DCM变频控制的反激单相光伏并网微型逆变器  

Flyback single-phase photovoltaic grid-connected micro-inverter with DCM variable-frequency control

作　　者：李佳龙 杨燕翔 王军 阎铁生 呼爱国 Li Jialong;Yang Yanxiang;Wang Jun;Yan Tiesheng;Hu Aiguo(School of Electrical Engineering and Electronic Information,Xihua University,Chengdu,610039,China;Dept.of Electr.&Comput.Eng.,Univ.of Auckland,Auckland 1142,New Zealand)

机构地区：[1]西华大学电气与电子信息学院,成都610039 [2]奥克兰大学电气与计算机工程系,新西兰奥克兰1142

出　　处：《电测与仪表》2020年第2期129-134,共6页Electrical Measurement & Instrumentation

基　　金：国家重点研发计划资助项目(2018YFB0905200);西华大学研究生创新基金项目资助(ycjj2018086;ycjj2018049)

摘　　要：工作在电感电流断续模式下的反激单相光伏(Photovoltaic,PV)并网微型逆变器,由于开关频率恒定,所以在正弦波过零点附近或瞬时输出功率较低时,存在较大的开关损耗问题。为此,提出了一种新的变频控制策略。使得开关频率跟随瞬时输出功率变化而变化,在低瞬时输出功率时,自主降低开关频率,从而能有效减小开关损耗。利用恒定原边电流峰值单元和开关频率控制单元来实现所提出的变频控制策略,最后通过PSIM仿真验证了采用DCM变频控制的反激单相光伏并网微型逆变器的性能;仿真结果表明所提控制策略能有效降低正弦波过零点附近瞬时输出功率较低时的开关频率,从而降低逆变器的开关损耗,提高整体效率,同时还能保证输出的并网电流有较小的THD。Due to the constant switching frequency,the switching loss of the flyback single-phase photovoltaic grid-connected micro-inverter working at discontinuous conduction mode is large when the sinusoidal wave is near zero or the instantaneous output power is low. Therefore,a novel DCM variable frequency control strategy is proposed in this paper.With this control strategy,the switching frequency varies with the instantaneous output power,and the switching frequency can be reduced independently at the low instantaneous output power,which can effectively reduce the switching loss. The proposed control strategy is implemented by constant primary current peak unit and switching frequency control unit. Finally,the feasibility of the flyback single-phase photovoltaic grid-connected inverter with DCM variable frequency control is verified by PSIM simulation software. The simulation results show that the proposed control strategy can effectively reduce the switching frequency when the sinusoidal wave is near zero or the instantaneous output power is low,thus reducing the switching loss and improving the overall efficiency of the inverter. It also ensures that the output current has a smaller THD.

关 键 词：反激 光伏 微型逆变器 电感电流断续模式 变频控制 

分 类 号：TM46[电气工程—电器]