龚凯,肖晃庆,张展,何宏亮,黄莹,李岩
GONG Kai,XIAO Huangqing,ZHANG Zhan,HE Hongliang,HUANG Ying,LI Yan

• 1:华南理工大学电力学院
• 2:浙江大学电气工程学院
• 3:南方电网科学院有限责任公司

摘要(Abstract)：

随着新能源发电装机容量的逐年增加，优化其换流器并网控制策略对于提升系统稳定性具有极为重要的作用。目前新能源并网换流器的控制策略主要有GFL（跟网型）和GFM（构网型）两种，其中GFL在弱电网下稳定性较差，GFM在强电网下易失稳。为此，首先提出一种含自适应系数的并网换流器混合同步控制结构，将GFL常用的锁相环与GFM常用的功率同步环结合，利用一个比例系数形成混合型同步控制环。随后建立了相应的小信号模型，在此基础上根据小信号稳定性分析结果提出了自适应参数取值方法。最后仿真验证了采用自适应混合同步控制的换流器并网系统在短路比为1的弱电网和短路比为30的强电网下都能保持良好的稳定性，为新能源并网换流器的稳定运行提供了一种新的、适用于不同电网条件的控制方案。
As the capacity of renewable power plants connected to the grid increases year by year, optimizing the control strategies for their converters becomes crucial for enhancing system stability. Currently, the primary control strategies in renewable power plants focus on grid-following(GFL) and grid-forming(GFM) converters. The former tends to exhibit poor stability in weak grids, while the latter may lose stability in strong grids. To address this challenge, the paper first proposes a hybrid synchronous control structure for grid-connected converters that incorporates adaptive coefficients. This structure combines the phase-locked loop(PLL) commonly used by GFL converters with the power-synchronization loop(PSL) utilized by GFM converters, creating a hybrid synchronous control loop through a proportional coefficient. Subsequently, the corresponding small-signal model is developed, and based on the analysis results of small-signal stability, a method for determining adaptive parameter values is introduced. Finally, simulation results validate that the converter-connected system employing adaptive hybrid synchronous control maintains good stability in weak grids with a short-circuit ratio of 1 and in strong grids with a short-circuit ratio of 30. This provides a new control scheme suitable for the stable operation of grid-connected converters in renewable power plants under varying grid conditions.

关键词(KeyWords)： 跟网型控制;构网型控制;混合同步控制环;小信号稳定性;特征值分析
grid-following control;grid-forming control;hybrid synchronous control loop;small signal stability;eigenvalue analysis

Abstract:

Keywords:

基金项目(Foundation): 中国南方电网有限责任公司创新项目（ZBKJXM20232278）

作者(Author): 龚凯,肖晃庆,张展,何宏亮,黄莹,李岩
GONG Kai,XIAO Huangqing,ZHANG Zhan,HE Hongliang,HUANG Ying,LI Yan

DOI: 10.19585/j.zjdl.202411002

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