An analysis of reliability dependence of back-up relay-contact circuits on multiple failures and probability ratio of opposite-type element failures has been executed in the paper. The paper reveals how to create preference scales of the back-up circuits on a criteria of the highest probability of non-failure operation. 

An efficient methodology, a structural algorithm and a computer program for detection of optimum state of open electrical circuits for discrete parameters have been developed in the paper. The methodology is based on investigation of the total cost elasticity matrix for discrete optimized parameters. The efficiency of the developed structural algorithm is proved by numerical examples. The paper shows that losses in under-loaded electrical circuits can be by two- and even more fold decrease due to setting of optimum nominal transformer capacitance.

Continuous measurement function of relative noise and interference level in the information transmission channel is considered as an important one for controlling parameters of high-frequency signal. The present paper simulates an algorithm for measuring signal-noise ratio in the transmission channel of high-voltage lines which is used in the digital equipment for transmission of relay protection and emergency automation commands of "Strela" complex.

The paper presents methodology for mathematical modeling of power system (its part) when jointly operated with wind power plants (stations) that contain asynchronous doubly-fed machines used as generators. The essence and advantage of the methodology is that it allows efficiently to mate equations of doubly-fed asynchronous machines, written in the axes that rotate with the machine rotor speed with the equations of external electric power system, written in synchronously rotating axes.

The paper considers the influence of impulse unloading of APS power block turbine on its dynamic steadiness. The performed calculations while simulating four various impulse turbine characteristics have shown that the highest effect is obtained while characteristics of APS power block turbine are close to the characteristics of a steam turbine K-300/240. It has been established that an application of standard time interval for emergency automation startup and existing delay in the operation of electro-hydraulic transformer do not allow to influence on acceleration area and the positive effect due to load shedding is reached only due to an increase of braking site. While decreasing time period for control signal supply from 0,2 sec to 0,1 sec it is possible to increase steadiness by 10 %  for impulse characteristics of APS power blocks and by 39,9–42,6 % – for characteristics of the turbine K-300/240.

The paper considers a closed vector control system for induction motor rotation speed of a shipboard tow winch. Structural schemes and transfer functions of the system at control and disturbing influences are presented in the paper. The system with asynchronous motor drive parameters of a shipboard tow winch has been investigated in the paper. It has been revealed that transit process duration of the given system is insignificant. The fact is rather important to prevent accidents in case of vessel towing.

The paper considers potential of power saving by the Belarusian industrial enterprises at transition to cogeneration power supply of heat technological processes.

The paper proposes to improve a standard automatic control double-circuit system while changing a differentiator by difference of complete and incomplete inertial area models of the regulated object and also by using a PID-regulator instead of a PI-regulator and a device for internal disturbance compensations. Methods for structural and parametric optimization of the main regulator and device for internal disturbance compensations that allow to improve the regulation process have been proposed in the paper.

The authors have developed and tested the entire device class that appeared as a result of fundamental investigations of multiphase flows in centrifugal force fields, understanding of process mechanism occurring in them and their mathematical description for optimization. Method for reduction of pressure and steam temperature in vortex pressure-reducing desuperheating plants and steam coolers has been proposed for the first time in the paper.

The paper presents a concrete example that shows comparative characteristics of decentralized and centralized heat supply. It has been shown in the paper that selection of this or that variant of heat supply significantly depends on losses in heat supply networks.