Fault Diagnosis Based on Fuzzy Relations Using Protective Relays and Circuit Breakers

Abstract

In order to deal with the incomplete information and uncertainties imposed on fault section diagnosis, this paper proposed a fault section diagnosis method based on fuzzy relations for power generation stations, substations and transmission lines. The proposed method utilizes information of protective relays and circuit breakers to build sagittal diagrams which represent the fuzzy relations for power stations, substations and transmission lines. It diagnoses the faulted sections correctly for complicated multiple faults as well as simple faults. The proposed scheme also examines the mal -operation of circuit breakers based on the relays information and determines the faulted section (item). The section's possibility of being faulty is given by degree of the membership of the fault section candidates. Computer simulation of a real system such High Dam power station (Hydro Plants Generation Company HPGC) in Egypt shows that employing this type of diagnosis is useful in diagnosing faults that have uncertainty. Hence, it helps the control center operation engineers to make a reasonable decision and strong practicability of fault diagnosis methods to the real power station.