Research and Investigation of High Frequency Profile of Step and Touch Voltages Due to Fragmentation of the Grounding Grid

Abstract

The increasing demand and the benefits of electricity energy have led to the creation of huge power plants, so high voltage substations are necessary for electrical energy. Installing different small power plants to prevent consumption in different parts of a country requires reservation units and high costs for repairs, maintenance and fueling. The necessity of these substations can be searched in the lack of uniformity of different costs, the costs of generating electrical energy, the lack of consumption centers near power plants, and generally the existence of a national grid and the possibility of timely disconnection of the faulty parts of the power grid. The priority in the rehabilitating of a strong substation is to meet the system's operation needs. In all electrical installations, especially in industrial complexes, land connectivity is one of the most important and fundamental measures to protect individuals and equipment and improve the performance of the system. The purpose of ground equipment system is to potentialize the metal body of all electrical equipment with the ground to prevent electrocution and protect personnel. This type of connection is not normally a current carrier, but if one of the phases of the device is connected to the fuselage, the fault current enters the ground through this connection and closes its path through the trans neutral or the generator connected to the ground. Earth networks due to different structures of the earth in different regions may cause problems over time, one of them is the fragmentation of the earth's network due to rot of conductors or due to overvoltage. In this research at different and high frequencies, we use 3 frequencies of 50, 100 kilos and 1 MHz, to check the ground network factors and the security of equipment and people in high voltage substations, we use CDEGS software which is a specialized program for designing and investigating the earth network.

Objetivo: Research and investigation of high frequency, profile of step and touch voltajes of grounding grid.

Metodología: Design and modeling with Comsol software.

Resultados: As the frequency increases, both the step voltage and the touch voltage at the corner points increase more.

Conclusiones: By comparing the voltage profiles based on the simulation results, it was found that by increasing the frequency of the contact voltage in each profile and mesh, it is noticeably increased. The point to consider after reviewing the simulation results is that by increasing the frequency of both step voltage and touch voltage in the corner points, they are more increased than other parts.