基于单相Z源光伏并网逆变器的调制策略研究

Research on Modulation Strategy of Single-phase Z-source Photovoltaic Grid-connected Inverter

传统单相Z源逆变器允许同一桥臂开关管直通,提高了系统可靠性。利用Z源逆变器的这种优势,提出改进型脉宽调制(PWM)策略,并分析换流过程和各功率器件的开关应力,结合通态损耗、开关损耗和电感损耗模型定量计算逆变器效率。与简单升压控制策略相比,改进型PWM策略提高了单相Z源逆变器效率。实验结果证明了所提PWM策略的可行性和正确性。

The through state is allowed in traditional single-phase Z-source inverter, and the reliability of the system is improved.With the advantages of Z-source inverter, modified PWM strategy is put forward.Switch commutation process and the stress of power devices are analyzed, and the efficiency of the inverter with conduction losses model, switching losses model and inductance losses model are calculated.Compared with the simple Boost control strategy,the efficiency of sin- gle-phase Z-source inverter is improved in the modified PWM strategy.Experimental results show the proposed PWM strat- egy is feasible and correct.