Mathematical model for calculation of thermal conditions of oil transformers.

Abstract

When operating electrical equipment and designing, there is always a need to solve the heating problem and cool it, namely the most vulnerable structural element - winding insulation. Issues related to the calculation of thermal conditions are the least developed area of the industry to create modern electrical equipment. The methods they are solved have an error of more than 10%, which is unacceptable. Therefore, the development of methods for mathematical modeling of the thermal regime of oil transformers using Simulink is relevant. The authors carried out a comparative analysis of existing methods for calculating the thermal regime of oil transformers. Based on our study, we propose classifying these methods into four groups. It has been proved that these models are challenging to analyze and have an error of more than 10%. We offer a model of thermal processes in oil transformers. The scientific novelty of the model is that for the first time, the object-oriented software module of the Simulink environment of MATLAB was used to describe the thermal modes of operation of oil-filled transformers. The simulation process was visualized using an oscilloscope (Scope) and a plotting unit (XY Graph). The upper input port is used for argument values, and the lower input port is used for function values. The main results of the study: - the existing methods for calculating the thermal regime of oil transformers were analyzed - the system of Lawrence equations was solved by the methods of mathematical modeling. - based on the study of the behavior of a dynamic non-autonomous system using Simulink methods, a convention model applicable to the description of the thermal mode of operation of oil transformers and other modern electrical equipment was developed. The proposed model for calculating the thermal operating conditions of oil-filled transformers are characterized by functionality and the possibility of using the results and the model itself in the design of modern electrical equipment.