低开关频率下并网变换器的控制及稳定性分析

黄鹭鹭; 高波

doi:10.19912/j.0254-0096.tynxb.2021-1055

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太阳能学报 ›› 2023, Vol. 44 ›› Issue (4) : 332-340. DOI: 10.19912/j.0254-0096.tynxb.2021-1055

低开关频率下并网变换器的控制及稳定性分析

黄鹭鹭, 高波

作者信息 +

CONTROLAND STABILITY ANALYSIS OF GRID-CONNECTED INVERTER UNDER LOW SWITCHING FREQUENCY

Huang Lulu, Gao Bo

Author information +

文章历史 +

摘要

分析LCL型并网变换器网侧电流反馈控制和变换器侧电流反馈控制阻尼系统的稳定性。从主导极点的角度分析低开关频率下2个共轭复根的位置决定了根轨迹的走向,进而影响系统的稳定。已有的有源阻尼方法都是各自独立提出的,缺乏系统的研究以便于提出新的有源阻尼控制方法,通过对并网变换器稳定控制的分析可得到阻尼控制方法的本质。数字延时本质上是一种串联校正,揭示了延时改变系统相位特性。数字延时的相位滞后在某些情况下有利于系统稳定,但这取决于测量反馈量的传感器位置和谐振频率。该文在离散域下对电流控制器参数进行设计,从工程实用的角度给出快速确定控制器参数的方法。最后通过仿真和试验验证理论分析的正确性。

Abstract

The stability of damping resonance of grid-side current feedback control and inverter-side current feedback control of LCL grid-connected inverter is analyzed. From the standpoint of the dominant poles, the positions of the two conjugate complex roots at low switching frequency determine the direction of the root locus, which in turn affects the stability of the system. The existing active damping methods are proposed independently, and there is a lack of systematic synthesis in order to propose novel active damping control methods. The essence of the damping resonance can be obtained by analyzing the stability control of grid-connected inverters. Digital time-delay is essentially a series correction, revealing that the delay changes the system phase characteristics. The phase lag of the digital delay is beneficial to system stability in some cases, but it depends on resonance frequency and the position of current sensor which is utilized for feedback variable. The paper designs the current controller parameters in the discrete domain, and gives a method to determine controller parameters quickly and exactly from the point of view of engineering practicality. The theoretical analysis is validated by simulation and experimental results.

导出引用

黄鹭鹭, 高波. 低开关频率下并网变换器的控制及稳定性分析[J]. 太阳能学报. 2023, 44(4): 332-340 https://doi.org/10.19912/j.0254-0096.tynxb.2021-1055

Huang Lulu, Gao Bo. CONTROLAND STABILITY ANALYSIS OF GRID-CONNECTED INVERTER UNDER LOW SWITCHING FREQUENCY[J]. Acta Energiae Solaris Sinica. 2023, 44(4): 332-340 https://doi.org/10.19912/j.0254-0096.tynxb.2021-1055

中图分类号： TK513.5

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