基于虚拟阻抗的三相逆变器并联系统研究

摘要

在三相逆变器并联系统中，一般采用PQ下垂控制。传统的PQ下垂控制是基于理想模型，每个逆变模块的参数完全一致。然而在实际的逆变器并联系统中，各个逆变模块的电路参数往往无法完全一致，致使模块之间出现环流。为解决该问题，将虚拟阻抗的概念应用于三相逆变器并联系统控制。研究表明，采用虚拟阻抗可以有效解决逆变器并联系统中各个模块之间因为组件和电路参数差异而产生的影响，减小系统环流和改善系统均流。通过仿真和实验对所提方法进行了验证。%PQ droop control is generally used in the parallel system of three-phase inverter. The conventional PQ droop control is based on the ideal model, and the parameters of each inverter module are exactly the same. But in the normal system, the circuit parameters of the inverter modules are often not completely the same, and the circulating current between modules appears. In order to solve the problem, the concept of virtual impedance is applied to the control of three-phase inverter parallel system in this paper. The research shows that the virtual impedance can effectively solve the influence caused by the difference between components and circuit parameters of each module, and reduce the circulating current to improve the performance of current sharing. The simulation and experiments verify the method.