Evaluation of neutral voltages in arc suppression coil systems

摘要

Although arc suppression coil systems are able to detected high impedance ground faults by monitoring the neutral voltage, there are other system abnormalities which can also cause a change in the neutral voltage. The causes of abnormal neutral voltages in arc suppression coil systems are analysed and criteria are developed to differentiate between them based on the phase angle and magnitude of the neutral voltage. Using the criteria developed in this paper, modern computerised protection systems will be able to automatically take appropriate action based on the type of system abnormality, immediately, when a system abnormality occurs.