Analysis And Application On Measuring Method Of Grounding Resistant For 500KV Substation

Under the background of the rapid development of society and economy in china, the construction of power systems and electronic power project has been developing rapidly to meet the growing demand for electricity. This has brought a higher requirement for power supply reliability and safety of network. More and more attention has been attracted to the grounding grid security, because of it played a vital role in the lightning overvoltage grounding accident, operating overvoltage grounding accident and protection action of the grounding. Since the 500kV power grid had become the backbone of power transmission network in Shandong province, it was the most important to protect the safe operation of 500kV substation grounding grid.At present, we mainly test ground regular to get the health status of the substation grounding grid in Shandong province, and there are too many different methods we can use for testing, such as the straight-line method, the angle method, the far-away method and so on. Meanwhile, it also has a wide range because of interference factors in measurements. In this article, we will go through some research to find the best way on testing, that we can get the right measurements fast and accurately.In this paper, we will introduce the basic concepts of grounding first, including the classification of grounding, the form of grounding, the common ground grid corrosion failure, and etc., this article will also be discussing the common ground resistance measurement methods and principles, as well as a variety of sources of error in measuring the presence, and the approaches to avoid such errors. To be noticed, all these discussions are based on the theoretical foundation. Finally, after a practical application to three test templates including Weifang 500kV substation, Jinan 500kV substation and Binzhou 500kV substation, we are able to run some practical measurements and data analysis for a variety of earth resistance measurement method. By comparing the data collected from these experiments, we can get the concludes that the far-away method is widely applicable and an relatively accurate test method to measure ground resistance from the 500kV substations in Shandong, while it will depend on the applicable conditions of specific site when use other methods.Although this article is only a guide for the practical application, as long as only one single type of measuring instrument has been used in the test which reveals the obvious limitation. It has important reference value and universal significance for electricity staff to do ground resistance testing, that the analysis we made which runs from base theory to actual application, from principle to practice, as well as the data collected from real experiment.