Fuzzy logic based multistage relaying model for cascaded intelligent fault protection scheme

摘要

Designing an instrument protection system has been considered as one of the most challenging domains in the power system. Intelligent tripping mechanism has been introduced in few sectors for controlling the moving contacts of a single operating relay connected to an electrical system. In this work, we have developed a cascaded relaying for a priority based decision making fuzzy inference system with fault tripping mechanism for controlling multiple operating relays. To obtain this priority based design of intelligent relaying, a multistage cascaded relaying is considered for achieving the higher accuracy. In this paper, we have discussed regarding the simulation of a load priority based tripping mechanism incorporated intelligent relaying. The differential equation achieved from the stage - I relaying simulation model of measurement blocks and fault generator blocks have been discussed. We have validated the stage - I relaying of the entire concept of the design with the mathematical modeling and also the simulation results of the stage - II output. The proposed method utilizes the concept of two stage relaying by introducing a Fuzzy Inference System designed to control the isolator state for the particular multistage based cascaded intelligent fault protection scheme.