• Energy Research

The paper discusses the problem of drying electric motors in a humid environment. The study considers the influence of oven, current, electroosmotic, convective-electroosmotic drying methods on defect formation in electrical insulating materials of electric motors. Thermal oven drying destroys the insulation system of electric motors for an order of magnitude higher than other methods and has a lot of negative consequences. The electroosmotic and convective-electroosmotic drying processes do not have disadvantages of thermal drying methods, or these disadvantages are kept to a minimum. It is shown that electroosmotic and convective-electroosmotic drying result in a uniform distribution of moisture content in the volume of electrical insulating materials. This reduces the likelihood of dangerous stresses and subsequent cracking. Electroosmotic and convective-electroosmotic drying have little effect on defect formation processes in the insulation system of electric motors and, thus, almost do not reduce the service life of electric motors.

We consider the issues of modeling power lines using a self-adjusting mathematical model which allows analyzing the lines operating modes while tracking instantaneous values of parameters. The obtained model can be used to build high-speed protection against phase-to-phase faults in power lines with a voltage of 10-35 kV, which have a small length.

Abstract A method is proposed for estimating the parameters of electric motors. It has new properties that increase the sensitivity and efficiency in terms of detecting internal short circuits in the windings of controlled electric motors in non-stationary conditions.

We consider the issues of modeling power lines using a self-adjusting mathematical model which allows analyzing the lines operating modes while tracking instantaneous values of parameters. The obtained model can be used to build high-speed protection against phase-to-phase faults in power lines with a voltage of 10–35 kV, which have a small length.

The article presents measure to optimize the operating modes of power transformers in order to minimize losses of electrical energy. The influence of actual voltage and service life of power transformers on electric power losses is shown. It was proposed to determine the economic capacity of power transformers taking into account the indicated factors, as well as taking into account the time of transformer switching on into the electric network and the form of the load schedule.

The existing methods for calculation electricity tariffs for enterprises are analyzed numerically. The efficiency of diesel generators use for power supply was estimated using a real object as an example. A methodology has been developed for choosing the optimal price category, based on the schedule for consumption of electrical energy of a particular enterprise, taking into account introduction of its own generation in the 0.4 kV network. It is shown how to get the maximum benefit using one of the most affordable and autonomous power sources, taking into account the peculiarities of tariff setting for electricity.