Development Of Tower Grounding Device's Impulse Ground Impedance Measurement System

With the development of power system, the request proposed to electrical power system's grounding is becoming higher and newer. Grounding problem in power system is more and more important. There are a lot of damage by lightning on transmission line towers, but now ground impedance measurement only can measure industry frequency ground impedance, but rarely measure impulse ground impedance, so it is very necessary to research a new method of measuring tower impulse ground impedance.This paper has analyzed the common structure and characteristics of the tower grounding device, and has calculated the transient voltage of the top of the tower when lightning on transmission line towers. Embarked from the theory has proven the impact ground resistance survey importance.This paper has presented a new method of measuring ground impedance by generating impulse current signal. Based on simulation, this paper has designed the impulse ground impedance measurement system, which is operated easily and fit field project application.In the last part of this paper, through using the impact earth resistance measurement system's laboratory test and the survey experiment which on some transmission line poles and towers, and analysis the theory of the tower grounding device's impact characteristic. Experimental results indicate that the impulse ground impedance value measured by this measurement system is true and valid, and this measurement system fit actual project measurement.