Ebrahimabad Reza Choupan, Nazarpour Daryoush, Golshannavaz Sajjad, Bolandi Tohid Ghanizadeh
Electrical and Computer Engineering Department, Urmia University, 11km SERO Road, Urmia, Iran.
ISA Trans. 2023 Dec;143:707-722. doi: 10.1016/j.isatra.2023.09.003. Epub 2023 Sep 5.
In the conventional multilevel inverters, occurrence of a fault in one or more power switches can cause abnormal changes in the output waveforms. Besides, increasing the applied power switches results to an increase in the possibility of fault on the power switches. Accordingly, providing a comprehensive structure with high fault-tolerant capability is one of the vital requirements and critical challenges. To tackle these issues, this study first presents and explores a new basic unit and staircase module (SM) and then extends and optimizes it to yield a reconfigurable multi-level inverter (MLI) with more levels and different goals. The proposed MLI can continue to operate when open-circuit faults in switches. This advantage of the proposed structure is achieved without any redundant legs or switches. For further investigation, a comparison is made in terms of the number of power switches, drivers, dc sources, and reliability between the proposed and similar structures. To control the output voltage levels, the strategy of fundamental frequency switching triggers the configured topology. The carrier signals are reconfigured under fault conditions based on levels to be generated by bypassing the faulted switch. The validity of the established MLI with its fault-tolerant capability is certified through both computer simulations using the MATLAB/Simulink platform and laboratory prototype implementations.
在传统的多电平逆变器中，一个或多个功率开关出现故障会导致输出波形发生异常变化。此外，增加所使用的功率开关会导致功率开关出现故障的可能性增加。因此，提供一种具有高容错能力的综合结构是至关重要的要求和关键挑战之一。为了解决这些问题，本研究首先提出并探索了一种新的基本单元和阶梯模块（SM），然后对其进行扩展和优化，以产生具有更多电平且目标不同的可重构多电平逆变器（MLI）。所提出的MLI在开关出现开路故障时能够继续运行。所提出结构的这一优点是在没有任何冗余桥臂或开关的情况下实现的。为了进一步研究，对所提出的结构与类似结构在功率开关数量、驱动器、直流电源和可靠性方面进行了比较。为了控制输出电压电平，基频开关策略触发配置的拓扑结构。在故障条件下，根据要生成的电平重新配置载波信号，以绕过故障开关。通过使用MATLAB/Simulink平台进行计算机仿真和实验室原型实现，验证了所建立的具有容错能力的MLI的有效性。
