Predicting arc faults in distribution switchgears

Due to the wide dependency on electricity in our daily life, it is highly desired to have an uninterrupted and reliable supply of electricity for domestic, commercial, transportation, industrial and healthcare purposes. An arc fault occurring in switchgear causes long duration power interruption, damage to the equipment and hazard to personnel. Several arc protection systems have been introduced during last decade, mostly relying on reactive protection techniques. This paper introduces some unique methods detecting incipient faults leading to arc-flash in medium voltage (MV) and low voltage (LV) switchgear and motor controlgear. In MV switchgear, low power arcing and insulation degradation can be detected by differential electric field sensor (D-dot) and Rogowski coil (RC), and thermal degradation is detected by thermal ionization detector (TID) in LV switchgear. On-site testing is included in this paper to validate the laboratory test results.