摘要
柔性直流输电工程通过投入限流电阻来限制启动过程中的过电流,但目前缺乏对限流电阻本体的保护措施,存在保护空白区。因此,首先分析了MMC-HVDC启动过程中限流电阻的电气特性和现有控保策略,阐明了现有保护方法存在空白区的现状。然后根据限流电阻负荷特性提出了反时限保护模型,并设计了反时限保护电路。进而系统性提出了限流电阻保护配置方案,方案以反时限保护作为限流电阻本体的主保护,同时配备了过流Ⅰ段快速保护、过流Ⅱ段快速保护、充电时间保护3种辅助保护方法。最后依托厦门柔性直流输电工程给出了限流电阻保护设计实例并进行了相关试验。在某起试验中,充电电流未正常衰减,限流电阻热效应积累严重,反时限保护在4.67 s后及时动作,验证了所提出的限流电阻保护策略的正确性和有效性。
The over-current in MMC-HVDC startup process is limited by the current suppression resistor, but there is a blank area in protecting current suppression resistor. First,we analyzed the electrical characteristics and the existing control strategy of the current suppression resistor, and described the current situation of the protection blank area in the existing protection methods. Then, we proposed an inverse time protection model according to the load characteristics of current suppression resistor, and designed an inverse time protection circuit. Moreover, we put forward systematically the scheme of current suppression resistor protection configuration The scheme uses inverse time protection as the main protection of current suppression resistor, and three kinds of auxiliary protection methods are equipped with over-current Ⅰsegment fast protection, over-current Ⅱ segment rapid protection and charge time protection. Finally, based on the Xiamen HVDC flexible transmission project, the design example of the current suppression resistor protection was given and the related tests were carried out. In one test, the charging current is not attenuated and the thermal effect of the current suppression resistor is seriously accumulated, and then the inverse time protection is acted in time after 4.67 s. The test results verify the correctness and effectiveness of the current suppression resistor protection strategy proposed in this paper.
作者
李超
李钢
董云龙
胡文旺
唐志军
晁武杰
LI Chao;LI Gang;DONG Yunlong;HU Wenwang;TANG Zhijun;CHAO Wujie(State Grid Fujian Electric Power Research Institute,Fuzhou 350007,China;NR Electric Co.,Ltd.,Nanjing 211102,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2019年第1期39-45,共7页
High Voltage Engineering
基金
国家电网公司科技项目(52130417000K)~~
关键词
柔性直流输电
限流电阻
反时限保护
预充电
保护定值
HVDC flexible
current suppression resistor
inverse time protection
pre-charging
protection setting value
