舰船电网电气传输距离短,短路电流沿线路衰减很小,高上升率的短路电流往往会使上下两级开关同时动作,导致选择性保护失效。本文在舰用300A和1000A塑壳开关电磁脱扣器特性曲线基础上,分析了舰船电网电流原则选择性保护失效的原因,提出了一种基于高速限流重合闸装置——HLB的选择性保护方法。故障时,通过HLB的快速限流,避免了上级开关动作,故障支路开关跳开后,HLB快速重合闸恢复对无故障支路的供电,实现系统的选择性保护。实验证明该方法可以将预期峰值100kA,时间常数为7ms的短路电流限流在15.4kA,故障切除后50ms内重合闸恢复对非故障支路的供电,实现电网的选择性保护。
The fault current rarely decreases in the short-line on ship net,and gets high rate of rise.The main switch acts together with the branch switch,and consequently,the selective protection way fails.Due to the electromagnetism trip's curves of 300 A and 1000 A plastic switch used on ship,the paper discusses the failure of the select protect way ground on current.A selective protection way,based on High Speed Current Limit Superposition Breaker(HLB) is introduced.The experiment in which the peak value of short-circuit current is 15.4 kA with prospective peak current 100 kA and time constant 7 ms and the switch recloses after the recovery within 50 ms verifies this way can select protect the DC power network.