Design And Application Of Intelligent Circuit Breaker Algorithms For Typical Swiching Stations

According to the construction of distribution network automation,especially in large-scales application of distribution switches,we have set up the information modeling of DTU distribution terminal on the basis of its' traditional functions.Meanwhile we have completed the fabrication of hardware circuit,through studying the selection of key chips in the hardware circuit design of DTU.In order to enhance the integration level of intelligent circuit breaker,we also have done a design on the structure of integrated intelligent circuit breaker,and improved the intelligent protection algorithm on both reliability and speed aspects.On the basis of reading a large number of domestic and foreign literature,the three-tier information model of DTU distribution terminal is studied in depth.On the basis of constructing the information model,the core chip of the key hardware circuit of DTU device is selected,and the key circuit of DTU device is made.In this paper,the problems of complex structure,low integration and large space occupation of traditional intelligent switchgear external equipment are studied in depth.According to the idea of integration,the overall structure design of integrated intelligent circuit breaker is completed.The internal modular structure is divided into electronic transformer,control unit,high voltage side power supply and LAN communication according to its functions.This paper focuses on the analysis of the slow response speed and low reliability of the existing two-point product algorithm and full-wave Fourier algorithm for intelligent circuit breakers.On the basis of the full-wave Fourier algorithm,the six-segment and twelve-segment integral protection algorithm is constructed,which further improves the operation speed of the algorithm on the basis of ensuring the reliability of the protection algorithm.The simulation results show that the two improved protection algorithms have obvious advantages in reliability and speediness.Compared with the six-segment protection algorithm,the twelve-segment protection algorithm has faster response.Finally,the protection algorithm of intelligent circuit breaker is determined.This paper analyses the isolation of fault area and restoration of power supply in non-fault area by DTU device cooperating with main station control distribution switch under the condition of tie-line fault,load switch outgoing fault and circuit breaker outgoing fault of typical double power supply hand-held loop network.The new protection algorithm is tested on the experimental platform,which further verifies the validity of the protection algorithm.