Application of equivalenting method for electric power grid subsystems in calculating the higher harmonics mode

This article is dedicated to the simplification of calculating the modes of higher harmonics in electric power grids. Non-sinusoidality of voltages and currents is one of the most important indicators of electric energy quality as it affects the operation of almost all kinds of collectors. Power quality depends on the electricity production process, its transportation to the place of sales as well as on the process of its consumption by electrical installations of electricity consumers. In this regard, the actual problem associated with non-sinusoidal voltage is the need to determine the allowable contribution of a particular consumer and power grid to the overall level of non-sinusoidality at the point of common coupling. Therefore, it is necessary to address issues of equivalenting subsystems of electric power grids with a large number of elements in the design scheme and a large number of equations in calculating the modes of higher harmonics to diminish the calculation time, and determine the allowable contribution to the overall level of non-sinusoidality at the point of common coupling. In this context, the aim of this article is to develop a method, algorithm and program for equivalenting subsystems of electric power grids for calculating non-sinusoidal modes. The leading method of research in this paper is the modeling method to optimize the structure of the modeled system, to automate the model formation process and to present the results of analysis in the subsystems. The proposed method of modeling is an equivalent substitution scheme that meets the criteria of equivalence, provides invariability of the original mode studied. The article stuff may be useful in calculating modes of the higher harmonics in electric power grids, the management of which requires solving tasks on a large scale.