Testing of current dispersal regularity of common tower grounding devices

Abstract

The impulse current dispersion of the tower grounding system will affect the impulse grounding resistance of the grounding device, according to the grounding device characteristics of the impulse current dispersion to design and optimize the structure of grounding system can improve the grounding effect. Using the field tests of equal scale reduced model, the variation law of impulse current dispersion is analyzed from the common tower grounding system. The experimental results show that when the total volume of materials is fixed, the smaller the grounding device radius is, the larger the surface area of the dispersion is, and the smaller the power frequency ground resistance is. Normally, the impact factor of the grounding device is less than 1, because of the spark corona effect of the grounding device under the high frequency impact within 30 kHz, the inductance effect is much larger than the impedance effect, the impact resistance is too small. With the increase of soil resistivity value, the grounding impedance reflected by impact characteristics is obviously increased. The law of impulse current dispersion caused by simulation test is helpful to improve the effect of grounding device.