Ferroresonance in Power Systems: A Review of Causes, Impacts and Countermeasures

Abstract

This paper delves into the intriguing phenomenon of ferroresonance within electric power distribution networks. This nonlinear resonance condition can lead to significant operational disruptions. The study aims to explore the root causes, operational features, and harmful impacts of ferroresonance, especially in transformer systems that experience switching operations and lightning strikes. Additionally, it seeks to pinpoint practical strategies to mitigate these issues, ultimately enhancing equipment reliability and ensuring operational safety.

The research adopts a comprehensive review-based approach, supported by theoretical analysis and simulation studies drawn from secondary sources. It delves into distribution networks that feature nonlinear inductive elements, capacitive components, and iron-core transformers that are susceptible to magnetic saturation. By combining analytical models, previously published simulation results, and documented field measurements, the study assesses how the system behaves under ferroresonant conditions.

The analysis shows that ferroresonance is mainly triggered by certain switching setups and transient disturbances in systems that have lightly loaded transformers and a lot of capacitance. The key takeaways reveal that ferroresonance can lead to overvoltage that exceed 2.5 per unit, along with sustained overcurrent, distorted waveforms, and chaotic oscillations. These issues significantly heighten the risk of transformer overheating, insulation failure, premature aging, and, in severe cases, catastrophic equipment breakdown. The study also points out that grounding practices, system design, and surge protection strategies are crucial in reducing the chances of ferroresonant events.

Ferroresonance is a complex and unpredictable phenomenon due to its nonlinear and chaotic characteristics, which means that purely mathematical solutions aren't enough for effective mitigation. However, combining theoretical analysis, simulation tools, and real-world measurements offers practical ways to understand and manage its effects. The insights gained from this research are invaluable for system designers, transformer manufacturers, and operational teams, helping to enhance equipment lifespan, improve safety, and ensure more reliable power distribution services