Inverters as one of the most important elements of power systems have been profoundly developed in recent decades and their performance has attracted researches in control and structure point of view. In this study, a novel structure based on the switch-diode-source cell is proposed for a multilevel converter that is capable of bidirectional feeding. The proposed structure is presented for symmetrical mode and the number of power electronic devices is decreased in comparison with similar works. Considering recent proposed symmetrical structures, the proposed structure has the superior condition in terms of semiconductor switches and drivers count as well as switching loss. Also, total blocked voltage (TBV) of the proposed converter is compared with conventional and novel symmetrical converters. Then, switch costs of the proposed converter are compared with the structure that its TBV is the lowest. The performance of the proposed symmetrical seven-level converter is analysed and simulated in MATLAB/Simulink for both PWM and selective harmonic elimination switching methods. Not only the results are desirable, but also the experimental results of laboratory prototype validate the simulation results.

中文翻译：

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基于开关二极管源单元的对称双向多电平逆变器的开关数减少结构

逆变器作为电力系统最重要的组成部分之一，在近几十年来得到了长足的发展，其性能引起了人们对控制和结构观点的研究。在这项研究中，提出了一种基于开关二极管源单元的新型结构，用于能够双向馈电的多电平转换器。提出的结构用于对称模式，与类似的工作相比，减少了电力电子设备的数量。考虑到最近提出的对称结构，提出的结构在半导体开关和驱动器数量以及开关损耗方面具有优越的条件。而且，将所提出的转换器的总阻断电压（TBV）与常规和新颖的对称转换器进行了比较。然后，将拟议转换器的开关成本与其TBV最低的结构进行了比较。在MATLAB / Simulink中针对PWM和选择性谐波消除开关方法对所提出的对称七电平转换器的性能进行了分析和仿真。不仅结果令人满意，而且实验室原型的实验结果也验证了模拟结果。