带消弧选线功能的并网逆变器研究

Research on Grid-connected Inverter With Arc Suppression and Fault Line Selection Function

为提高分布式逆变电源在不接地系统中的作用,在此提出了一种带消弧选线功能的并网逆变器。该逆变器不仅能向系统输送能量,还能在系统发生金属性单相接地故障时向系统提供工频感性电流和高频选线信号,从而达到消弧和选线的作用。在此首先提出了一种带消弧选线功能的三相四线制逆变器拓扑结构,并对该结构进行等效建模。通过分析系统金属性单相接地时各电气量的特征,提出了一种基于金属性单相接地的功率前馈无差拍控制方法。最后通过仿真与实验验证了所提结构与方法的正确性。

In order to make distributed inverters play a more important role in the ungrounded system,a grid-connected inverter is presented which can be achieved quickly and accurately arc suppression and find fault lines.The inverter can not only transmit energy to the power grid,but also provide power frequency inductive current and high frequency line selection signal to the power grid when the metal single-phase grounding fault occurs,so as to eliminate the arc and the grounding fault line selection.Firstly,a three-phase four-wire photovoltaic inverter with arc suppression function and the fault line selection function is proposed,and the equivalent model of the structure is established.Based on the analysis of the variation of electrical quantity in the system with metal single-phase grounding,a power feed-forward deadbeat control method based on metal single-phase grounding is proposed.Finally,the correctness of the proposed structure and method is verified by the simulation and experiment.