What is ferro-resonance?

Ferro-resonance is a phenomenon that occurs in electrical power systems when there is a combination of saturable magnetic materials, capacitors, and inductors. It can cause a significant increase in the voltage level of the system, leading to damage to equipment and potential hazards to people.

Ferro-resonance occurs when the system is at or near resonance, where the reactive power flows between the capacitive and inductive elements of the system and is magnified by the non-linear behavior of the saturable magnetic materials. This effect can cause the voltage to increase several times over the normal operating level, leading to electrical insulation breakdown or component failure.

Ferro-resonance can be caused by a variety of factors, including lightning strikes, switching operations, and load changes. Prevention and mitigation strategies include using protective relays, reducing the voltage of the system, modifying the circuit design, and controlling the saturation of the magnetic materials.