一种具有自修复功能的多电平变换器拓朴

从提高复杂多电平变换器的可靠性出发，提出了一种具有类似生物系统自修复功能的多电平变换器拓扑。电路拓扑工作原理的分析结果表明，该拓扑在正常工作情况下所有开关管均承受单位电平的电压应力，并且以较少的飞跨电容实现每个电压电平的自动平衡。该拓扑不需要任何复杂的中点电位平衡电路或控制措施。文中详细分析了电路中开关管故障对多电平变换器系统运行和器件电压应力的影响。分析结果表明，当某些开关管出现短路或断路故障时，通过简单的软件重构改变驱动信号，利用冗余开关状态组合，电路仍能得到所有电平的正常输出和直流侧电容的电压自平衡，真正实现了原有功能的自修复。整个多电平变换器系统的可靠性由此提高。文中以五电平变换器为例进行了分析研究，并通过仿真实验进行验证。

A MULTILEVEL CONVERTER TOPOLOGY WITH SELF-REPAIR ABILITY

A novel multilevel converter topology with self-repair ability is proposed in this paper by which some biological systems are usually characterized to enhance the reliability of complex multilevel converters. In the presented multilevel converter topology each dc voltage level con be balanced automatically without any additional neutral-point-potential balancing circuit or control, and also one voltage level stress for can be maintained each power switch .This paper focuses on device failure and the corresponding impact on the operating conditions and resulting stresses. In case of some switches short or open faults, the topology will exhibits self-repair ability, i.e., it can still output all expected voltage levels and keep each dc link capacitor self voltage balancing via simple control software re-configuration and changing drive signals based on the redundant switching states. A single-phase five-level inverter is considered and the validity is proven by simulations and experiment.