Research On On-line Monitoring And Intelligent Fault Dignosis Method For HVCB

As a key component of high-voltage power grid,high-voltage circuit breaker(HVCB)is responsible to control and protect the normal work of power grid.Once failure occurs,it is likely to cause huge power loss and economic losses.In recent years,with the construction of smart grid and UHV project,reliability and security requirements for HVCB grows more stringent.It becomes essential to realize a reliable state maintenance of HVCB.State maintenance includes on-line monitoring and failure diagnosis.Online monitoring is the basis of state maintenance while fault diagnosis is the soul part of the state maintenance.With the combination of online monitoring and failure diagnosis,a comprehensive state maintenance of HVCB is achieved,which meets the requirements of smart grid and UHV project.According to the latest research progress at home and abroad,in this paper,it starts from common faults of HVCB,choosing representative online monitoring state quantities and using high precision sensors to achieve the accurate,reliable and real-time purpose of on-line monitoring.In failure diagnosis,firstly,according to different type of raw data,features of state quantities is extracted using Hilbert-Huang transform improved by AR model to forecast the next number of terminals.Furthermore,the improved HHT is compared with the WT to certify the progressiveness.And then,by using the gray relational analysis method,the weight coefficient of each of index is introduced.According to the improved gray correlation analysis,the failure of HVCB is finally identified due to the correlation degree.Through tests,the proposed method is of high accuracy and reliability.In order to apply the circuit breaker on-line monitoring and intelligent fault diagnosis method,in this paper,a prototype is also built,which has the characteristics of integration and modularity,divided into two parts:the host computer and the lower computer.The host computer mainly completes the state data feature extraction and fault diagnosis,while the lower computer is responsible for online monitoring.That how the prototype complete the mission of on-line monitoring and intelligent fault diagnosis was introduced from the aspects of hardware and software After field test and type test,it proves that the proposed system can complete the task of online monitoring and failure diagnosis in the complex environment of HVCB,while providing the foundation for background control and unmanned power station.