Numerical simulation model of grounding resistance reducing device in substation

How to simulate the grounding resistance reducing device in existing software and how to quantize the effectiveness of for decreasing grounding impedance, have been paid a lot of attention to by power companies and become the research topics for grounding engineers. Firstly, a new calculation method using numerical integration to calculate the grounding system electrical parameters in soil with any number of layers was proposed. This method takes place of the traditional calculation method which uses Taylor series expansion summing to calculate the point charge electric field with continuous integration. Then, based on a lot of field experiment and calculation, a numerical simulation model for new impedance reduction methods is proposed. Experimental data of the grounding modules and ion sticks with different structures from different factories are collected through four seasons and compared by normalization to derive the equivalent radius and length of the conductor by the measured value of grounding impedance. Enlarging the equivalent length is used to establish the model for grounding module, as enlarging the equivalent radius for ion stick. As explosion grounding technique is also a way to let the grid extend into great depths, it is equivalent to vertical grounding electrode with enlarged radius. The equivalent radius is influenced by the geological condition of the soil around the grounding equipments. Deep ground well technique utilizes groundwater in deep well to make grounding electrodes, which can be equivalent to cylindrical grounding electrode model. The numerical simulation model is proved to be valid and practical by actual example.