Research On Optimization Model Of Corrosion Diagnosis For Grounding Grid

Substation grounding system is to ensure the power system operation safe and reliable. Because of the grounding grid are laid underground, bad construction welding, weld, soil erosion, lead to corrosion of lead, or even break. It is important to examine the state of grounding.The grounding grid fault diagnosis optimization model is composed of the electrical network theory, matrix theory and mathematical optimization methods, and then applies to practical problems in the project. This thesis used grounding grid network topology diagram and resistance measurements which between deflectors, combined with shifting the positions of the exciters among the touchable nodes and measures as much as possible for each excitation, utilized the fact that the voltage error of touchable nodes must be within the permissible range, established a new constrained optimization model which target is minimum energy. Finally, used Particle Swarm Optimization and Cultural Algorithm Particle Swarm Optimization to determine the grounding conductor corrosion situation.The grounding grid fault diagnosis optimization model is tested on the example grounding grids with twenty-four branches and forty branches respectively. The results show that:The model which is based on Particle Swarm Optimization use double-layer evolutionary strategy and double-fitness comparative law, after evolving each particle by basic PSO algorithm, use the method which solve linear programming problems for partial update to reduce the particles of non-feasibility, so as to increase computing speed and computational efficiency purposes.The model which is based on Cultural Algorithm Particle Swarm Optimization has better global search capability.The range of estimates which optimal solution most likely appear is given by the excellent individuals of population in the Cultural Algorithm, and then the scope of the small change of the most variables can be determined. This method solved the underdetermined problem which existed in corrosion diagnosis.