A Diagnostic Method for Inverter Faults in Aviation VSCF System Based on Voltage Vector Diagram and Crossing Phase Reconfiguration

The inverter of variable speed constant frequency system is the indispensable equipment to maintain the normal operation of avionics system. However, the open-circuit fault diagnosis of aeronautical complex intermediate-frequency inverter is always a thorny problem. To solve this problem, this paper creatively proposes a fault diagnosis algorithm. First, the average model is utilized to analyze the voltage and determine the fault phase. Secondly, the voltage vector diagram is attracted according to the Concordia transformer. According to the different centroid positions and radius ratios of the voltage vector diagram, the number of fault IGBTs and fault IGBT candidate pairs can be determined. Then, a new virtual phase is constructed according to the proposed reconfiguration method. Meanwhile, the average model is used to analyze the virtual phase. Finally, combining the analysis result of voltage vector diagram and virtual phase, the fault IGBT can be determined. Compared with the existing methods, the proposed method not only solves the problem that the fault characteristics of the aviation inverter are not obvious due to the complex structure, but also realizes the open-circuit fault diagnosis of the composite intermediate-frequency inverter without adding additional sensors. At last, the proposed method is verified to be feasible.