Calculation And Improvements Of Large Grounding Grid Surface Potential Distribution

Into the 21^st century, more and more extra-high voltage and high-voltage power grid have been building by the National Grid. Then the power system voltage level got higher and higher, which makes the system of the short-circuit current increasing. So it makes a higher requirement for the designer to design and measurement of the power system. In the past, we determine whether the ground grid safety or not by measuring the ground resistance, which method is mainly used to evaluate. But in fact, the risks when the ground grid is flowing a high current were the potential distribution, the step voltage and the contact voltage. In this paper, students with previous study, which has studied the simulations that how to measured the potential distribution and the potential gradient in an irregular ground grid spacing distribution range, I improved the program. And the simulation could get more accurate measurement results.In this paper, an improved program could calculated any structure of the grounding grid. Through the software of Origin to analyze the results obtained, it could draw the surface potential distribution of the grounding grid, which can be more intuitive and clear reflect the whole surface potential distribution. If we got it, we can analyze of different grounding easily.The symmetrical distribution of the network is calculated to prove the correctness of the program. The calculation of the irregular structure network show that all kinds of irregular network is applicable to calculate. The calculation of the network with long conductor proved the rationality of the improved program. Using a mathematical model to find error in the program and improve it, we can improve the accuracy of the program's operation.Finally, I use this program to calculate a large-scale substation grounding, and analyze using Origin software, draw the surface potention distribution of three-dimensional map and gray scale image. By comparing these two sets of data and graphics, it could show the rationality of the improved program. By comparison with the measured data proves the correctness and rationality of the program. Finally, it work out the calculation and analysis methed is more direct and effective analysis whether or not the rational of grounding grid layout and security. This methed could give some direction to valuate the grounding grid's safety.