基于低通滤波原理的电涌保护器超低残压研究

Study on ultra-low residue voltage of surge protective device based on low pass filter principle

雷电是一种低频脉冲波,频谱主要分布在低频段。通过分析雷电波频谱、Multisim电路仿真和模拟雷击测试,从频域角度研究滤波器参数与残压的关系。试验证明:匹配的LC低通滤波电路并联在电涌保护器后面,能过滤剩余电流的低频能量,降低残压波的陡度,从而获得极低的残压,达到比多台能量配合的电涌保护器更好的保护效果;各类磁心电感在瞬态雷电流冲击时会产生不同程度的磁饱和现象,导致电路失去匹配性,不适合用于电涌保护器滤波电路。

Lightning is a low frequency impulse wave,and its frequency spectrum is mainly distributed in low frequency band.The relationship between filter parameters and residual voltage is studied from the perspective of frequency domain by analyzing lightning spectrum,LC circuit Multisim simulation and lightning test.The experimental results show that the matched LC low-pass filter circuit in parallel behind the surge protective device(SPD) can filter the low-frequency energy of the remaining current and reduce the steepness of the residual voltage wave.Thus it can obtain extremely low residual voltage and give better protection than the SPD with multiple sets of energy coordination.Testing also proves that various magnetic core inductors will produce different degrees of magnetic saturation phenomenon when discharging lightning current,which can cause the loss of circuit matching and is not suitable for SPD filter circuit.