电涌保护器之间退耦线圈的选用

从直导线和螺线管的电感公式,推导出直导线与空心和磁芯线圈之间的电感等效公式,根据这些公式可以确定退耦线圈的各项参数.结合国家相关规范,举例计算了几种常用导线的等效退耦线圈的参数,分析了电涌保护器之间退耦装置的作用和选用原则.讨论了两种常见雷电脉冲波形对电感的影响,结果表明:首次雷击波形由于波头陡度较大,电流增大会引起线圈的电感量减小;而长时间雷击波形近似于阶跃波,电流可以认为是恒定的,电流对线圈电感量的影响可以忽略.

Select of Decoupling Coil Between SPDs

From the inductance formulas of straight wire and solenoid,the equivalent inductance formulas betweent straight wire and hollow coil,straight wire and core coil are derived.Based on these formulas the parameters of the decoupling coil can be determined.According to relevant national specifications, several commonly used parameters of equivalent decoupling coil of wires are calculated for example.The role and selection principles of the decoupling device between SPDs are analyzed.The influences of two common lightning stroke waveforms for the inductor are discussed,the results indicate that the lightning stroke current increase will cause the coil inductance decreases because its wave front steepness is larger,and long duration lightning stroke waveform can be similar to the step wave,the current can be considered constant,so the influence of current on the coil inductance can be ignored.