Vacuum Degree Measuring Method For Vacuum Arc Extinguishing Chamber

The main function of the vacuum circuit breaker in electric power system is breaking the load,its breaking capacity is related to the safety of the whole power grid.Once the vacuum degree of vacuum chambers exceeds the minimum allowable vacuum level,it will lead to the fact that the vacuum circuit breaker can not normally open the load,or even the explosion and other power accidents,which harms the power system's operation.At present,the main research directions in measuring the vacuum degree are all focused on the single improvement for the hardware,without taking into account the comprehensive treatment of the measurement and calculation of the vacuum degree,and vacuum condition maintenance based on the intelligent management.From the point of view of improving the calculation method of the vacuum degree of the arc extinguishing chamber,this paper uses the artificial intelligence language algorithm to optimize the vacuum degree measurement and data fusion algorithm of the arc vacuum chamber,with a more accurate and feasible measurment and research method for the vacuum degree of the arc extinguishing chamber finally derived.The concept of vacuum degree state maintenance management of vacuum circuit breakers is also put forward.First of all,this paper describes and analyzes the main measuring methods of the vacuum degree of arc distinguishing chamber and the main factors that influence the change of the vacuum degree.The advantages and disadvantages of several online and offline measurement methods are compared to prepare for the selection of reliable measurement methods and further improvements on the vacuum measurement accuracy.Then,after the analysis and comparison,two kinds of measuring methods,which are pulse magnetic control discharge and cold cathode gauge methods,are selected to collect the vacuum degree,arc distinguishing current data acquisition.The two measurement methods have the same principle,high accuracy and strong complementarity.And the BP algorithm of artificial neural network is used to predict and calculate the two data,also the trained neural network is used to test the results,and the test results match well with the target results.Again,using the maximum allowable leakage rate formula as the basis of the fusion calculation for the vacuum degree,but the problem of lack of accuracy must be properly solved.Therefore,from the artificial neural network theory,the optimization model of BP neural network is established in order to achieve the purpose of improving themeasurement accuracy.Taking the vacuum breaker curves provided by the manufacturer as a benchmark,the data collection is performed by the two methods,and the ultimate goal is to get the algorithm parameters of the vacuum degree with excellent accuracy.Finally,through the above research,a kind of vacuum state maintenance management system is proposed based on the protection devices,by which the new vacuum degree calculation method is realized.The currents on both sides of the circuit breaker contacts are real-time monitored based on the protection devices,therefore,using the vacuum current calculation formula to calculate the vacuum degree of vacuum arc extinguishing chamber in every fixed or breaking time,the new protective function and the state evaluation of the vacuum degree is realized.