On-line EMC Fault Diagnosis Technology Based On Fault Tree

With the development of modern electronic technology,the informationization process is accelerating,the electronic equipment is getting smaller and smaller,the degree of digitization and integration is continuously improving,the power and rate of high-power switch tubes of power electronic equipment are continuously increasing,and the electronic spectrum is occupied widely and densely.As well as the increasing sensitivity of electronic devices,electromagnetic compatibility issues have become more and more prominent,involving almost all electrical equipment and systems in various fields such as defense,military,industrial,and civilian.However,once the EMC problems such as EMI or test data exceed the standard occur in the electronic equipment,the traditional electromagnetic compatibility fault diagnosis process tends to be long-term,high-cost,and convenient,and an online electromagnetic compatibility fault diagnosis service platform that can provide rectification directions will greatly Reduce manpower and material resources and shorten the product rectification cycle.In this paper,for the electromagnetic compatibility problem of electronic equipment with excessive electromagnetic emission,the fault tree theory is used to decompose the fault elements of typical display and control electronic equipment.The display control principle and electromagnetic compatibility emission characteristics of the display and control equipment are studied and analyzed.Based on the three elements of electromagnetic compatibility,the electromagnetic compatibility fault tree model of the display and control equipment is established.The envelope feature extraction and interference source identification of the national military standard test data are realized.Using Internet technology to develop an online fault diagnosis platform based on fault tree that can dynamically correct the minimum cut set importance.The main research contents of this paper are as follows:Firstly,the explicit control electronic equipment is taken as the typical research object.The fault tree theory is used to decompose the fault features,and the basic components and display principles of different display and control electronic devices are studied.The common emission characteristics and similarities are summarized.We classify them into the three elements of electromagnetic compatibility,which are interference source,coupling path and sensitive equipment,and conduct electromagnetic compatibility radiation emission and conduction characteristics analysis of internal modules in display and control electronics.Then,according to the characteristics of national military standard test data,an envelope feature recognition matching algorithm is proposed.Firstly,the national military standard test data acquisition and test configuration requirements are introduced.Then,the obtained test data is first subjected to data pre-processing to remove noise,and the envelope features are extracted.Then,the extracted envelope features are analyzed,and according to the characteristics of the envelope,the frequency offset processing and the interpolation calculation are performed,and then the Pearson similarity calculation is performed with the corresponding fault tree bottom event fault template stored in the database.The obtained correlation coefficient dynamically modifies the failure probability of the event at the bottom of the fault tree by the corresponding weight,and finally calculates the minimum cut set importance.Finally,using Internet technology to implement a platform allows users to submit national military standard test data online,use relevant algorithms for data processing,obtain envelope characteristics of test data and perform feature identification,and finally obtain a minimum cut set importance table.Thereby achieving online electromagnetic compatibility fault diagnosis.