10kV自然换流型混合式直流断路器中真空电弧电流转移特性研究  

Researches on Commutating Characteristics of Mechanical Vacuum Switch in 10k V Natural-commutate Hybrid DC Circuit Breaker

作　　者：吕纲[1] 曾嵘[1] 黄瑜珑[1] 陈政宇[1] 

机构地区：[1]电力系统国家重点实验室(清华大学电机系),北京市海淀区100084

出　　处：《中国电机工程学报》2017年第4期1012-1020,共9页Proceedings of the CSEE

基　　金：国家863高技术基金项目(2013AA050104)~~

摘　　要：围绕应用于?10kV直流配电领域中的自然换流型混合式直流断路器的电弧电流转移特性展开研究。开断过程中,机械开关支路在没有辅助换流装置的情况下,需要在真空电弧电压的作用下实现电流向主关断支路的转移。文中建立了真空电弧电流转移的数学模型,确定了电弧电压、转移回路电感电阻参数、电力电子支路的导通压降是影响真空电弧电流转移的主要因素。实验方面首先对具有不同触头结构及材料的真空灭弧室进行了电弧电压测量,实验表明真空电弧电压可以同电力电子支路进行配合;在此基础上,采用IGBT作为电力电子支路开关,进行真空电弧电流向电力电子支路的转移实验,并研究了回路电感电阻参数对于转移特性的影响;最后,设计实现了10kV自然换流型混合式直流断路器,并对开断进行了实验:真空灭弧室电弧电流在1.5ms内完全转移到电力电子支路,关断电流3.6kA、关断过电压21.4kV,验证了该方案的可行性。This paper has focused on the commutation characteristics of mechanical vacuum switch in naturalcommutate hybrid DC circuit breaker（NHDB） in ±10kV flexible DC system. During the interruption process of NHDB, the current in mechanical branch will be commutated to the power electronic branch under the action of the mechanical vacuum arc without the use of auxiliary switch. At first the model of NHDB was proposed, which make it clear that the arc voltage, induction and resistance of branches, the forward voltage drop of the power electronic devices are the main factors behind the commutation process. Special experiment has been designed and conducted to measure the arc voltage of single vacuum chamber with different contact structures and materials. Based on the tests results, the arc voltage of mechanical vacuum switch is enough to make sure the current be commutated to the power electronic devices branch in middle-voltage hybrid DC breaker. Then IGBT was used as the power electronic branch in parallel with a mechanical vacuum switch branch. Current commutation process was experimented and the impact of induction and resistance of the commutation loop was discussed. Finally, based on the results above, a 10 kV NHDB prototype was designed and tested. During the current interruption process of the prototype, the peak current of 3.6kA in the mechanical vacuum branch was commutated to the power electronic device in 1.5ms and was successfully interrupted with overvoltage of 21.4kV.

关 键 词：自然换流型混合式直流断路器 真空电弧电压 电流转移特性 

分 类 号：TM71[电气工程—电力系统及自动化]