With the development of ship integrated electric propulsion system,the increase power quality of ship electrical equipment and power density requirements,the twelve phase synchronous generator rectifier system with smaller voltage ripple,higher power density and excellent dynamic performance characteristics,is becoming a competitive generator system in ship integrated power system field and gradually replace the traditional DC power supply system has been widely used.The safety and stable operation of the twelve phase synchronous rectification power generation system has great significance to ensure the quality of electric power and the safety of the crew.It has practical significance to study the fault diagnosis method of the power system.Firstly,this paper based on the mathematical model of MATLAB/Simulink,analyzed normal simulation model and mathematical model of the twelve phase synchronous rectifier power system.On this basis,analyzed the generator’s typical faults mechanism,and modelled the typical faults,included the typical fault of rectifier open circuit fault,different stator winding turn to turn short circuit fault,fault current generator,and according to the harmonic characteristics of fault generated and normal operation state to distinguished fault feature extraction.Secondly,this paper made the overcurrent as an example,analyzed possible causes of generator current phenomenon,made a generator overcurrent’s fuzzy fault tree based on T-S,researched fault diagnosis method based on T-S fuzzy model.A method is proposed to replace the bottom event’s failure degree with bottom event’s feature degree when bottom event’s failure degree is difficult to obtain.Studied on the T-S fault tree model of overcurrent,with the feature of stator winding turn to turn short circuit as the bottom event,through the fault state of bottom event and fuzzy probability,estimate the possibility of the overcurrent phenomenon,verified the effectiveness of the diagnosis method.Moreover,based on the principle of fuzzy pattern recognition,the fault diagnosis method is studied in the case that the fault mode and fault symptom couldn’t be one-to-one correspondence.In this paper,in order to fit the different levels of power generators,obtained fitting functions which are suitable to the different load condition of the fault symptoms,suitable for all kinds of load conditions of twelve phase synchronous generator rectifier fault diagnosis,avoided wrong judgment caused by the harmonic content changes due to different levels of power generator,improved the diagnostic accuracy and applicability.Finally,based on LabVIEW and the function of LabVIEW to access the database,realized on-line fault diagnosis of twelve phase synchronous generator,and the storage and query of diagnostic results,verified the effectiveness of the method,that function fitting of feature vectors method combined with fuzzy pattern recognition algorithm,used in fault diagnosis. |