Modulation wave hybrid control strategy for expanding stable operation range of cascade grid-connected inverter

The invention discloses a modulated wave hybrid control strategy for expanding the stable operation range of a cascade grid-connected inverter, and belongs to the field of electrical engineering. The invention aims to solve the problem of power mismatching caused by uneven illumination of each H-bridge unit photovoltaic module of the single-phase cascade grid-connected inverter. The method comprises the steps of phase-locked control, direct-current bus voltage control, grid-connected current control, modulation wave generation control and carrier phase-shift modulation. Compared with the prior art, the stable operation range of the cascade grid-connected inverter is expanded, and the capacity of the cascade grid-connected inverter for coping with uneven illumination on the direct current side is improved. 本发明公开了一种扩大级联并网逆变器稳定运行范围的调制波混合控制策略，属于电气工程领域。本发明的目的是解决由于单相级联并网逆变器各H桥单元光伏组件光照不均导致的功率不匹配问题。步骤包括锁相控制、直流母线电压控制、并网电流控制、调制波生成控制和载波移相调制。相比现有技术，本发明扩大了级联并网逆变器的稳定运行范围，提高了级联并网逆变器应对直流侧光照不均的能力。