多逆变器并网系统谐振混合阻尼参数设计

Hybrid Damping Parameters Design of Resonance for Multi-inverter Grid-connected System

多逆变器并网系统谐振是高比例新能源新型电网必须解决的问题。文中分析了改进型有源阻尼、阻抗重塑和有源阻尼器的优缺点后,认为混合阻尼策略更符合工程经济需求。首先,介绍了单台LCL型逆变器混合阻尼参数设计过程;然后,在分析多逆变器系统谐振机理的基础上,根据混合阻尼的阻尼系数特点,提出先确定有源阻尼参数再确定无源阻尼参数,并采用总谐波率和谐波系数两个指标评价并网电能质量的参数设计方法;最后,在Matlab/Simulink仿真平台上进行验证。结果表明,所提方法设计的混合阻尼参数对系统谐振具有良好的抑制效果,并且能较好地适应系统阻抗的变化。

Resonance of multi-inverter grid-connected system is a problem that must be solved in new power grid with high proportion of renewable energy. After analyzing the advantages and disadvantages of the improved active damping, impedance remodeling and active damper, it is considered that the hybrid damping strategy is more in line with the economic needs of the project. Firstly, the design process of hybrid damping parameters of single LCL inverter is introduced. Based on the analysis of resonance mechanism of multi-inverter system, according to the characteristics of hybrid damping coefficient, a parameter design method is proposed to determine the active damping parameters firstly and then the passive damping parameters, and the total harmonic rate and harmonic factor are used to evaluate the grid-connected power quality. Finally, it is verified on the Matlab/Simulink simulation platform. The results show that the hybrid damping parameters designed by the proposed method have a good suppression effect on the system resonance and can adapt well to the change of system impedance.