江苏春晨电缆有限公司生产春晨 JBQ电机引接线 引出线,
高电压对绝缘电阻的影响:泄露电流
Influence of high voltage on insulation resistance: leakage current
绝缘材料在恒定电压的作用下,总有一微小的泄漏电流通过。泄漏电流的大小与材料的电导率成正比,与其绝缘电阻成反比。将一块固体绝缘材料两端加上直流电压,则流过其内部(而非表面)的电流随时间的变化趋势如下图所示所示。春晨 JBQ电机引接线 引出线
Under the action of constant voltage, the insulating material always has a small leakage current. The leakage current is directly proportional to the conductivity of the material and inversely proportional to its insulation resistance. When DC voltage is applied to both ends of a piece of solid insulating material, the current flowing through its interior (not its surface) will change with time as shown in the figure below.
固体绝缘材料中的电流i与时间t的关系
The relationship between current I and time t in solid insulating materials
固体绝缘材料中的电流i与时间t的关系
The relationship between current I and time t in solid insulating materials
在接通电源的瞬间,充电电流ic可达到很高值,但迅速进入吸收电流阶段。ia是由于介质内分子、离子等的极化造成的,其大小随时间变化,也受电极形状、介质的种类以及温度等的影响。吸收电流完全衰减至一恒定电流值ig往往需要数分钟以上的时间,有的材料甚至需要几小时至几天的时间,ig称为泄漏电流,它由介质的绝缘电阻所决定。ia与ig的比值达数倍至数十倍。因此,如果在施加电压后马上测电流,并依此来计算绝缘电阻,则此电阻值显著偏小。通常测试绝缘电阻时应以施加电压1分钟或10分钟后的电流来求出。
At the moment of power on, the charging current IC can reach a very high value, but quickly enter the absorption current stage. IA is caused by the polarization of molecules and ions in the medium. Its size changes with time, and is also affected by the electrode shape, the type of medium and temperature. It usually takes more than a few minutes for the absorption current to completely decay to a constant current value Ig. Some materials even take a few hours to several days. Ig is called leakage current, which is determined by the insulation resistance of the medium. The ratio of IA to Ig is several to dozens of times. Therefore, if the current is measured immediately after the voltage is applied and the insulation resistance is calculated according to this, the resistance value is significantly smaller. Generally, the insulation resistan