浪涌抑制与电磁兼容

浪涌是低压电源线中最频繁发生的过电压和电流波动现象.研究电源线中的浪涌时不仅要分析它的电压幅值高低,还要分析它的电流和能量.电源线中浪涌抑制需要从过电压保护和电磁兼容两方面考虑.作者通过计算标准测试浪涌的波形和频谱,指出浪涌危害的主要原因和保护低压电源线与其上电子设备电磁兼容性的措施.最后计算了在交流电源中用氧化锌压敏电阻对浪涌进行限幅和泻流的一个实例.

SURGE SUPPRESSION AND ELECTROMAGNETIC COMPATIBILITY

Surges are the over-voltage and over-current phenomena that occur commonly in low-voltage AC power line. To research the surges in AC power line, the voltage amplitude of surge should be analyzed and the current and energy should be also analyzed. In the suppression of surges in low voltage power lines the over-voltage protection measures and the electromagnetic capability (EMC) of the electronic devices should be considered. Through the calculation of the waveforms and the baud chart of standard test surges, the main reason of the damage in low voltage power line caused by surges is pointed out, the measure for both secure operation of the low voltage power line and the EMC of the electronic devices connected to the power lines are given. Finally, a practical calculation example of clamping the voltage of low voltage power line under the surge and effusion surge current by metal oxide varistor is given.