For the five-level active neutral point clamped (5L-ANPC) converter, the coupling problem between the DC-link capacitor voltages and flying-capacitor (FC) voltages will increase the capacitor voltage fluctuations. The capacitor voltage fluctuations and current harmonics of the space vector pulse width modulation (SVPWM) are less than those of the sinusoidal pulse width modulation (SPWM), because the maximum linear modulation index of the SVPWM is higher than that of the SPWM. However, SVPWM has difficulty in realizing the decoupling control of the capacitor voltages, and the computation complexity of SVPWM is much higher than that of SPWM. This paper proposes a third harmonic injection modulation algorithm for the 5L-ANPC converter. The proposed algorithm injects the third harmonic into the modulation waves of SPWM, which makes the maximum linear modulation index of SPWM the same as that of SVPWM, to reduce the capacitor voltage fluctuations and current harmonics. The calculation of the third harmonic only requires a standard sorting algorithm and a simple linear operation; thus, it is easy to implement. Based on the third harmonic injection modulation algorithm, two variables are introduced to control the neutral point (NP) current and the FC current. And the two variables are used to feedforward compensate the modulation waves, realizing the decoupling control of the capacitor voltages. The proposed decoupling control method can further reduce the capacitor voltage fluctuations. Experimental results are presented to verify the validity of the proposed algorithm.

中文翻译：

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基于三次谐波注入调制的五电平有源中点钳位变换器电容电压前馈解耦控制

对于五电平有源中性点钳位（5L-ANPC）转换器，直流母线电容器电压与飞跨电容器（FC）电压之间的耦合问题将增加电容器电压波动。空间矢量脉宽调制（SVPWM）的电容电压波动和电流谐波小于正弦脉宽调制（SPWM），因为SVPWM的最大线性调制指数高于SPWM。但SVPWM难以实现电容电压的去耦控制，计算复杂度远高于SPWM。本文提出了一种用于 5L-ANPC 转换器的三次谐波注入调制算法。所提出的算法将三次谐波注入到 SPWM 的调制波中，这使得SPWM的最大线性调制指数与SVPWM相同，以减少电容器电压波动和电流谐波。三次谐波的计算只需要标准的排序算法和简单的线性运算；因此，它易于实施。基于三次谐波注入调制算法，引入两个变量来控制中性点（NP）电流和FC电流。并利用这两个变量对调制波进行前馈补偿，实现电容电压的解耦控制。所提出的去耦控制方法可以进一步降低电容器电压波动。实验结果验证了所提出算法的有效性。以减少电容器电压波动和电流谐波。三次谐波的计算只需要标准的排序算法和简单的线性运算；因此，它易于实施。基于三次谐波注入调制算法，引入两个变量来控制中性点（NP）电流和FC电流。并利用这两个变量对调制波进行前馈补偿，实现电容电压的解耦控制。所提出的去耦控制方法可以进一步降低电容器电压波动。实验结果验证了所提出算法的有效性。以减少电容器电压波动和电流谐波。三次谐波的计算只需要标准的排序算法和简单的线性运算；因此，它易于实施。基于三次谐波注入调制算法，引入两个变量来控制中性点（NP）电流和FC电流。并利用这两个变量对调制波进行前馈补偿，实现电容电压的解耦控制。所提出的去耦控制方法可以进一步降低电容器电压波动。实验结果验证了所提出算法的有效性。基于三次谐波注入调制算法，引入两个变量来控制中性点（NP）电流和FC电流。并利用这两个变量对调制波进行前馈补偿，实现电容电压的解耦控制。所提出的去耦控制方法可以进一步降低电容器电压波动。实验结果验证了所提出算法的有效性。基于三次谐波注入调制算法，引入两个变量来控制中性点（NP）电流和FC电流。并利用这两个变量对调制波进行前馈补偿，实现电容电压的解耦控制。所提出的去耦控制方法可以进一步降低电容器电压波动。实验结果验证了所提出算法的有效性。