Ferroresonance (damping) resistors are used in nonlinear resonance events in power systems. For ferroresonance to occur, the circuit must include a saturable inductance, a capacitor, and a resistor. A change in the value of any of these elements causes a sudden rise in current and voltage in the others.
Description
Ferroresonance begins some switching events such as; load rejection, energizing or de-energizing of transformer, switching of circuit breaker. The causes risk to it can be listed as follows:
- Idling or operation on low load on the systems grounded neutral point
- Insulation faults
- Overloading or idling of voltage transformer
- Switching one or two phases
- Dissymmetry caused by connection errors
- Switching transformers or capacitors
- Connecting low load power transformers to network with short circuit load
- Long and / or capacitive cable feeding a transformer
- Streak of lightning on transmission lines
Advantages
- High cooling surface
- Light and compact design
- Long-lasting mechanical and electrical design
Application Areas
- Voltage Transformers
- Power Transformers
