双频单相并网逆变器的拓扑及控制方法研究

Research on Topology and Control Method of Dual Frequency Single Phase Grid Connected Inverter

为了进一步降低单相并网逆变器的成本,提高并网电流的质量和并网逆变器的效率,提出了一种并联型双频单相并网逆变器。并联型双频单相并网逆变器的主电路包含低频功率单元和高频消谐波单元,并网电流为低频功率单元电流和高频消谐单元电流之和,使得并网电流中的谐波得到了有效抑制。在介绍了并联型双频单相并网逆变器的拓扑结构和工作原理的基础上,给出了并网逆变器的控制策略,整个控制系统包括2个相互耦合的电流环,实现了对并网电流的控制。实验结果验证了理论分析的正确性。

In order to reduce the cost of single-phase grid connected inverter and improve the efficiency of grid connected inverter,a parallel dual frequency single phase grid connected inverter was proposed. The low frequency power unit and high frequency harmonic elimination unit were included in the main circuit of parallel dual frequency single phase grid connected inverter. The grid connected current was the sum of the low frequency power unit current and the high frequency harmonic elimination current which effectively suppressed the harmonics in the grid connected current. The control strategy of the parallel single- phase grid connected inverter was given based on introducing the topology structure and working principle of dual frequency single- phase grid connected inverter. The control system contained two mutually coupled current loops,which realized the control of the grid current. The experimental results verify the correctness of the theoretical analysis.