一种可实现双向故障闭锁的双极Y型模块化多电平直流变换器  

Bipolar Y-typed Modular Multilevel DC/DC Converter With Bidirectional Fault Locking

作　　者：马文忠[1] 王晓康[1] 王玉生[2] 郭江浩 焦丽鑫 金琼婷 张景顺 MA Wenzhong;WANG Xiaokang;WANG Yusheng;GUO Jianghao;JIAO Lixin;JIN Qiongting;ZHANG Jingshun(College of New Energy,China University of Petroleum(East China),Qingdao 266580,Shandong Province,China;PetroChina Planning and Engineering Institute,Haidian District,Beijing 100083,China;Rizhao Sunshine Heyuan Power Engineering Co.,Ltd.,Rizhao 276800,Shandong Province,China)

机构地区：[1]中国石油大学(华东)新能源学院,山东省青岛市266580 [2]中国石油天然气股份有限公司规划总院,北京市海淀区100083 [3]日照阳光合源电力工程有限公司设计分公司,山东省日照市276800

出　　处：《电网技术》2024年第5期2122-2132,I0095,I0096-I0100,共17页Power System Technology

摘　　要：直流电网互联通常采用隔离型高压大功率直流变换器,但其存在体积大、成本高及传输效率较低等问题。该文提出一种双极Y型模块化多电平DC/DC变换器,其避免使用中间变压器,实现直流功率双向传输,并且可以有效闭锁双向直流故障。首先分析了变换器拓扑结构及故障闭锁工作原理,并根据桥臂内电势等效原理建立了数学模型。基于变换器臂间、相间能量平衡约束,在闭环控制的基础上引入桥臂电流补偿控制,提升变换器暂态性能。最后,在Matlab/Simulink搭建了采用模块化多电平DC/DC变换器(modularmultilevelDC/DCconverter,DC-MMC)的直流输电系统仿真模型,通过对端口电流、桥臂电流及桥臂电容电压等动态指标的分析,验证了所提DC-MMC双向功率传输控制及双向故障闭锁能力的可行性和有效性。The isolated high-voltage high-power converters,commonly used in the interconnection of HVDC power networks,have the disadvantanges of large volume,high cost and low transmission efficiency.This paper presents a bipolar Y-typed modular multilevel DC/DC converter which achieves the bidirectional transmission of DC power and effectively locks the bidirectional DC faults without using the intermediate transformers.Firstly,the topology of the converter and the working principle of the fault blocking are analyzed,and a mathematical model is established according to the principle of potential equivalence in the bridge arm.Based on the energy balance constraints of the inter-arm and inter-phases,the bridge arm current compensation control is then introduced under the closed-loop control to improve the transient performance of the transformer.Finally,a DC-MMC simulation model is built in the Matlab/Simulink.The feasibility and validity of the proposed DC-MMC bidirectional power transmission control and the bidirectional fault blocking capability are verified by analyzing the dynamic parameters such as the port current,the arm current and the arm capacitance voltage.

关 键 词：模块化多电平DC/DC变换器 直流电网 桥臂能量平衡 双向直流功率传输 双向直流故障闭锁 

分 类 号：TM721[电气工程—电力系统及自动化]