Fast and secure breaker failure detection algorithms

In a power system, every apparatus is equipped with a primary protection to detect faults and isolate the equipment by opening the circuit breaker. Breaker failure (BF) protection is employed as a means of local backup protection to detect failure of a circuit breaker. In this research work, a critical challenge facing numerical BF relays namely longer reset time of current based BF algorithms is examined by means of simulations and realistic experiments. Two new fast resetting algorithms for BF protection with reset time of less than half a power system cycle are proposed as means of enhancing BF protection. Simulations and experiments reflecting realistic conditions were used for performance evaluation of the enhanced BF algorithms. The proposed algorithms have a reset time of around half a cycle compared to 2-3 cycles in the case of a commercial numerical BF relay selected. Results indicate that the new algorithms significantly enhance the numerical BF protection.