Review of the problems related to failure of metal resistor in power transformer neutral

Abstract

In case of a neutral-grounding resistor failure, the low impedance grounded network become ungrounded. This can lead to a very high level of transient overvoltages due to intermittent arcing faults. Also, in the dominant cable networks, there is a possibility of earth fault current extinction. In this way, places with weakened insulation, which may be the cause of multiple failures, are created in the network. Accordingly, the paper points out the necessity and affirmation of existing solutions for continuous monitoring of neutral grounding resistors, also proposing a universal technical solution.

Keywords

• medium voltage network
• metal resistor
• grounding
• integrity monitoring
• ground fault protection