The paper considers damping of vibrations in interchange power of interconnecting transmission lines. Influence of natural and supplementary regulation parameters on the character of transient process is shown in the paper.

The paper contains recommendations for elimination of maximum interchange power deviation in the transient process.

The problem pertaining to maintenance of current protection sensitivity against inter-phase short-circuits is considered in the paper. The paper proposes a principle for execution of adaptive microprocessor current protection that makes it possible to increase sensibility factor and lower restriction on application of the given kind of protection.

Monitoring process of measurement reliability in respect of variables that characterize operation modes of power units is investigated in the paper. Control algorithms based on the minimax criterion have been developed. These algorithms take into account the uncertainty in the notion of measurement reliability, the probability distribution laws for the variables under control, and the values of monitoring errors.

It is proposed to characterize power efficiency of combined lighting systems with automatic control by a coefficient that is specifically determined. Conclusion about the expediency of application of the lighting devices with various luminous intensity curves in the lines parallel to light openings has been made on the basis of the calculations. In order to improve efficiency of such lighting systems it is recommended to have a unified approach to development of artificial and daylight illumination sub-systems and automatic control lighting systems.

Mathematical model of power consumption for technologically completed and non-completed oil pipe-line sections with poor operational stability has been developed on the basis of daily indices concerning oil transportation regimes. The model permits to take into account tendencies in power consumption under various time prediction cycles and ranges of oil freight turnover, changes in the bulk and characteristics of the transported oil, configuration and design parameters of oil pipe-line.

The paper analyzes an influence of operating parameters of the Armenian Power System (PS) on the value of technical power losses in the 110–220 kV transmission networks. Methods of regression and variance analyses are used in this paper. A number of calculation experiments have been carried out and such factors as power supply of the Armenian Power System, power flow between the Armenian and Iranian Power Systems, total load of the Armenian Power System, power export from the Armenian Power System to the Georgian Power System have been taken as the influencing ones. The obtained regression equations reflect the most common tendencies of the Armenian Power System behavior and allow to draw a conclusion regarding the nature of its operating parameters’ influence on the value of technical power losses in transmission networks that means to restrict the field of solution search, directed to the reduction of technical losses.

The paper considers a DC-to-DC converter as an object of automatic control system. It has been shown that the given device has strikingly pronounced resonance properties. Resonance frequency of the step-up converter depends on control signal duration. Application of internal inductance current feedback and output voltage feedback with PI-regulator permits to obtain appropriate qualitative transient indices.

The paper reveals an accelerating circuit for electromagnet operation with the help of an additional resistor R that is shunted with a capacitor C. Resistor R is connected in series with the electromagnet winding. The possibility of the circuit optimization has been substantiated with the purpose to limit the final speed with which a movable part of the electromagnet reaches a limiter. Such circuit may find its application in relay protection.

The paper contains estimation of threshold sensitivity of correlation measuring methods in light-emitting diode and laser devices for continuous control of boiler smoke gas composition. Proposals are given to eliminate influence of dissipation losses and instability of optic and electronic path parameters on the results of control process. It is shown that application of non-dispersion and modified correlation methods for measuring CO and O₂ concentration and infra-red light-emitting diodes lasers make it possible to conduct continuous control of smoke gas composition. This control is made by means of smoke flow exposure without taking samples and ensuring small errors and operational reliability.

Computer calculations of tensile and compression stresses along an ingot length of 250´300 size for a group of industrial steel are conducted on the basis of the «ProNRS-2» computer system. New data about nature of surface stresses in industrial ingots of 40Х, 70К, 2С45, 20ХН3А steel grades are obtained. It is shown that the highest level of tensile stress is observed in the case of an ingot of 40X steel grade and the lowest level of this parameter is fallen at an ingot of 70К steel grade.

Problem concerning improvement of operational efficiency of thermal power stations by intensification of heat transfer in various elements of equipment is of current concern in power engineering. The paper contains a large body of experimental data and some proposals are given how to apply them for operating equipment at thermal power stations.

Results of investigation of capillary structure properties used in evaporation – condensation devices are presented.

Constructive solutions for intensification of heat transfer in evaporation and condensation heat exchangers are offered. The obtained heat transfer experimental data at film-type vapor conden-sation are generalized in criterion form.

Description of general rule of heat and mass transfer processes in miniature heat pipes with three various capillary structures at wide range of operating parameters is given in the paper.

The purpose of the proposed investigation is a mathematical formulation and solution of the problem concerning selection of operating parameters of heat- and mass transfer processes while using numerical methods. The solution of the problem makes it possible to calculate changes in function describing state of the controlled media in order to obtain the desired distribution within minimum time. Results of the given paper are applicable for description of drying, blowing-up and other processes