超/特高压分接开关切换试验保护用大容量快速真空开断装置研制

Development of Large Capacity and Fast Vacuum Breaking Device for Switching Test Protection of UHV/EHV Tap Changer

国网分接开关实验室开展超/特高压分接开关频繁带载切换试验时,难免出现极间短路故障情况,如不能快速开断试验回路清除故障,易导致分接开关在油中爆炸安全事故,因此有必要开展大容量快速真空开断关键技术研究及工程化样机研制。文中分析了分接开关切换试验时可能出现的极间短路快速开断工况,设计分析了快速开断装置的结构原理及快速分闸特性优化,解决了快速开断装置高机械寿命和快速分闸特性可分段调节的设计实现。依据上述研究成果,研制了40.5 kV大容量快速真空开断装置工程样机,开展了第三方的短路大电流开断和机械寿命性能验证试验。试验结果表明:快速开断装置的额定短路开断电流为40 kA(叠加80.2%直流分量),额定操作电压下的机械寿命3000次,短路故障快速清除时间≤20 ms,关键性能均满足设计要求,并在分接开关实验室成功投运。该研究攻克了大容量电弧发展与快速分闸特性匹配和大容量电弧能量调控与全相位分布的短路快速开断关键技术,提升了快速开断叠加高直流分量短路大电流能力,解决了频繁开合高电气寿命工程需求难点,实现短路故障快速清除。

The switching test of UHV/EHV tap changers is carried out in the State Grid tap changer laboratory under frequent loads,and it is inevitable that the inter-pole short-circuit fault occurs.If the test circuit cannot be quickly opened to eliminate the fault,it is easy to cause the safety accident of the tap changer in oil explosion.Therefore,it is necessary to research the key technology of rapid opening of vacuum large capacity short-circuit current and the development of engineering prototype.In this paper,the possible fast breaking condition of interpole short circuit in switch switching test is analyzed.The structure principle of fast breaking device and the regulation of fast opening characteristic are analyzed.The problems in design and implementation of the fast switching characteristics of segmented regulation and the fast breaking device with high mechanical life are solved.Based on the above research results,an engineering prototype of 40.5 kV vacuum large capacity short circuit current fast breaking device was developed.The third party short-circuit high-current breaking and mechanical life performance verification tests were carried out.The test results show that the rated short-circuit breaking current of the fast breaking device is 40 kA(superimposed with 80.2%DC component),the mechanical life under the rated operating voltage can reach 3000 times,and the fast clearing time of short-circuit fault was≤20 ms.The key performance meets the design requirements and is successfully put into operation in the switch laboratory.The key technology of short circuit fast breaking with the combination of vacuum arc energy regulation and vacuum arc development and switching characteristics were overcome.The problems in high electrical life engineering requirements for the frequent and rapid breaking device are solved,and the faults of short-circuit and large current are quickly eliminated.