基于液态金属自收缩效应的故障电流触发器

摘要

With the ever-increasing power system capacity of modern ships,fault current level has increased sharply,the action time of electromagnetic tripping protection device can't meet the needs of protection.A GalnSn liquid metal Arc-trigger with merits of fast responding speed,high reliability and self-healing property is proposed which uses arc voltage as actuating signal.A 1 kA prototype has been developed for temperature-rise and pre-arcing tests,the results show that the temperature rise of electrode under rating current is 43 K and the limitation of current carrying ability is mainly magnetic force;the pre-arcing time varies inversely to di/dt,the arc ignited at 1.09 ms under 10.3 A/μs rise rate and has a good reusability.The GalnSn liquid metal arc-trigger can be used in hybrid current limiting circuit breaker to the improvement of reliability and current limiting characteristics.%随着舰船电力系统容量增大,系统短路电流水平急剧上升,传统电磁脱扣保护装置难以满足现代舰船电力系统快速保护需求.提出了一种液态金属型故障电流触发器,利用液态金属GaInSn在短路电流条件下的自收缩效应产生弧压作为动作信号,具有反应速度快、可靠性高、可自恢复等优点.搭建了液态金属型故障电流触发器弧前特性试验平台,设计了额定1 kA的装置样机,进行了温升及弧前特性试验.试验结果表明:液态金属型故障电流触发器额定1 kA通流条件下电极温升仅为43 K,其稳态通流能力主要受电磁力作用约束;液态金属型故障电流触发器弧前时间与di/dt近似呈反比关系,当电流上升率为10.3 A/μs时,触发器弧前时间为1.09 ms.液态金属型故障电流触发器可作为混合型限流断路器的短路电流检测装置,对提高装置可靠性、实现快速限流具有重要意义.