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The safety and reliability of inverters play a significant role in stable power electronic system operations. Considering a railway vehicle air-conditioning inverter as a case study, this paper presents a generic open-circuit fault diagnosis method that can be applied to various inverter and control schemes. First, a detailed model of three-phase output currents under both normal and fault status is derived, and then the concept of space trajectory is introduced based on the three-phase output currents. The open-circuit faults of the inverter lead to output phase current distortion. Therefore, different types of faults have different space trajectories, and the corresponding shape of the space trajectory is considered to be a fault feature. Then, the fault is located by the direction vector and center-of-mass coordinate. The effectiveness and reliability of the diagnosis method are verified and analyzed using a hardware-in-the-loop test platform. [ABSTRACT FROM AUTHOR]

This paper proposes a new method based on the comprehensive transition criteria of speed, flux position, and voltage vector to solve the transition problem in hybrid direct torque control. In addition, the control angle is introduced that is adjusted by the smoothness and rapidity. Peak current, flux distortion, and torque ripple can be significantly reduced by the proposed method. [ABSTRACT FROM AUTHOR]

A noninvasive diagnosis method for open-circuit faults of a locomotive inverter is proposed. Two different voltage transients are defined according to output voltage values, and the ratio of them is used for diagnosis. Faults can be detected immediately when they occur. The method and its robustness are verified on dSPACE. [ABSTRACT FROM AUTHOR]

The instability of the switching frequency in an inverter with hysteresis current results in a high failure rate of the power switching components of the inverter. To address this hurdle, a low-cost fault-tolerant control strategy is proposed in this paper to effectively correct the faults. [ABSTRACT FROM AUTHOR]