高压电压互感器中电容分压器随温度变化数学模型的研究

通过对高压电压互感器分析,建立了基于高压绝缘理论的电容分压器随温度变化的数学模型;通过对数学模型分析可以看出:影响电容分压器精度的关键在于电容器的稳定性和精度,而影响电容器精度的诸多因素中最重要的是温度;电容值变化的相对误差与圆柱筒的半径、温度、膨胀系数、圆柱筒的壁厚均有关系且随着它们的增大而增大.因此,选择低膨胀系数的金属材料和适当的圆柱筒的壁厚是提高圆柱形电容器精度的关键,从而为高压电容分压器的设计提供了理论依据.

Study on a Mathematic Model of Capacitor Voltage Divider Varied with Temperature in the High Voltage Potential Transformer

Through the analyses of high voltage potential transformer,a mathematic model based on high voltage insulation theory of capacitor voltage divider varied with temperature are built.As can be seen by this model: The key effect to accuracy of capacitor voltage divider lies in its steady and precise;whereas,among many factors,temperature is the most important ones which affects the accuracy of capacitor;The relative error of capacitance varies with radius of cylinder,temperature,expansion coefficient and the thickness of cylinder,and increases following with them;So,the key to enhance the accuracy of columniform capacitor is to choose metal material of low expansion coefficient and proper thickness of cylinder;Thereby,it provides a design for capacitor voltage divider in theory.