Integrated back-up protection based on substation area information

A new scheme of integrated back-up protection based on substation area information is presented, which uses the intelligent substation technology and overcomes some shortcomings of the traditional back-up protection. The integrated back-up protection system includes all the substation equipments and the transmission lines, it integrates the measurements of each equipment, and the local information including directional elements, the circuit breakers and other status information throughout the substation. On the basis of integrated back-up protection, a new method of fault location based on direction matrix is proposed. Then, the detail information about the protection system structure, principle of the method and the tripping strategy is presented. Finally, the cases study prove that the scheme could easily achieve the following functions: The quick local back-up protection on condition that the main protection refuses to act; The breaker failure protection; Forwarding the information which have been processed in local substation to the wide area back-up protection. Analysis shows that the algorithm can achieve the desired functions and the scheme is simple and good traits on fault tolerant and expansion.