光伏级联并网系统模块单元共模干扰建模及分析  

Modeling and Analysis of Common Mode Interference of Cascaded Photovoltaic Grid-connected System Module

作　　者：孟辉 朱自立 陈恒林[1] MENG Hui;ZHU Zili;CHEN Henglin(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,Zhejiang Province,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《中国电机工程学报》2023年第12期4717-4725,共9页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2018YFB1500700)。

摘　　要：为提高电能转换效率、降低器件的电压应力,大型光伏发电系统通常采用级联式拓扑、模块化设计。建立光伏级联系统模块单元的共模干扰模型是研究模块化光伏级联系统的电磁兼容特性,实施电磁兼容量化设计的基础。该文首先提出一种多绕组变压器结构电容的测试方法及等效共模耦合电容的计算方法,建立多绕组变压器高频共模耦合模型,对高频多绕组变压器各绕组之间的共模干扰耦合关系进行分析和评估;之后通过研究模块单元的共模干扰产生及耦合机理,建立一种新型LLC谐振变换器共模等效电路模型,并建立模块单元及系统的共模模型;最后,为解决大功率系统传导干扰测试困难的问题,采用退耦电容和高频磁环来隔离外部干扰,对功率缩比样机的共模电流进行测试。实验测试结果验证了所建模型的有效性。To improve the power conversion efficiency and reduce the voltage stress of devices,large-scale photovoltaic power generation systems usually adopt cascaded topology and modular design.Building the common mode(CM)interference model of cascaded photovoltaic system module is the basis for studying the electromagnetic compatibility(EMC)characteristics of the system and implementing the forward design of EMC.First,this paper studies the measurement method of structural capacitance of multi-winding transformer and the calculation method of equivalent CM coupling capacitance to build the high-frequency CM model of multi-winding transformer,thus revealing the CM interference coupling relationship between windings of high-frequency multi-winding transformers.Then,by analyzing the CM interference generation and coupling mechanism in a module,a new CM equivalent circuit model of an LLC resonant converter is built,and the CM model of a module is obtained.Finally,the CM current of the power scaled prototype is measured by using decoupling capacitor and high-frequency magnetic ring to isolate external interference.The measurement results verify the feasibility of the modeling method and the effectiveness of the model.

关 键 词：电磁兼容 模块化 多绕组变压器 LLC谐振变换器 共模干扰模型 

分 类 号：TM46[电气工程—电器]