Substation Grounding Improvement And Suppression Of Electromagnetic Disturbance To The Cable

In recent years, with the rapid development of high voltage power generation, the voltage level and capacity of the transmission are also improved quickly. This leads to an increase in the current amplitude of the fault current in power system. In order to meet this situation it is necessary to improve the performance of grounding grid system. But it is limited to the construction cost and the natural environment, grounding grid design and construction couldn’t blindly to expand grid area to solve all questions about grounding grid, Under the condition of ensuring the safe operation of the substation, the economical and efficient construction of the substation grounding grid is a research hotspot.In the past, the research about station grounding grid is too ideal, and it is not suitable for the high voltage level of transmission line. In these research a lot of factors has been neglected, this method leads the conclusion is not suitable in the real construction. Due to the horizontal direction of the grounding grid area is not suitable for the new requests, a new method of grounding grid to develop in depth has been a good solution. The grounding grid performance has been improved by using vertical grounding rods. In this paper, the vertical grounding rods also been a part of research.In the previous grounding grid performance evaluation, grounding resistance, touch voltage and step voltage as the ultimate measure of target. However, the increase of the number of secondary equipment in the substation, and the increase of the sensitivity of the secondary equipment leads a higher request about secondary equipment. In this article the secondary equipment interference ability has been a part of grounding grid performance.In this paper, the equalizing belt layout scheme of square and rectangular grounding grid is analyzed in the uniform and non-uniform soil environment. The research object is to equal all station’s touch voltage. Subsequently introduced into vertical grounding rods on grounding grids is second time optimization, directly reduce the ground resistance of grounding grids.The using of vertical grounding rods has been analysed include position, root length and number of grounding grid connected impedance effect.At last, the two methods are used to optimize the grounding grid and the secondary cable disturbance voltage is introduced. It is proved that this method has practical engineering significance and obvious optimization effect.