三相光伏并网逆变器电压环设计与实现

摘要

三相光伏并网逆变器的直流母线起到平衡直流输入功率与交流输出功率的作用.首先对三相并网逆变器母线电压环进行建模,在此基础上分析了电网电压不平衡对母线电压和并网电流的影响.通过在母线电压环路中引入自适应格型陷波器(ANF),解决了母线电压环动态性能和稳态总谐波畸变率(THD)性能之间的矛盾.最后通过实验验证了控制策略的有效性.%The DC-bus balances the input direct current power and the output alternating current power in the three-phase photovoltaic grid-connected inverter.The impact which the unbalanced grid voltage has on the direct current-bus voltage and the grid current,is analyzed firstly based on the model of the direct current-bus voltage loop.The contradiction between the dynamic response of the direct current-bus voltage loop and the grid current's steady state total harmonic distortion(THD) performance is solved by the adaptive notch filter(ANF).Finally,the effectiveness of the proposed control strategy is verified by the experiment results.