Research On The Arc Forming Stage Characteristics Of Vacuum Circuit Breaker Based On Image Processing

Vacuum control theory is one of the major issues in the field of vacuum circuit breaker.The valid approach to solve this issue is to further research on arc characteristics of vacuum circuit breaker and make them quantified in order to find the effective control measure.The characteristics of vacuum arc forming stage and the arc extinguish stage affect the working performance of vacuum circuit breakers directly.Arc forming stage involves the interaction of discharge,electromagnetic field and temperature field and it has a direct impact on the initial conditions in dielectric recovery stage.So this paper mainly study on arc forming stage characteristic.Vacuum arc experimental is studied through vacuum demountable chamber test device and the arc images are collected by high speed camera.The purpose of arc characteristics extraction is to process the sequence arc images firstly,then to extract the geometric features such as area,perimeter and longitudinal diameter of the arc forming stage and to analyze the static characteristics.Secondly,the changes of texture and arc density with the opening distance and the diffusion and shrinkage of arc column of arc forming stage are studied and the dynamic characteristics are analyzed.The cathode spots are the nature of the vacuum arc,which are the embodiment of the arc macro-micro characteristics.It is also one of the important parts in the research of the plasma physics.The variation of cathode spots in the combustion process has important influence on the basic vacuum arc characteristics,such as arc stability,arc voltage,corrosion rate and cut-off value.So this issue is mainly to extract the cathode spots features of arc forming stage.The spot emission angle is measured by corner detection and the cathode spots are detected by the method of local gray probability analysis and the running speed is calculated.Finally,cathode spots areas extraction algorithm based on circular feature extraction is designed and the areas of the cathode spots are extracted by the algorithm,then characteristics are analyzed.In the end of this paper,a visual system of arc forming images and cathode spots is developed by MATLAB software.The system includes images enhancement,edge detection,images filtering,morphological processing,color images analysis,images feature extraction and images analysis modules and it has the functions of images introduction,images processing and parameters calculation.Experimental results show that this method is effective and practical,also implement vacuum arc images process is automatic and intelligent.