Continuity of supply improvement by means of circuit breakers along MV lines

This paper proposes a method to find the most effective point where install a MV circuit breaker along the lines to improve the continuity of supply measured by means of the following indicators: a) cumulative duration of long interruption per LV customer; b) number of long and short interruptions per LV customer. The following pages describe a method to localize the phase to phase short-circuits faults knowing the intervention threshold of the maximum current relay associated to the circuit breaker installed at beginning of MV feeders. The phase-to-phase faults percentage for each MV line and the probability for one fault to occur in a determined distance from the MV bus-bar are evaluated as well. Finally a way to obtain the maximum advantage for the continuity of supply with the use of all mentioned data and information is determined.