Abstract This paper presents a nearest-level-equivalent space vector modulation (SVM) algorithm for three-phase multilevel converters. The proposed algorithm provides a simple approach to obtain three modulation vectors online based on basic vectors. In addition, the principle of nearest-level modulation (NLM) is applied in the proposed SVM to make its superior performance to the generalized SVM algorithms, which present: (1) Merely one modulation vertex need to be detected and three-phase duty cycles are obtained. Therefore, the unbalanced voltages of inner cell of neutral-point-clamped cascaded multilevel converter (NPC-CMC) can be addressed; (2) Redundant and optimized switching sequences are automatically generated to minimize the number of switching transition; (3) Different modulation modes can be flexibly chosen to optimize the harmonic benefit. The proposed SVM scheme is independent of level numbers and finally verified by simulation and experimental results.

中文翻译：

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一种快速灵活的三相多电平变换器最近电平等效空间矢量调制算法

摘要 本文提出了一种用于三相多电平转换器的最近电平等效空间矢量调制（SVM）算法。所提出的算法提供了一种基于基本向量在线获取三个调制向量的简单方法。此外，在所提出的 SVM 中应用了最近电平调制（NLM）的原理，使其性能优于广义 SVM 算法，其表现出：（1）只需检测一个调制顶点和三相占空比获得。因此，可以解决中性点钳位级联多电平转换器（NPC-CMC）内部单元的电压不平衡问题；(2) 自动生成冗余优化的切换序列，尽量减少切换转换次数；(3)可以灵活选择不同的调制方式，优化谐波效益。所提出的 SVM 方案与层数无关，最终通过仿真和实验结果进行验证。