Diagnosis method for full open circuit fault modes in dual three-phase permanent magnet synchronous motor driver

Accurate identification and diagnosis of open-circuit faults in the driver can effectively prevent serious accidents caused by further deterioration of faults and is also a prerequisite for implementing proper fault-tolerant control strategies. The types of open-circuit faults in the driver include the single power switch fault, multiple power switches fault, and mixed fault of power switch and phase. The diagnosis method of fully open-circuit fault modes that can identify all the above types was proposed. Firstly, a direct coupling analysis model was constructed that can consider many non-ideal factors and the interaction between the motor and the driver to facilitate the simulation of multiple fault scenarios and improve calculation precision of the theoretical model, and accuracy and effectiveness of the model was verified through experiments. Secondly, the fault factors and auxiliary fault factors were extracted from the sub-frame currents in vector space decomposition and winding phase currents, and the diagnosis method based on the two fault factors was proposed, and the threshold range and usage of the two fault factors were clarified. Finally, six different types of open-circuit faults were identified and diagnosed, by relying on the validated direct coupling analysis model, proving the validity of the proposed method. © 2024 Editorial Department of Electric Machines and Control. All rights reserved.