Online DMD-based Kalman filter for current sensor fault-tolerant control of MMC-HVDC transmission systems

With the growing application of modular multilevel converter based high-voltage direct current transmission (MMC-HVDC), the sensor fault-tolerant capability in modular multilevel converters has become critical. This paper aims to boost the sensor fault-tolerant performance of the MMC-HVDC systems using advanced data- driven techniques. A novel online dynamic mode decomposition based Kalman filter (ODMDKF) is designed for fault detection and control reconfiguration. Besides, a modified dual-check fault detection module based on local outlier factor algorithm is proposed to reduce false alarm rate. Simulation studies are conducted on a modified IEEE 9-bus system with MMC-HVDC transmission lines. The results indicate that the proposed sensor fault-tolerant control method can ensure the continuous operation of the MMC-HVDC systems under the condition of three types of current sensor faults and its fault-tolerant capability is better than that of extended Kalman filter-based fault-tolerant control method.