Failure Scenarios of Power System Protection

The power system protection plays a decisive role in defending the power system from damages that might be incurred due to faults by fault identification, isolation and clearance. In this work, the power system protection has been analyzed for a transmission line equipped with a phasor measurement unit (PMU)-based auto-recloser. A Petri net (PN) model is used to exemplify the qualitative performance measures of the protection system model through behavioural properties such as conservativeness, reachability, properness, safeness, and boundedness. Thereafter, the PN model developed has been extended for an ideal transmission line protection system to derive failure scenarios in protection system that result due to three of its important components: relay, circuit breaker and auto-recloser device. The failure analysis is necessary for yielding appropriate solutions to failures, improving system design, introducing a new device to aid the system functionality, and aiding the recovery process, which eventually leads to a more reliable system. Therefore the sole aim of this paper is to provide accurate modeling for the failures to alleviate the process of power system protection.