Research On Data Acquisition And Data Fusion In Expert System Of Vacuum Measurement

The vacuum level in a vacuum interrupter is an important technology parameter that ensures the functions of insulation and arc suppressing of vacuum switch. When vacuum switch is in service, if a certain threshold of vacuum level has been surpassed in the vacuum interrupter, it will lead to the vacuum switch cann't work normally; a great harm is caused for the safe operation of power system. In this paper, the theory of data acquisition and data fusion is applied to solve signal amplification and acquisition of vacuum level in the expert system of vacuum measurement, and do data fusion for measured values of different vacuum measurement methods, which can constitute a part of intelligent expert system of vacuum measurement.Above all, through research on vacuum measurement methods, the pulsed magnetron-discharge and shielding potential method are selected to test and study. According to practical requirements of selection parameters of data acquisition card, and after the parameter calculation, data acquisition card USB2812 is selected for signal acquisition. Because the current signal corresponding to vacuum measurement isμA class, signal amplification circuit is designed and simulated, the signal which comes up to analog input range of data acquisition card is obtained.Secondly, because of various disturbances in the vacuum measurement, the blunder errors are often caused in the measurement process, so in this paper the consistency test is done for each kind of vacuum measurement by using distribution method, blunder errors are excluded, and then adaptive weighted algorithm is applied to process data for two kinds of vacuum measurement methods, measured values of two kinds of vacuum measurement methods are substituted into to calculate, thus more effective fusion values of vacuum level can been obtained.Finally, combining with visual programming environment, two-channel data acquisition interface is built which based on LabVIEW. In this procedure, signal acquisition and data storage can be completed through designing acquisition experiment of voltage signal, so the procedure is proved to be feasible. Programme for the proposed data fusion algorithm in LabVIEW, input measured values to verify and compare with the results of calculation, the results are consistent, and so it is achieved to intelligent data processing, which can provide theoretical support to establish the dynamic database of expert system. With the gradual improvement of hardware and software, an intelligent expert system of vacuum measurement will be realized sooner or later.