摘要
直流电网是解决新能源接入,实现远距离大容量功率传输的有效技术手段。直流变压技术是实现直流电网不同电压等级变换的核心。该文提出一种新型模块化多电平DC/DC变压器拓扑,借助一二次侧直流系统共享电容及模块化动态投切原理实现直流电压等级变换。同时针对不同应用场景,对变压器拓扑结构以及控制方式进行适应性调整。较之隔离型模块化多电平直流变压器,所提出的新型变压器结构简单,经济性和灵活性更优,控制系统高效简单,同时依托变比灵活调控,可主动参与潮流控制。利用PSCAD/EMTDC搭建仿真模型,并验证新型直流变压器的可行性与先进性。
The construction of DC power grid is an effective solution to integrate renewable energy and realize long distance and large capacity power transmission. DC/DC transformer is the key component to achieve different voltage level conversion. This paper proposed a new modular multilevel DC/DC transformer topology,which is based on sharing capacitors by both sides and modular dynamic switching principle. Besides different transformer topologies and control methods have been designed aiming at some specific application scenarios. Compared with isolated DC/DC structure based on modular multilevel converter, this novel transformer is simple in structure that reduces the number of devices significantly, and has the advantage of better economy, improved flexibility and simplified control loop. As the new transformer is able to regulate the transformer ratio flexibly, it can actively participate in DC power flow control. The feasibility and advance of the proposed DC transformer have been verified on the PSCAD/EMTDC simulation platform.
作者
李斌
张伟鑫
LI Bin, ZHANG Weixin(Key Laboratory of Smart Grid of Ministry of Education （Tianjin University）, Nankai District, Tianjin 300072, China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2018年第5期1319-1328,共10页
Proceedings of the CSEE
基金
国家自然科学基金项目(51677126)~~
关键词
直流电网
直流变压器
模块化多电平
潮流控制
非隔离型变压器
DC grid
DC transformer
modular multilevel converter
power flow control
non-isolated transformer
