overcurrents in their windings (mainly voltage transformers), and consequently to thermal damage to their insulation [11,12].…”

Diagnosis of Chaotic Ferroresonance Phenomena Using Deep Learning

“…For more information, see https://creativecommons.org/licenses/by-nc-nd/4.0/ FIGURE 1. Schematic ferroresonance circuit and its curve [10], [11], [12].…”

“…In the context of an iron core transformer, as the value of X L (inductive reactance) undergoes variation, the probability of X C (capacitive reactance) closely aligning with X L notably enhances. Equation 1gives ω, equation 2 gives magnetic flux ( ), and equation 3 gives V [10], [11], [12].…”