Multi-vector Model Predictive Direct Power Control for Fault-tolerant Bidirectional AC/DC Converter

摘要

So as to reduce the current harmonics and power ripple after bidirectional AC/DC converter bridge arm fault, a multi-vector model predictive fault-tolerant control method is proposed. First, the system of bidirectional AC/DC converter with a bridge arm fault is reconstructed. Then the operation mechanism of fault-tolerant converter structure and the relationship of voltage vectors are clarified. Second, the power prediction model under the converter fault-tolerant operation mode is established. Multiple voltage vectors are used in a switching cycle. The new synthetic vector is used to track the optimal vector. The switching order of each vector is fixed to realize switching frequency concentrate. Third, the simulation model is built. The results show that the bidirectional AC/DC converter can operate fault-tolerant operation after the bridge arm failure under the control strategy proposed and the output current harmonics and power ripples are reduced. The system has good steady-state and dynamic performance.