微逆变器交流侧泛Buck-boost功率解耦技术研究

针对微逆变器二倍频功率扰动问题，提出了一种交流侧泛Buck-boost功率解耦技术。设计的四种能实现能量双向流动的解耦电路均并联在逆变器交流侧，不同拓扑都可等效工作在Buck、Boost或Buck-boost的模式中。从拓扑结构、工作模式及解耦性能三方面分析了设计的四个解耦电路，以及每种拓扑抑制二次谐波的能力。讨论了脉冲能量缓冲的计算方法。仿真结果表明，三模态六开关Buck-boost功率解耦电路抑制电压二次谐波效果最优，单模态六开关Buck-boost功率解耦电路抑制电流二次谐波效果最优。泛Buck-boost功率解耦技术可以在不依赖母线大电压情况下，大幅降低解耦电容容值，实现无电解电容，提高微逆变器可靠性并延长其使用寿命。

Research on pan buck-boost power decoupling technology on the AC side of a micro-inverter

To tackle the double power disturbance problem of a micro-inverter, an AC-side pan Buck-boost power decoupling technique is proposed. Four decoupling circuits designed to achieve bidirectional flow of energy are connected in parallel to the AC side of the inverter. Different topologies can work in Buck, Boost or Buck-boost mode. The four decoupling circuits designed are analyzed in terms of topology, working mode and decoupling performance on the ability of each topology to suppress the second harmonic. The calculation method of a pulse energy buffer is discussed. The simulation results show that the three-mode six-switch Buck-boost power decoupling circuit suppresses the voltage second harmonic effect optimally, and the single-mode six-switch Buck-boost power decoupling circuit suppresses the current second harmonic effect optimally. The pan Buck-boost decoupling technology can greatly reduce the decoupling capacitance value without relying on a large busbar voltage, and realize the electroless capacitor, and improve the reliability of the micro-inverter and prolong its service life.This work is supported by National Natural Science Foundation of China (No. 51467006).