A Space Vector Pulse Width Modulation (SVPWM) control strategy is implemented for capacitor voltage balancing of Flying Capacitor (FC) based 4-level Neutral Point Clamped (NPC) inverter. This flying capacitor based 4-level NPC inverter is developed for medium voltage and high power applications. This system includes 6 power switching devices, 2 clamping diodes and 2 flying capacitors per leg. The flying capacitors ensure to operate inverter normally and all the switching devices share the voltage stresses in identical manner. Also it controls the voltage across each capacitor and maintained at Vdc/3 times of applied dc voltage. The proposed SVPWM method takes advantage of utilizing redundancy switching states to control and balance the voltage across the capacitor using nearest switching state vector selection method. Moreover, this system provides reduced total harmonic distortion (THD), and minimized voltage stress. The control technique is implemented without using any look-up tables or effective logic tables or trigonometric functions. The simulation and experimental results of this proposed verified are verified using Matlab-simulink and FPGA controller respectively.

中文翻译：

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基于飞电容的四电平NPC逆变器电容电压平衡的SVPWM控制策略

空间矢量脉宽调制 (SVPWM) 控制策略实现了基于飞电容 (FC) 的 4 电平中性点钳位 (NPC) 逆变器的电容器电压平衡。这种基于飞跨电容器的 4 电平 NPC 逆变器专为中压和高功率应用而开发。该系统包括 6 个电源开关器件、2 个钳位二极管和每条腿 2 个飞跨电容器。飞跨电容器确保逆变器正常运行，所有开关器件以相同的方式分担电压应力。它还控制每个电容器两端的电压并保持在 Vdc/3 倍的施加直流电压。提出的 SVPWM 方法利用冗余开关状态来控制和平衡电容器两端的电压，使用最近的开关状态矢量选择方法。而且，该系统降低了总谐波失真 (THD)，并最大限度地降低了电压应力。该控制技术是在不使用任何查找表或有效逻辑表或三角函数的情况下实现的。分别使用Matlab-simulink 和FPGA 控制器验证了该验证方案的仿真和实验结果。