新型三相非隔离光伏逆变器拓扑研究

Research on New Topology of Three-phase Transformerless PV Inverters

以非隔离型三相光伏逆变器为研究对象,借鉴非隔离型单相拓扑特点和形成规律,推演出适用于共模漏电流抑制的新型三相拓扑,并以新型三相零电压整流器(zero voltage rectifier,ZVR)拓扑为例进,分析了电路工作原理,然后探讨了调制对系统共模电压的影响,并提出基于布尔逻辑运算的调制方法,保证共模电压恒定,有效抑制了系统共模漏电流,最后在TMS320F28335 DSP+XC3S400 FPGA数字控制硬件实验平台上对提出方案进行实验研究,结果验证了该文提出方案的可行性和有效性。

Three-phase transformerless photovoltaic （PV） inverters were investigated. With the generation mechanism of single-phase topology, the new three-phase transformerless PV inverter topologies were derived. Take the new three-phase zero voltage rectifier （ZVR） topology for example, its operation principle was analyzed. The effect of the modulation strategy on the common mode voltage （CMV） was discussed. A new modulation solution based on the Boolean logic fi^nction was proposed to achieve the constant common mode voltage, so as to eliminate the leakage current. Finally, the experimental tests were carried out on the digital control platform with TMS320F28335 DSP and XC3S400 FPGA. The results verify the effectiveness of the proposal.