摘要
在弱电网条件下,由于电网阻抗存在宽范围变化的特点,将会对并网逆变器的运行稳定性带来挑战。针对这个问题,建立三相LCL型并网逆变器电流双闭环控制的并网系统,采用基于阻抗模型的频域分析方法,通过分析并网逆变器等效输出阻抗的特点和电网阻抗对系统稳定性的影响,对并网逆变器系统输出等效阻抗进行重塑。在重塑方法上,提出一种具有宽频特性的阻抗重塑环节,通过该阻抗重塑环节可以在宽频范围内提高系统等效输出阻抗的相位,从而提高系统对弱电网的适应性。最后,通过Matlab/Simulink仿真,证明了理论分析的合理性以及所提出阻抗重塑方法的有效性。
Under weak grid conditions,due to the characteristics of wide-range changes in grid impedance,it will pose challenges to the operational stability of grid-connected inverters.In response to this problem,agrid-connected system with double closedloop current control of the three-phase LCL grid-connected inverter is established.The frequency domain analysis method based on the impedance model is adopted to analyze the characteristics of the equivalent output impedance of the grid-connected inverter and the pair of grid impedance.The influence of system stability reshapes the output equivalent impedance of the gridconnected inverter system.In the reshaping method,an impedance reshaping link with broadband characteristics is proposed,through which the phase of the equivalent output impedance of the system can be improved in a wide frequency range,thereby improving the adaptability of the system to weak power grids.Finally,Matlab/Simulink simulation proves the rationality of the theoretical analysis and the effectiveness of the proposed impedance remodeling method.
作者
郑国超
严柏平
王富立
黄大卓
沈春城
ZHENG Guochao;YAN Baiping;WANG Fuli;HUANG Dazhuo;SHEN Chuncheng(Guangdong University of Technology School of Automation,Guangzhou 51006,China;Guangdong Power Grid Co.,Ltd.Chaozhou Power Supply Bureau,Chaozhou 521000,China)
出处
《河北电力技术》
2022年第2期24-29,共6页
Hebei Electric Power
基金
广东省自然科学基金(2018A030313010),广州市科技计划项目(202102021135)。
关键词
弱电网
LCL型并网逆变器
阻抗重塑
稳定裕度
相位补偿
weak grid
LCL grid-connected inverter
impedance reshaping
stability margin
phase compensation
