Research On Dynamic Characteristics And Monitoring System Of High Voltage Vacuum Circuit Breaker

With the rapid development of science and technology,the complexity of power system is getting higher and higher.In order to ensure the safe and stable operation of power system,the power system must be equipped with relay protection devices.The vacuum circuit breaker plays an important role in the relay protection devices,which directly determines whether the fault can be removed from the power grid.Therefore,the dynamic characteristics of vacuum circuit breaker and its monitoring system are studied to ensure the normal operation of vacuum circuit breaker in the power grid.The dynamic characteristics of circuit breakers refer to the time-varying characteristics of some of their own parameters.Common dynamic characteristics include vacuum degree of vacuum interrupter,rigid point of contact,rigid closing speed,travel characteristic curve of moving contact,excitation current characteristic of excitation coil,etc.This paper adopts virtual prototyping technology,which can greatly shorten the product development cycle and reduce research and development costs.In this paper,a virtual prototype model of circuit breaker is built,and its dynamic simulation is carried out.The experimental results are analyzed,and the prototype model is optimized.Finally,three factors which have prominent influence on circuit breaker prototype are analyzed.They are the stiffness coefficient of the contact spring,the preload of the contact spring and the mass of the transmission handle,respectively.The overall design scheme of the hardware circuit of the system is presented in detail.The circuit can collect the current signal of the excitation coil,the current and voltage signal of the main circuit,and filter out some noise.It provides a good condition for the processing and analysis of data by the DSP.The hardware circuit can realize remote and field operation,and transmit the collected data to the upper computer for further processing and analysis.The software part cooperates with the hardware by using the CCS software developed by TI company,and designs the flow chart,which is programmed in C language.The upper computer monitoring interface is written by LabVIEW software,which can monitor and issue instructions in real time.The paper has 59 figures,3 tables and 48 references.