电感磁芯软饱和特性约束下三相LCL型并网变换器单环控制稳定性分析与设计  

Stability Analysis and Design of LCL-type Grid-connected Converters With Single-loop Control Under the Constraint of Soft Saturation Characteristics of Inductor Magnetic Core

作　　者：李小强[1] 蒋苏 聂文娟 李昌易 伍小杰[1] 齐东迁 LI Xiaoqiang;JIANG Su;NIE Wenjuan;LI Changyi;WU Xiaojie;QI Dongqian(China University of Mining and Technology,Xuzhou 221116,Jiangsu Province,China;Dianguang Explosion Protection Technology Co.,Ltd.,Yueqing 325600,Zhejiang Province,China)

机构地区：[1]中国矿业大学,江苏省徐州市221116 [2]电光防爆科技股份有限公司,浙江省乐清市325600

出　　处：《中国电机工程学报》2021年第24期8585-8599,共15页Proceedings of the CSEE

基　　金：国家自然科学基金(青年科学基金项目)(51807196);中国博士后科学基金项目(2019M661983)。

摘　　要：磁粉芯材质电感具有软饱和非线性特性,其感值随电流变化而改变。在三相LCL型并网系统中,三相交流滤波电感呈现时变不对称特性,导致控制系统模型之间存在交叉耦合,传统单电流环控制的稳定性设计可能失效。为此,该文考虑磁粉芯电感的软饱和特性,研究三相滤波电感的时变交错非线性特性,并采用广义奈奎斯特稳定判据,分析三相LCL型并网变换器在两相静止坐标系下的谐振分布特性,提出单电流环控制下的稳定设计约束。最后,仿真和实验结果验证理论分析与设计的正确性和有效性。Inductors based on magnetic powder core material have soft saturation nonlinear characteristics, whose inductances vary with the current. In three-phase LCL-type grid-connected systems, three-phase AC filter inductances present the time-varying asymmetric characteristics, which would lead to the cross-coupling in the control system models,and thus the stability design of the traditional single-current-loop control may fail. Therefore, considering the soft saturation characteristics of magnetic powder core-based inductors, this paper investigated the time-varying interlaced nonlinear characteristics of three-phase filter inductances.Then, the generalized Nyquist stability criterion was used to analyze the resonance distribution characteristics of three-phase LCL-type grid-connected converters in the two-phase stationary coordinate reference frame, and the stability design constraints with single-current-loop control were proposed. Finally,simulation and experimental results verified the effectiveness of theoretical analysis and stability design.

关 键 词：磁芯软饱和 LCL滤波器 三相并网变换器 单电流环控制 稳定性 多输入多输出系统 

分 类 号：TM464[电气工程—电器]