OPTIMIZATION OF DESIGN PARAMETERS OF AUTOTRANSFORMERS IN ICE MELTING SCHEME WITH NON-INDUCTIVE CIRCUIT ON 6-10 KV OVERHEAD POWER LINES

Purpose. The purpose of the paper is to determine the basic electrical characteristics and to develop a calculation method and algorithm for optimizing the design parameters of autotransformers intended for use in a melting ice scheme with a non-inductive circuit on 6-10 kV overhead power lines. Methodology. The development of the technical and economic model and the method for calculation of the design parameters of the autotransformer for melting ice is performed on the basis of a systematic approach. Optimization of structural characteristics of autotransformers is carried out using a combined algorithm based on the spatial grid method, adapted to the case of a mixed space of discrete and continuous independent variables, and the specifics of the technical and economic model of the autotransformer. The proposed combined optimization algorithm is implemented in the Delphi environment. Results. Based on the required specific melting power, the main electrical characteristics of autotransformers intended for use in the meltingicr scheme with a non-inductive circuit on 6-10 kV overhead lines, which were the basis for optimizing their design parameters, have been calculated. The technical and economical model of autotransformer for melting ice, which is defined by nine independent variables and describes its cost and technical parameters, is developed. On the basis of the obtained electrical characteristics, optimization of the design parameters of a series of autotransformers is carried out, which includes three standard sizes, differing in maximum length of the transmission line. Originality. A method of calculation of structural parameters of autotransformers for ice melting is proposed, the peculiarity of which is the use of the criterion of the minimum of the cost of the active part and taking into account the conditioned by the circuit of connection of the autotransformers the technical restrictions of errors on the value and angle of secondary current, which are important from the point of view of ensuring the permissible deviation of the specific power of melting ice. Practical value. Optimal correlations of geometrical sizes and electromagnetic loads of autotransformers for ice melting, their cost indicators, as well as the main design characteristics of the magnetic circuit and windings are established. Results of design calculation of autotransformers are sufficient for introduction of their serial production in industrial conditions.