基于非对称LCL滤波器的并网逆变器原理及控制研究

Power converters with Low total inductance and cost of stock preparation and installation will do help for the application of distributed power generator system. Compared with the conventional LCL-filter, recently, the total inductance of higher-order power filter can be reduced, but at cost of the more complicated structure, as well as the more expenses of stock preparation and installation. In order to combine the simple structure merit of LCL-filter with the less total inductance characteristic of other higher order power filter, a new asymmetric LCL-filter is proposed. Firstly, the principle of the proposed filter and the control of grid-tied converter are investigated. Secondly, the impedance stability based analysis on the grid-tied converter using asymmetric LCL-filter is carried out. Thirdly, the power coupling and interactions between multiple grid-tied power converters are studied, especially under the symmetric grid condition. Finally,the verification is developed through simulation and experiments. The proposed asymmetric LCL-filter shall benefit the technique development of three-phase grid-tied inverter in a high efficiency and low cost way. And the research foundation on stability analysis of power converters-based micro-grids can also be strengthened, inducing new issues and new methodologies.

低电感、低备料与安装成本的并网逆变器及控制技术有助于分布式发电系统的推广应用。相对于传统LCL滤波器，近年来出现的各种高阶滤波器能进一步降低总电感量；然而，因结构复杂度增加，备料以及安装成本亦有所增加。.为综合传统LCL滤波器结构简单以及其他高阶滤波器总电感量少的各自优点，本项目提出了一种新型三相非对称LCL滤波器方案。首先，研究非对称滤波器的基本原理及控制规律；其次，研究非对称条件下并网逆变器系统稳定理论及判据；再次，研究非对称条件下并联多并网逆变器之间交互影响及解耦方法；最后进行仿真和实验验证。.新型非对称LCL滤波器的提出，能有效促进三相高效低成本并网逆变器技术的进一步发展，亦能为基于电力电子变换器微电网的非对称工况稳定控制研究提供新的思路与方法。

低电感、低备料与安装成本的并网逆变器及控制技术有助于分布式发电系统的推广应用。相对于传统LCL滤波器，近年来出现的各种高阶滤波器能进一步降低总电感量；然而，因结构复杂度增加，备料以及安装成本亦有所增加。. 为综合传统LCL滤波器结构简单以及其他高阶滤波器总电感量少的各自优点，本项目提出了一种新型三相非对称LCL滤波器方案。首先，研究非对称滤波器的基本原理及控制规律；其次，研究非对称条件下并网逆变器系统稳定理论及判据；再次，研究非对称条件下并联多并网逆变器之间交互影响及解耦方法；最后进行仿真和实验验证。. 新型非对称LCL滤波器的提出，能有效促进三相高效低成本并网逆变器技术的进一步发展，亦能为基于电力电子变换器微电网的非对称工况稳定控制研究提供新的思路与方法。