The use of extra-high voltage networks leads to a number of problems with compensation for excess reactive power. An option to avoid these problems is to apply asynchronized synchronous turbine generators, which have a number of advantages over traditional synchronous generators. These advantages are largely manifested under conditions of generator operation in power grids with excess reactive power. Typical examples of such power grids are power grid "Burshtyn Island" and "Power bridge "Ukraine-EU". The article presents the results of mathematical modelling of the steady-state modes for "Power bridge "Ukraine-EU". The mode coordinates are determined under different conditions regarding reactive power particularly with using an asynchronized turbine generator in asynchronous as well as asynchronized modes. The results obtained prove the feasibility and effectiveness of the proposed technical solution.

The widespread applying of electrical grids with voltage classes 330 and 750 kV with powerful units of nuclear and heat power plants creates a set of problems with normal modes ensuring in the Ukrainian energy system. Due to sufficiently great transverse capacitance of such overhead lines, significant amounts of reactive power excess are possible in the system. This phenomenon manifests itself especially in the load reduction hours in the power system through the visible voltage levels deviation at the energy-generating nodes in an upward direction. The application of asynchronized turbogenerators with the ability to work in asynchronous mode could solve the problem of reactive power excesses in the energy-generating nodes during load reduction hours in the power system due to their possibility of deep reactive power consumption. The paper presents the calculated results of the asynchronous modes coordinates for an asynchronized turbogenerator with a capacity 1000 MW based on the parameters of the equivalent circuit, taking into account possible generator stator voltage deviations within ±10%. The influence of voltage deviations on the asynchronous modes coordinates is shown. Due to the obtained characteristics, it is possible to perform engineering estimations of the possible asynchronous mode applying for the asynchronized generator under conditions of nuclear and thermal power plants and taking into account possible voltage deviations.

Modern energy systems feature diversity of elements and combination of processes and phenomena of various physical natures. Mathematical modelling of such systems relies on the tools of the theory of energy circuits. One of the major problems of this theory is formation of the unified system of interrelated variables which allow describing phenomena in circuits of various physical natures. Such a system of variables is underlain by the principle of energy analogy, which is based on the fundamental law of nature-the law of conservation of energy. The relationship between the variables is substantiated on the example of a mechanical circuit, since in mechanics both potential and kinetic energy are most illustrative. Results obtained for a mechanical circuit were then applied to circuits of other physical natures. Energy of magnetic field of the inductor is a counterpart of kinetic energy; therefore, kinetic energy in a mechanical circuit can be defined using generalized inductance. Correspondingly, energy of electrostatic field of the capacitor is a counterpart of potential energy, due to which potential energy in a mechanical circuit can be defined through generalized capacitance.