Method for suppressing multiple resonant peaks when grid-connected inverters are operated asynchronously in parallel under weak grid

CN115833178BActive Publication Date: 2026-07-03XIAN UNIV OF TECH

Patent Information

Authority / Receiving Office: CN · China
Patent Type: Patents(China)
Current Assignee / Owner: XIAN UNIV OF TECH
Filing Date: 2022-12-15
Publication Date: 2026-07-03

AI Technical Summary

Technical Problem

In weak power grids, when multiple grid-connected inverters operate asynchronously in parallel, traditional resonance suppression methods cannot effectively suppress multiple resonance peaks simultaneously, leading to a decline in grid current quality and affecting power system safety.

Method used

An improved DD-Σ current control method and an improved virtual admittance method are adopted. By adaptively adjusting the control parameters and connecting the virtual admittance in parallel at the output of each inverter, the variable and fixed resonance peaks are suppressed respectively.

Benefits of technology

It effectively suppresses two resonance peaks when multiple grid-connected inverters are operating asynchronously in parallel, improves grid-connected power quality, and reduces the difficulty of control parameter design.

✦ Generated by Eureka AI based on patent content.

Smart Images

Figure CN115833178B_ABST

Patent Text Reader

Abstract

The application discloses a method for suppressing multiple resonance peaks when a plurality of grid-connected inverters are connected in parallel and run asynchronously under a weak power grid, and is implemented according to the following steps: Step 1: a mathematical model of multiple inverters connected in parallel and running asynchronously in an s domain is established, and variable resonance peaks and fixed resonance peaks are obtained; Step 2: the suppression parameters of the variable resonance peaks are determined, and an improved D-D-Σ current control method is established; Step 3: the inherent parameters of the filter are determined, and an improved virtual admittance method is established; Step 4: the improved D-D-Σ current control method is used to suppress the variable resonance peaks, and the improved virtual admittance method is used to suppress the fixed resonance peaks, and finally the suppression of the two resonance peaks of the grid-connected current is completed. The application avoids the problem that the control parameters are difficult to design due to the use of only one kind of control method, and also avoids the problem that only one kind of control method is difficult to suppress the two resonance peaks at the same time, thereby improving the resonance suppression effect and reducing the design difficulty of the control parameters.

Need to check novelty before this filing date? Find Prior Art