LCL filter parameter design method and device based on damping ratio and medium

Abstract

The invention provides an LCL filter parameter design method and device based on a damping ratio and a medium, and the method comprises the steps: firstly selecting converter side inductance and filter capacitance parameters according to a conventional LCL filter design method; then, using the damping ratio for optimally designing the values of the damping resistor and the output side inductor. Inaddition, the invention further provides an iterative optimization scheme for the total inductance value and the resonant frequency. The optimal damping ratio 0.28 is preferably adopted, and the damping ratio can guarantee stable operation of the converter system with the LCL filter with the minimum damping loss. The method is few in design iteration, can guarantee that the high-frequency attenuation design of the LCL filter is accurate, avoids the stability risk caused by the unreasonable damping design, guarantees that the selection of the current control parameters is simple and direct, and is suitable for an occasion that the high-frequency component of the output side voltage of the LCL filter is lower.

Description

technical field [0001] The invention relates to the field of converter filter design, in particular to a damping ratio-based LCL filter parameter design method. Background technique [0002] Compared with traditional inductive filters, LCL filters have better attenuation performance for high-frequency current harmonics. In recent years, in order to meet the increasingly stringent grid-connected rules, more and more grid-connected converters have begun to use LCL filters to filter out switching subharmonics in the grid-connected current. However, there is an inherent resonant peak on the amplitude-frequency characteristic curve of the LCL filter, which easily leads to the instability of the converter system and brings challenges to the design of the current controller. In order to ensure the stability of the control, the converter system with the LCL filter generally adopts the method of active damping or passive damping to suppress the resonance peak. [0003] The main adv...

AI Technical Summary

Problems solved by technology

[0007] 1) The design of passive damping value is inaccurate, which may lead to converter instability or excessive damping loss due to unreasonable damping value;

[0008] 2) Passive damping and high-frequency current attenuation require multiple iterative adjustments, resulting in low design efficiency and poor design accuracy

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