摘要
±800 kV特高压混合多端柔性直流输电工程的柔直换流站采用柔直阀组串联的形式,每个柔直阀组均由一定比例的基于MMC结构的半桥功率模块和全桥功率模块组成。MMC换流阀结构中包含电容器组,投入工作前必须先完成换流阀充电才能正常工作。在柔直换流站进行运行方式转换时,可能出现第二阀组投入的情况,此时第二阀组直流端口处于短路状态,不能使用传统的充电策略。文章分析了第二阀组投入时的充电问题,提出了一种用于柔直换流站第二阀组的充电策略,并在厂内±10 kV半桥/全桥混合型MMC样机上开展实验验证,结果显示该充电策略可以解决半桥/全桥混合型MMC换流阀串联的第二阀组投入时充电失败问题。
The flexible DC valve group in series is adopted for the flexible DC converter station of±800 kV ultra high voltage multi-terminal flexible direct current transmission project(VSC-UHVDC).Each flexible DC valve group consists of a certain proportion of half-bridge power module and full-bridge power module based on MMC structure.The structure of MMC converter valve contains capacitor bank which,before putting into operation,can not operate normally until the charging of the converter valve is completed.In case of operation mode transformation of the flexi-ble DC converter station,such situation as operation of the second valve group may occur.At this time,the DC port of the second valve group is in the short circuit state and the traditional charging strategy cannot be used.In this paper,the charging issue in the operation of the second valve group is analyzed and a kind of charging strategy of the second valve group for the flexible DC converter station is proposed and the experimental verification on the±10 kV/60 MW half-bridge&full-bridge hybrid modular multi-level converter valve prototype is performed.The result shows that the charging strategy can effectively solve the problem of charging failure in case of switching of the series second valve group of half-bridge and full-bridge hybrid MMC converter.
作者
涂小刚
宋志顺
常立国
洪俊
TU Xiaogang;SONG Zhishun;CHANG Liguo;HONG Jun(Xi'an XD Power System Co.,Ltd.,Xi'an 710065,China;Xi'an Gentle Mellow Technology Co.,Ltd.,Xi'an 710077,China)
出处
《高压电器》
CAS
CSCD
北大核心
2021年第11期101-107,共7页
High Voltage Apparatus
基金
广东省重点领域研发计划资助(2019B111109001)。
