Passive Fault-Tolerant Scheme for Double-Phase Open-Circuit Fault in <i>n</i> × 3 Phase SPMSM With Connected Neutral Point

Aiming at the defects of traditional fault-tolerant control and fault detection systems, a diagnosis-free passive fault-tolerant control (PFTC) scheme for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i>×3-phase surface-mounted permanent magnet synchronous motors (SPMSM) with connected neutral point is proposed. To reduce the cost, volume, and complexity of the driver, this article adopts a mono-inverter parallel drive for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i>×3-phase motors, which is a prerequisite for achieving passive fault tolerance. By combining the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i_d</i>=0 control strategy and field-oriented control technology of the traditional three-phase PMSMs, the self-healing capability can be realized after <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i>×3-phase SPMSMs experience double-phase open-circuit faults. Due to the proposed PFTC scheme not requiring the fault diagnosis process, the impact of misdiagnosis and diagnostic delays can be fundamentally avoided. In addition, there is no need to optimize the modulation strategy, motor model, or reference current before and after the fault, thus enabling smooth switching between different operating states. The proposed PFTC scheme can not only achieve seamless switching under multiple operating conditions but also be simple and easy to operate. The experimental results are carried out to verify the effectiveness and feasibility of the proposed method.