Optimum design of high voltage bushings by rational Bézier curves

Purpose - The purpose of this paper is to propose a new approach for designing different parts of a high voltage bushing. It also aims to consider technical and economical criteria for the optimum solution of the design problem.Design methodology approach - A novel method for finding the optimal contours of different elements of high voltage bushings, including ceramic insulator, electrode, and flange angle is presented. The rational Bézier curves are used for defining the surface of the insulators and conductors of the equipment. Then, these curves are optimally adjusted to obtain an appropriate techno-economical solution. The utilized optimization method is the improved bacterial foraging algorithm (BFA) with variable step sizes. In the design procedure, two-dimensional finite element method (2D FEM) is used to calculate the performance parameters in each step of the design procedure. In order to evaluate the performance of the proposed algorithm, optimal design of different elements of a 110 kV bushing using BFA and genetic algorithm is presented, compared, and discussed as well.Findings - The results of this research show that the technical design criteria and economical costs are satisfied by the proposed method. It is concluded that the rational Bézier curves can be implemented for other similar applications and optimal design of other equipment in the electrical engineering field combined with heuristic optimization techniques.Originality value - Bezier curves are used for the first time for bushing design purpose. Two heuristic techniques are also implemented in order to facilitate the comparison and avoid local solutions.