Recent developments in multilevel inverters have provided impetus for their applications in the medium voltage renewable energy generation processes. This paper proposes an advanced pulse width modulation technique for a modular multilevel cascaded (MMC) inverter based grid integrated solar photovoltaic (PV) system. It offers lower total harmonic distortion (THD) and power losses compared to the existing modulation techniques. This paper shows the design and performance evaluation of the proposed technique using a 3-phase 5-level MMC inverter-based grid connected PV system. The proposed PWM technique offers 12.49% (without filter) and 0.96% (with filter) output line voltage THDs. It also offers 4.64% output current THD, which complies with the IEEE-519 standard for grid integration. Besides THD reduction, it also reduces the switching and conduction power losses of the MMC inverter. Lower losses may help to keep device temperature low, which is essential for power converters used in superconducting magnetic energy storage (SMES) systems. The simulation is performed in MATLAB/Simulink and the proposed technique is experimentally validated with a laboratory test platform.

中文翻译：

---

基于MMC逆变器的并网光伏系统的先进PWM技术


多电平逆变器的最新发展为其在中压可再生能源发电过程中的应用提供了动力。本文提出了一种先进的脉宽调制技术，用于基于模块化多级级联（MMC）逆变器的并网集成太阳能光伏（PV）系统。与现有的调制技术相比，它的总谐波失真 (THD) 和功率损耗更低。本文展示了使用基于三相 5 电平 MMC 逆变器的并网光伏系统的所提出技术的设计和性能评估。所提出的 PWM 技术提供 12.49%（无滤波器）和 0.96%（有滤波器）的输出线电压 THD。它还提供 4.64% 的输出电流 THD，符合电网集成的 IEEE-519 标准。除了降低 THD 之外，它还降低了 MMC 逆变器的开关和传导功率损耗。较低的损耗可能有助于保持器件温度较低，这对于超导磁能存储 (SMES) 系统中使用的电源转换器至关重要。仿真在 MATLAB/Simulink 中进行，并通过实验室测试平台对所提出的技术进行了实验验证。