Simulation of generator protection using Matlab

A three phase synchronous machine is one of the critical and important equipment of power generating unit used in captive, co-generation and indipendent power plants(IPPs) in verious ratings. To protect the generator against power system abnormilities or fault within itself, it needs quick isolation from rest of the system for maintaining stability in power system. As generators are associated to more harmful operating conditions than any other equipment of power system, therefore sensitive as well as selective protection schemes are required. However finalization of a protection scheme requires throughout knowldge of of protection philosophy of machine as well as associated equipments. As the pace of technological change has rapidly accelerated so, In today's scenarios electromechanical type of relays are absolute which were used for each individual protection and instad of that a single multifunction digital/numrical relay with various features are used as a complete generator protection package. One of the major advantage of these relays are that these are working in a common protocol (IEC61850) irrespective of its make (SIEMENS, ABB, AREVA) and facilatate the logics blocks as per the requirement of end user. These relays are used input analoge signals from neutral side of CTs and Phase side CTs and Vts for various computations and algorithms and accepts user configurable inputs and outputs, substation control system interfaces disturbance recording, etc. In this project we are considering different protection schemes of generator and simulate each function using Matlab simulink. In above cases generator is cosidered as both dynamic as well as AC source. The pick-up of a protection function inflates opening of Generator CB and FB and shows the trip log as a function of time. Each protection function shows in different pages with events in its respective worksheet.