计及中点电位平衡ANPC三电平逆变器容错控制

Fault Tolerant Control Considering Neutral-point Potential Balancing for ANPC Three-level Inverter

针对有源中点箝位型(ANPC)三电平逆变器开路故障容错控制以及容错运行时中点电位不平衡问题,基于自愈型ANPC(SF-ANPC)拓扑提出改进型拓扑结构,并根据直流侧等效数学模型提出一种基于扩张状态观测器(ESO)的容错运行时中点电位平衡控制策略。分析改进型ANPC拓扑逆变器在不同开路故障时的容错控制方案,由仿真和实验分析改进型ANPC拓扑逆变器的容错控制以及容错运行中点电位平衡控制效果。结果表明,该容错控制方案能够在逆变器故障容错控制后保证逆变器稳定工作,同时容错运行时中点电位波动得以控制,验证了改进型拓扑结构及容错控制策略的有效性和可行性,逆变器可靠性得到了提升。

Neutral-point potential unbalancing and fault-tolerant control is proposed for the active neutral point clamped(ANPC)three-level inverter,an improved ANPC topology based on the self-healing ANPC(SF-ANPC)topology is proposed,and aiming to neutral-point potential balance,a control strategy is proposed based on extended state observer(ESO)under the equivalent circuit model of DC side.Analyzing the fault-tolerant of different open-circuit fault and the corresponding control are put forward under the improved ANPC topology,fault-tolerant control and neutralpoint potential balancing control are analyzed by simulation and experiment.The results show that fault-tolerant control strategies can ensure the inverter continue to be operated stably,meanwhile,the fluctuation of neutral-point potential can be suppressed,the simulation and experiment prove the effectiveness and feasibility of the proposed strategy,the inverter reliability has been improved.