Lightning fire is an important influencing factor of grassland ecology. It is one of the important ignition sources of grassland fire. The previous researches on lightning fires were mainly focused on forests, but researches on grassland were insufficient. In this paper, the impulse voltage generator was used to evaluate the breakdown characteristics of grass bed. The relationship of breakdown voltage to moisture content and bulk density was obtained. Based on the impulse current generator, an artificial lightning ignition prediction model of impulse current was derived. Results show that the breakdown voltage of grass bed decreases rapidly with the increase of moisture content. With the increase of peak current, the total lightning energy increases, while the heating efficiency decreases.

雷电是影响草原生态的重要因素。它是草原火灾的重要点火源之一。以前关于雷火的研究主要集中在森林上，但是对草地的研究还不够。本文使用脉冲电压发生器来评估草床的击穿特性。得到了击穿电压与水分含量和堆积密度的关系。基于脉冲电流发生器，推导了脉冲电流的人工雷电预测模型。结果表明，随着水分含量的增加，草床的击穿电压迅速降低。随着峰值电流的增加，总雷电能量增加，而加热效率降低。