Optimization of high voltage substations using a random walk technique

A grounding system is on one of the most important points inside transmission and power distribution systems. Poor design methods and simplified calculations can lead to high construction costs and unsafe conditions. This paper introduces a method to design a grounding grid while minimizing time and cost of construction. In this work, computer software has been developed using the equations to solve the optimization problem that considers the parameters of a grounding grid, including geometry, depth, conductor size and the number of grounding rods. The problem is formulated as a mixed integer linear optimization problem. The method incorporates the variables that define the grid characteristics of all possible configurations, including the grid geometry, grid depth, conductor size, and number of grounding rods, size of grounding rods, and, lastly, excavation and installation costs. The optimization problem is subject to safety constraints related to the maximum allowed ground potential rise (GPR), touch and step voltages. The method determines the optimum grid from several possible configurations, so that is a very useful tool for engineering design. A novel optimization technique using a random walk technique to find an optimized grounding grid in a two-layer soil model is proposed. Several examples prove the efficacy of the method.