Abstract Modular multilevel converter (MMC) is a promising highly modular converter. However, the problems of voltage balancing control strategies in the MMC should be studied in detail. In order to improve the effect of voltage balancing, reduce the amount of calculation, and simplify the switch control of the submodules (SMs), this paper proposes a method that using a matrix to control the switch signals of the SMs based on the nearest level control (NLC) method. First, by sorting the capacitor voltage of the SMs, the required SMs are selected according to the NLC method. Since each arm contains N SMs, it is assumed that each SM corresponds to an N-dimensional column vector. The nth element of column vector corresponding to the nth SM is 1, and the others are 0. Then, the column vectors corresponding to all the SMs are used to form an N × N identity matrix. Secondly, assuming that the identity matrix is E, when the i-th SM is selected, a column vector corresponding to it is selected, such as a(i)= E(:, i), where E(:, i) is the i -th column of E; then, the sum of a(i) is calculated to obtain the switch signals of all SMs of each arm, so as to control the SMs. Finally, the simulation was set up on the Matlab/Simulink, and the proposed method is studied and analyzed.

中文翻译：

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一种模块化多电平转换器的电容电压平衡控制策略

摘要 模块化多电平转换器(MMC)是一种很有前途的高度模块化的转换器。然而，需要详细研究MMC中电压平衡控制策略的问题。为了提高电压均衡的效果，减少计算量，简化子模块（SM）的开关控制，本文提出了一种基于最近电平的利用矩阵控制子模块开关信号的方法。控制 (NLC) 方法。首先，通过对 SM 的电容电压进行排序，根据 NLC 方法选择所需的 SM。由于每个臂包含 N 个 SM，因此假设每个 SM 对应一个 N 维列向量。第n个SM对应的列向量的第n个元素为1，其余为0。那么，所有SM对应的列向量被用来形成一个N×N的单位矩阵。Secondly, assuming that the identity matrix is E, when the i-th SM is selected, a column vector corresponding to it is selected, such as a(i)= E(:, i), where E(:, i) is E 的第 i 列；然后计算a(i)之和，得到各臂所有SM的开关信号，从而控制SM。最后，在Matlab/Simulink上建立了仿真，并对所提出的方法进行了研究和分析。