Research On Fault Diagnosis Technology Of Power Electronic Circuits Based On Bond Graph Model

Power electronic devices have been widely used in military and civilian fields, and its securityand reliability directly affect the function and safety of power supply equipments. Power electroniccircuits are the main parts of power electronic devices. In order to increase the reliability and theability of fault diagnosis and isolation (FDI) of power electronic devices, analysising fault diagnosistheories and methods on power electronic circuits, achieving real-time fault diagnosis and location areof great significance and engineering application value.This thesis mainly studies modeling and FDI approaches of power electronic circuits based onbond graph method. The main contents of the thesis are as followed.（1）The principle, causality and characteristic equations of bond graph are stated. The modelingmethods of switched bond graph are summarized and analyzed. And the environment and function ofbond graph modeling software20-sim also are introduced.（2）One switched bond graph element is presented with invariable causality. Power electroniccircuits modeling technologies are detailly analyzed based on bond graph. Adding auxiliary elementsolve algebraic loop and causality conflict in bond graph modeling. Buck cicuits and three phaseinverters are considered as the illustrative examples and the case study shows the modeling method iseffective.（3）Global analytical redundancy relation is presented in FDI application of power electroniccircuits and a fault diagnosis framework based on bond graph model is also proposed. The parametricfault of Buck circuit and the open fault of thrase inverter are verified, and the experiment result showsthe effectiveness of the proposed fault diagnosis framework.（4）The qualitative fault diagnosis principle based on bond graph mode is analysized and theprocess of time causal graph and fault trees are also studied. The mechanical and electrical system andthree-phase inverter are illustrtrated as example to verify the presented approach is effective.