DESIGN OF GROUNDING REACTOR

Grounding reactors are protective devices used in power system. Solid grounding was the earlier practice. It gave rise to high current to earth on occurrence of a fault. Later developments were intended for reducing the fault current under sustained fault condition. The arc suppression coil, also called Peterson coil is a particular form of grounding reactor which forms a resonating circuit with the line capacitance on occurrence of a single-line-to-ground fault. The variable reactor is tuned for resonance. This equipment drastically reduces the fault current- even power may be catered for some time under the condition of fault from the healthy lines. Air-core dry-type reactors do not utilize an oil insulation system. They are friendly with the environment and there are no fire hazard concerns. Furthermore, air-core dry-type reactors are essentially maintenance-free. The paper presents the design methodology of such arc-suppression coils, leading towards optimization.