Turn-to-Turn Fault Protection for Dry-Type Shunt Reactors

Air core reactors have several applications in the power industry. Shunt compensation for long transmission lines under light loading is common application of the air core reactors. They are cheaper than oil filled shunt reactors, modular and simple in design. Protection of the air core dry type shunt reactors is very similar to the protection offered for a regular oil filled reactor [1] [2]. However, turn-to-turn faults are more easily detected in oil filled reactors than in dry-type reactors as the former uses mechanical protection devices and gas monitoring to detect such faults. Dry-type reactors have no such installations and rely on simple directional ground overcurrent protection to detect such fault. This research provides a protection philosophy to detect faults with better sensitivity than the industry standard of 10% in dry type air core shunt reactors. Performance is tested through simulation and hardware test results.