Location of compensating devices is determined by various factors: configuration of power supply system, enterprise load schedule, type and length of power lines, parameters of capacitor banks, value of supply voltage. We consider the influence of the above factors on the creation of a mathematical model to determine the location of compensating devices, taking into account the minimum economic costs.

Keywords: compensating devices, reactive power compensation, power system, power grids of industrial enterprises, load schedule, mathematical model, reduced costs

The article considers variants of arrangement of various reactive power compensation devices, the choice of location of which took into account both modes of operation of power grids and voltage levels in the nodes. Mathematical modeling made it possible to form an optimal calculation algorithm based on a multi-criteria approach, taking into account the possible voltage increase at the corresponding substations. However, this approach is accompanied by some increase in active power losses, so the final conclusions should be based on expert procedures.

Keywords: reactive power compensation, mathematical modeling, installation site, power losses, multi-criteria approach, calculation algorithm, power system, substation, compensating devices

The choice of the installation location of compensating devices is determined by various factors that must be taken into account when performing calculations. The location of reactive power compensation devices is determined based on the results of mathematical modeling and the optimal operating mode of individual sections of electrical networks. The paper presents the results of modeling, considers the uncertainties encountered in solving the problem of placement of compensating devices.

Keywords: compensating devices, electric power industry, active power losses, minimum reduced costs, uncertainty, power gain, optimization criteria, electrical node, damage vector, optimization

When determining the locations of compensating devices, it is necessary to make complex calculations that take into account various factors (included in the equations in the form of variables). To get results, calculations are performed repeatedly. Newton's method with coefficients in the form of a Jacobi matrix is widely used. An algorithm for solving the necessary equations by the Gauss method is considered, and the required number of iterations is determined to obtain reliable results.

Keywords: compensating devices, electric power, network state, nodal conductivity matrix, Gauss method, algorithm, Newton's method, electrical nodes, iterations, convergence, algorithm

The article is devoted to the problem of determining the electromagnetic influence degree of electrified AC railways traction networks. The potential, induced by the field, can create a threat to life and health, create conditions for failure of low-voltage equipment, appear as a source of interference. This article considers some approaches to the calculation of electromagnetic field characteristics and gives a critical analysis of the methods used.

Keywords: ice melting, calculated coefficients, selection of optimal parameters, traction power supply system

The article considers the methods of calculation of electric networks when choosing the locations of compensating devices of consumers. The basic network and calculation module of a complex network transformed into a full polygon is analyzed

Keywords: reactive power compensation, optimization, power line, consumer compensating devices, analytical model, reactive load, power system

The Calculations of the electric network modes are based on the determination of electric power losses during transportation.The calculation methods used are based on the Newton method and the Jacobi matrix. The considered version of the calculation (by a number of transformations) with a small number of iterations allows to obtain the same results as when using the Newton method.

Keywords: matrix of nodal resistances, complex resistivity specific increments, losses of electric energy, compensating devices, algorithm, quadratic model, mathematical model

The problem of distribution of compensating devices of consumers between separate nodes of the power system is considered in the article. The analytical model and the algorithm for optimizing reactive power compensation are presented. Criteria of optimality of reactive power compensation are singled out. The account is taken of poorly formalized, technological factors.

Keywords: Keywords reactive power compensation, multicriteria, information uncertainty, consumer compensating devices, analytical model, optimality criteria, normalized factors

Nowadays the rolling stock is equipped with electric drive of high power. Frequency turning regulation, motor protection from overheating and limitation of starting currents are made with the help of semiconductor elements. For reliability improvement of starting and regulating facilities it is reasonable to use low component count. Running through regulating facilities current decrease simplifies electric circuit configuration. The authors propose to use thermal resistors as main elements. In the article the authors examine construct specifications of polycrystal temperature dependent semiconducting resistances of coaxial type and their advantages. There are some theoretical propositions which describe the work of thermal resistors and also some algorithms for synthesis of coaxial type starting devices. The authors made mathematical modeling for starting devices of different types based on thermal resistors. In the article there are some graphical dependences describing starting process.

Keywords: high power thermal resistors, thermal resistors of coaxial type, current density, specific generations of heat, criteria of similarity, starting device, starting current, synthesis of starting devices