Research On The Adaptive Generator Differential Protection

Generators and transformers are one of the most important parts of electric power system,therefore,their operations will influence many aspects of the electric power system,such as normal operation of electric power system,improvement of electrical energy quality,and etc. With the development of power industry,the number of generator is more,and the capacity of single generator is growing,and this demands higher performance for large generator protective relay.Internal short-circuit faults,which may severely damage generator,if the lack of effective protection,in the event of taking place faults will certainly cause significant damage for generator,and even may affect the steady operation of power station and the entire electric power system,therefore it's very important to implement the effective differential protection for large generators.However,when the large generator arises internal faults,the transient relation of electromagnetism will become very complex.Then it's very difficult to set up the transient simulation model for fitting to optimize generator differential protection.At present,the technology of setting up simulation model for internal short-circuit fault in large generators and the research of generator differential protection project also become important topic to research at home and abroad.Therefore,it is significant to develop a set of intelligent digital relay protection installations.In this paper,by analyzing the advantages and disadvantages of the domestic and alien current differential protection criterions,paper design an integrative criterion bases on the fault current characteristic after the breakdown.This criterions combines existing differential protection criterions and makes different criterions part work in different time after fault.Among them,the way using the direction of fault component to automatically adjust breaking coefficient is an innovation in this paper.Then setting up a synchronous generator simulation model in ATP,simulating internal fault and external fault of the generator,acquire the data of the generator faults,and compile program the adaptive generator differential protection in Matlab to verify the correctness of adaptive criterion. Finally,design generator differential protection module as core of TMS320LF2407A,and detailedly describe the design process of the hardware system and the software system.