Research On On-Line Diagnosis System For Locomotive Electronic Control Cabinet

The locomotives in China are being developed in the high-speed and heavily loaded direction, so higher demand about dependability and security for the locomotive has been put forward. The operating state of the locomotive is very important to security of the whole railway system. It is very meaningful to monitor and diagnose the important parts of locomotive in real time. The electronic control cabinet is an important part of electric locomotive. So researching the scheme and diagnostic method about on-line diagnosis system for locomotive electronic control cabinet is the main content of this thesis.After studying the composing and the theory of the locomotive electronic control cabinet deeply, comparing various kinds of fault diagnosis method, the author decides to use the fault diagnosis method based on graph theory. In the paper, the method based on fault propagation digraph is introduced in detail. After researching how to acquire the operating state data, taking SS4G locomotive as an example, the author builds input-output model of each part of the electronic control cabinet according to the model of traction motor and the model of three sections rectification bridge, and divides the electronic control cabinet into 4 statuses. The four statuses are A traction status, B traction status, A brake status and B brake status. Each status can be set up fault propagation digraph, adjacent matrix, attainable matrix and level structuring graph. A fault location method based on falut propagation matrix is introduced at the end of thesis.