Research Of On-line Monitoring Technology On Arrester Running Fault

The safe operation of electrical power system is the important guarantee for sustainable development of the national economy.As electrical equipment which prevents electrical power system from lightning strike and over voltage,operating state of the arrester related to the operating security of the electrical power system.So,it is necessary to find and eliminate arrester malfunction early by monitoring the running state of arrester.The running fault of substation MOA has been researched in this paper.Also,on-line monitoring system of substation MOA has been built.This system can monitor the running status of MOA in real time.Firstly,the running fault of substation MOA has been analyzed in this paper,and the key technology of MOA on-line monitoring has been researched.A set of MOA on-line monitoring overall architecture has been built.Substation MOA has been introduced in some ways,such as classification,structure,operating principle,etc.Based on this theory,the fault type and fault cause of MOA have been analyzed and summarized in this paper.Then,on-line monitoring technology has also been introduced in some ways,such as monitoring principles,monitoring method,data processing algorithm,fault diagnosis algorithm,etc.The monitoring method which combines the digital harmonic method with double "AT" method has been selected.A set of on-line monitoring system architecture which has three discrete layers(station control layer,spacer layer and process layer)has been built.Then,monitoring terminal has been designed in hardware and software aspects,and a set of monitoring terminal which puts FPGA as the core control device has been designed in this paper.In hardware aspects,original signal is obtained by using active cross-core current transformer.After processed by amplifying circuit,filtering circuit,blockying circuit and A/D sampling circuit,the signal is send to FPGA for digital signal processing.After that,processed data is sent by RS-485 communication circuit.The software system use Verilog for modularization programming.Software system includes system control module,A/D sampling module,frequency measurement module,FFT algorithm module and lightning counting module.Also,IED which is used for protocol conversion has been designed.A monitoring center expert software called JPower2000 witch is used for substation on-line monitoring has been improved.So far,on-line monitoring system of substation MOA has been designed.Finally,by analyzing the system test and field running instance,the precision and running status of on-line monitoring system have been verified in this paper.The test results and field running data have showed that this on-line monitoring system is running in a good condition,and the precision meets the requirement.