A Combined Fault-Tolerant and Model Predictive Control for Dual-Terminal Cascaded Five-Level Open-End Winding Induction Motor

摘要

The power converter is a vulnerable part of the drive system. The dual three-level inverter (DTI) reduces the DC bus specification, improves the output waveform, and is widely used in medium-voltage and high-power applications, which simultaneously increases the switching frequency of the inverter switching device. Therefore, switching device become the component with the highest frequency of failure in the drive system. In this paper, a model predictive current fault-tolerant control strategy is proposed to realize the open-circuit fault of a bridge arm and single turning tube of DTI system. In cost function, the stator current is used as the tracking target, and the constraint term of the mid-point potential balance is introduced to adjust DC bus voltage, zero-sequence loop is eliminated at the same time. At the time of a bridge arm or single turning tube fails in one inverter, the remaining zero common-mode vectors are selected offline this measure eliminates the zero-sequence current and dramatically reduces the calculation delay. Simulink results validate the analysis of proposed scheme.