随着我国双碳目标的稳步推进，光伏(photovoltaic, PV)发电占比迅速攀升，而PV受电力电子变换器的拓扑结构、输出电能质量及其工作效率的影响较大。基于此，本文提出了一种基于改进H桥多电平逆变器(improved H-bridge multilevel inverter, IHBMLI)的光伏发电系统(PV power conversion system, PPCS)，该发电系统可实现太阳能的高效利用，通过五电平输出电压可极大降低总谐波失真，低开关频率降低了系统总损耗，从而提高了配电系统的电能质量。此外，本文还设计了一种单输入多输出(single input multiple output, SEPIC)的变换器来跟踪PV的最大功率点，以实现与直流源的隔离。最后，通过仿真与实验，验证了所提逆变器的性能，结果表明，该发电系统可通过电网的无功支撑和谐波抑制来实现功率因数校正，并有效提升变换器在输出电能质量和效率等方面的性能。
With the steady progress of China's dual carbon goal, the proportion of photovoltaic (PV) power generation is rising rapidly, while PV is greatly affected by the topology of power electronic converter, output power quality and working efficiency. Based on this, this paper proposes a PV power Conversion System (PPCS) based on IHBMLI (Improved H-Bridge Multilevel Inverter). The power generation system can realize the efficient utilization of solar energy, the total harmonic distortion can be greatly reduced through the five-level output voltage, and the low switching frequency reduces the total loss of the system, so as to improve the power quality of the distribution system. In addition, a single input multiple output (SEPIC) converter is designed to track the MAXIMUM power point of PV to achieve isolation from dc source. Finally, the performance of the proposed inverter is verified by simulation and experiment. The results show that the power factor correction can be realized through the reactive power support and harmonic suppression of the power grid, and the performance of the converter in terms of output power quality and efficiency can be effectively improved.