Theses and Dissertations Collection

The demand for installation of air core reactors to provide shunt compensation to nullify the capacitance effect created by high voltage long transmission lines or cables has increased in recent years. Air-core reactors consist of bulk coils of copper or aluminum with many turns that can be prone to inter-turn faults on the windings as the insulation ages. These faults are hard to detect for cases with a small number of windings shorted due to small current changes visible at the terminal. Current protection elements have trouble reliably detecting these faults. Inter-turn faults on a winding can lead to high localized currents which can further damage surrounding insulation due to overheating and cascade to more severe faults. This research seeks to develop a sensitive fault detection scheme to allow isolation of the circuit. Two solutions are proposed based on the design of a reactor installation at a local utility and partially validated through computer simulation and a lab scale hardware demonstration. The proposed solution can be applied in the field to protect dry type air core reactors for turn-to-turn faults.