多级电涌保护器对负载有效性试验分析

Experiment Analysis on the Effectiveness of Multi-Level SPDs to Load

针对多级电涌保护器(SPD)安装在电源线路时可能对负载电压起到抑制作用,而导致SPD达不到预期的有效性保护的问题,通过组合波发生器(1.2/50μs、8/20μs)模拟雷电流,对负载分别为阻性、容性、感性时,特性阻抗值相同、长度不同的RVVP电缆做冲击试验,研究负载与RVVP电缆特性阻抗匹配关系及波电缆中的折反射现象,分析电缆的长度与不同特性负载的关系,得出当负载为阻性时,多级电涌保护器的有效防护距离与电阻值呈负相关;当负载为容性时,多级电涌保护器的有效防护距离与电容值呈先负相关后正相关;当负载为感性时,多级电涌保护器的有效防护距离与电感值呈负相关。具有一定的实用价值。

The installation of Multi-level surge protector in the power distribution line may suppress the load voltage. As a result, SPD may not reach the desired protective effects. Through the impulse experiments, the simulated lightning currents generated from combined wave generator（1.2/50 μs, 8/20 Us） are applied to the resistive, inductive and capacitive loads connected with the RVVP cable of the same characteristic impedance and different length. The match of characteristic impedance between load and RVVP cable, the reflection and refraction of waves in the cable are researched respectively. Based on the analysis on the cable with different length and load, it can be obtained that when the load is resistive, the effective protection distance of the multi-level surge protector is negatively correlated with the resistance value; when the load is capacitive, the effective protection distance is negatively correlated with the capacitance value at first and then takes on a positive correlation; when the load is inductive, it is negatively correlated with the inductance value, which has a certain reference value in the practical application.