LCL-LC based active damping parameter design method for grid-connected system

Abstract

The invention discloses a capacitor voltage feedback LCL-LC based controller parameter and active damping parameter design method for a grid-connected system. The design method is on the basis of taking control delay into consideration, and ensures stable phase margin (PM), gain margin (GM) and error of amplitude (EA) of the system, configures a reasonable parameter selection domain, and chooses reasonable controller parameters and active damping coefficients from the parameter selection domain. By adoption of the method, the LCL-LC filter resonance can be effectively restrained, and the stability and the dynamic response performance of the photovoltaic grid-connected system are both effectively improved.

Description

technical field [0001] The invention belongs to the technical field of new energy distributed power generation control in power systems, and considers an LCL-LC grid-connected system controller and active damping parameter design considering system control delay, grid impedance adaptability and grid disturbance The method makes the entire photovoltaic grid-connected system have strong stability and robustness. Background technique [0002] The increasing global energy consumption has greatly increased the demand for renewable energy such as wind power and solar energy. Photovoltaic grid-connected inverters are connected equipment between photovoltaic panels and power grids, and their stability analysis and dynamic response to distributed generation systems have attracted more and more attention. However, photovoltaic grid-connected systems usually use DC-DC and DC-AC two-stage inverters, resulting in a large number of harmonic components in the output voltage, so that the c...

AI Technical Summary

Problems solved by technology

[0004] The grid-connected inverter system based on LCL-LC filter is difficult to design due to too many parameters and the complex relationship between parameters

The Chinese patent application publication number CN103825438A proposes a parameter design method for the main circuit of the LCL-LC filter, but does not mention the system control parameters and the design method of the active damping of the filter

In addition, an article entitled "Step-by-Step controller design for LCL-type grid-connected inverter with capacitor-current-feedback active-damping" published by ChenLeiBao et al. in IEEE Transactions on Power Electronics proposed a step-by-step controller design method using capacitor current feedback. Although the filter system parameter design method is simple and easy to understand, it does not consider the influence of control delay on the system; FeiLi et al. proposed decoupling LCL-LC filter, the parameter design of LCL-LC filter is decomposed into traditional LCL filter parameter design and LC branch parameter design, but this method still only involves the main circuit of LCL-LC filter parameter design without addressing the problem of control parameter design

Images