Research On Fault Diagnosis Method Of Traction Transformer Based On Fractal Theory

With the rapid development of China's electrified railway,the safe operation of railway gets more and more attention.As the function of voltage class transformation and power distribution,the traction transformer is an important part of traction power supply system,and its safe and reliable operation also is related to the security and stability of the electrified railway.The fault of traction transformer will cause huge loss and chaos.In order to ensure the safe and economic operation of the railway transportation,the fault type of traction transformer must be determined timely and accurately,and take measures to solve the problem.By reading a large of domestic and foreign literature on fault diagnosis as well as investigating in some substations,incorporating with the development of all kinds of theories in nonlinear subjects,the application of fractal on fault diagnosis is studied.Basing on fractal theory,a fault type diagnosis method about traction transformer was proposed.Firstly,the status quo and meaning of fault diagnosis was described,and the internal structure and function of traction transformer were introduced in the paper.And the origin and application of fractal on a variety of fault diagnosis were reviewed,and the waveform characteristics of the sampling signal of the fault current in transformer were analyzed by adopting the fractal theory then,judging the fault type by comparing the fractal box dimensions of the current sampling signal before and after the fault.Which was applied to traction transformer microcomputer protection.Using the software MATLAB/Simulink,the traction transformer modules were built and simulated and the current signals were extracted.The box dimensions were calculated by the use of fractal tool Fraclab and programming respectively.The experiment results prove that the method can ensure the fault type rapidly and accurately.At last,by using of the client development tool Eclipse,a portable traction transformer fault diagnosis system which is based on fractal theory on the platform of Android was designed.The system had three modules mainly: user management,fault diagnosis and database management.The feasibility and effectiveness of the portable traction transformer fault diagnosis system was verified in the paper,and the system had the advantages of man-machine interactive,high stability and the stronger versatility and so on.