一种具有解耦能力的反激式电流型逆变器

A single stage photovoltaic inverter with reactive power compensation and no electrolytic capacitance

单级微型逆变器因结构简单、成本低而广泛应用于光伏发电。但存在的二倍工频脉动势必造成光伏侧电压、电流较大波动,导致最大功率点跟踪(Maximum Power Point Tracking, MPPT)控制器设计困难。现有采用电解电容的无源解耦方案导致逆变器使用寿命缩短。对此,文章提出一种具有功率解耦能力的反激电流型微型逆变器。该拓扑通过创造功率解耦路径,有效降低了母线电压对电容的依赖,为薄膜电容替换电解电容提供了可能。同时,通过拓扑推演,获得拥有较小电流应力的电路连接方式。最后,搭建100 W的实验样机,证明了所提逆变器的正确性和可行性。

Single stage micro inverter is widely used in photovoltaic power generation because of its simple structure and low cost. However, the existence of double power frequency pulse force will cause the voltage and current of photovoltaic side to fluctuate greatly, which makes the design of maximum power point tracking(MPPT) controller difficult. However, the existing passive decoupling scheme using electrolytic capacitor leads to the shortening of inverter service life. In this paper, a flyback current source micro inverter with power decoupling capability is proposed.By creating a power decoupling path, the topology can effectively reduce the dependence of bus voltage on capacitor, which makes it possible for thin film capacitor to replace electrolytic capacitor. At the same time, the circuit connection mode with smaller current stress is obtained by topology deduction. Finally, a 100 W prototype is built to verify the correctness and feasibility of the proposed inverter.