Fault Diagnosis of Current Sensors for Dual Three-Phase PM Machines Based on Harmonic Current

For electrified transportation systems, dual three-phase permanent magnet synchronous motors (DTP-PMSMs) feature a higher capability of the fault-tolerant compared with the three-phase ones. However, DTP-PMSMs requires additional current sensors, leading to a higher possibility of current sensor failures. In this paper, a novel fault diagnosis strategy of current sensors for DTP-PMSM based on harmonic current is proposed. First, the characteristics and diagnosis mechanisms of current sensor faults are thoroughly analyzed based on the internal relationship between the x-y currents and the $o_{1}-o_{2}$ currents under faulty conditions. To enhance the algorithm’s speed without compromising robustness, a flexible threshold setting method is adopted. The effectiveness and speed of the proposed fault diagnosis algorithm are verified through experiments involving various types of current sensor faults.