一种改进的正反激并网微型逆变器

反激逆变器存在输出电流纹波大、功率容量小等缺点;交错并联反激逆变器存在开关器件多、控制方式复杂等缺点。针对上述问题,提出一种双变压器有源钳位正反激光伏并网逆变器结构,该逆变器二次侧仅用两个开关管,控制方式简单、可靠性高;采用双变压器可以分担功率、减小单个磁性元件尺寸。对该逆变器的电路拓扑、电流控制策略、稳态原理、特性等进行深入分析。最后通过仿真和实验验证了该逆变器结构的可行性。

An Improved Forward-Flyback Grid-Connected Micro-Inverter

The flyback grid-connected micro-inverter has larger current ripple and lower output power, while the interleaved flyback grid-connected micro-inverter needs many switching devices and complex control strategy. Therefore, a novel single-stage forward-flyback grid-connected micro-inverter with two transformers is proposed in this paper. The proposed inverter uses only two switches in the secondary side to simplify the control strategy and guarantee high reliability. The utilization of two transformers in the topology can split the power and reduce the size of single transformer. Detailed analyses on the topology of the proposed inverter, the current control strategy, steady principle and characteristics of the circuit are presented. In addition, the simulation results and experimental data verify the feasibility of the micro-inverter.