Fault-Tolerant Operation of Medium Voltage PMSM Drive Systems Under Open-Switch Faults

Abstract

Medium voltage (MV) drive systems are extensively used in some critical industrial applications such as mining, marine operations, oil processing, and large-scale production. MV drives which are based on voltage source inverters remain vulnerable to semiconductor open-switch faults. Permanent Magnet Synchronous Motor (PMSM) drives are adopted largely by industry for their dynamic response, high efficiency, and compact design. This paper embeds a fault-tolerant control strategy that can be integrated into inverter-based MV drives. The system can enhance the post-fault drivability of MV PMSM drive systems under open-switch faults. The suggested methods consist of three main components. The first one is a comprehensive mathematical analysis of the post-fault voltage vector space, and it leads to a reallocation strategy for the vector acting time calculated by space vector pulse width modulation (SVPWM). Secondly, a fault-aware current prediction model is developed to make stable and smooth control mode transition between healthy and faulted conditions. Experimental and simulation results demonstrate that the proposed approach improves the current tracking accuracy and enhances operational robustness.