The Study Of Numerical Calculation Of Substation Grounding Grid Resistance And The Transformation Technology

With the continuous improvement of power system voltage levels and increasing the capacity of the system. Ground fault current has continued to grow. Grounding system design to ensure reliable and safe and stable operation of power supply reliability is more prominent. Grounding Network difficult to achieve the original request, how to reduce the economic and effective grounding resistance grounding design is the key issue.This paper introduces two methods of the grounding system, the principle of order and analysis, Principle analysis methods which have circuit and electromagnetic methods. Analysis and comparison of the two methods in the project beyond the differences and the pros.This paper studies the grounding grid design and optimization of network parameters to the vertical grounding electrodes on the improvement. Spacing ranging from the use of the least square method to draw the best network compression ratio. Powstation grounding analysis tool kit to come :Use the quadrate mesh layout and unequal spacing can significantly reduce the touch voltage. unequal mesh layout can significantly lower touch voltage (up to 20%) ,or can save average 20% steel. Therefore, the method of the unequal grounding grid mesh is an economic design.With unequal mesh layout, the improvement to grounding potential rise and and grounding resistance is not very significant. So unequally spaced will only play the role of pressure and can not be used effectively to reduce the grounding resistance.This paper analyzes the relationship of the numbers of pressure conductor and the ground grid parameters, find out conductor of the increase will most improve to reduce the touch voltage ,step voltage followed, and grounding resistance and the grounding potential rise for improvements to the smallest role. Because the shielding effect of the conductor, the conductors of pressure have an optimal value.This paper analyzes the impact of the vertical grounding electrodes and the location to the resistance. find out the vertical grounding electrode utilization factor diminishes with the increase of the number; In order to maximize the technical and economic role, priority should be given to increase the vertical grounding electrodes grounding grid to the brink, not close to the grid center, can reduce the shielding effect of the grounding electrode.Finally, through the transformation of Jingdezhen Yongshan substation grounding example, use the electromagnetic grounding grid model analysis method and finite element analysis of the parameters before and after the transformation to improve the parameter. find out the epitaxial grounding could significantly reduce the step voltage,touch voltage and grounding potential rise. epitaxial grounding is an effective method and prove the correctness of the transformation method.