The paper contains a brief analysis of protection devices applied for various elements of distributive networks with a single-way supply. Advantages and disadvantages of maximum current protection with current-temporary characteristics which are independent and inversely dependent on current and some new possible methods for improvement of current protection sensitivity of distributive networks are considered in the paper.

A principal circuit diagram has been developed for an autonomous power system on the basis of renewable energy sources – solar and accumulator batteries.

Due to the usage of a dc pulse converter, a dc converter (interrupter), an IGBT module inverter and a single-phase matching power transformer it is possible to achieve an effective sectioning of constant voltage and their inversion with minimal energy losses.

Efficiency factor of the proposed converter installation exceeds 90 % and power factor is close to unity.

The paper considers an improvement of crane equipment operation, particularly, its travel mechanisms  at the expense of updating currently widely applied electric drives with squirrel-cage induction motors. The authors propose to use a pulse voltage regulator based on IGBT transistors with additional function of quasi-frequency control ability as a soft starter which has higher technical-economic indices in comparison with existing thyristor starters and prove its application by the results of their investigations. Application of such device in  electric drives of crane travel mechanisms where there is no need to carry out a technological speed regulation, allows to make soft starting, soft braking and accurate stoppage of an electric drive at the cost of  squirrel-cage induction motor transition to retarded speed prior to stoppage which is ensured by quasi-frequency motor control.

The paper proposes a method for determination a permissible duration of short intermittent overloads of power transformers that permits to avoid non-permissible over-heating of winding insulation and fully utilize overloading transformer ability.

 The paper considers reliability criteria characterizing wind electrical installations (WEI) as restorable systems. It has been shown that the main criterion influencing on reliability of WEI electric supply is a restoration time. Evaluation of restoration time influence on WEI control time has been made in the paper. The paper presents methodology for determination of optimum period  of  WEI control. The optimum period of the scheduled control for WEI of NORDEX-type No.54 has been determined in the paper.

Methodology for distance detection of ground fault point in the networks with an insulated neutral for cable lines with distributed loads and parameters of emergency mode have been developed in the paper. The paper proposes an algorithm of automatic one-phase ground fault in the urban cable distributive networks with indication of damage point. The possibility of centralized damage detection is considered in the paper.

The paper contains a stress analysis in the field of elastic and elastic-plastic wall state of a cast iron module industrial recuperator of high-temperature technology furnaces applied in blank and mechanical assembly production at machine building enterprises.

The paper presents a mathematical model and numerical solution of a problem in 2D-heating of multi-layer bodies. работе приведена математическая модель и численное решение задачи в двумерной постановке нагрева  2D –heating многослойных тел. Displacement of phase transformation front along layer section is taken into account in  the paper.

The developed mathematical model is applied for calculation of temperature fields in the process of obtaining multi-layer products with special properties.

Such products with the given operating characteristics can be applied in new innovation technologies of power and machine building engineering.

The paper considers problems of modern methods for  calculation of designs and materials of nuclear power. A model of numerical analysis for stress-strain state of fuel pins in the NPP active zone is proposed in the paper. The paper contains simulation concerning a fuel core section of a nuclear reactor heat-generating element with subsequent solution of a temperature and thermoelastic problem in computer program complex FEA ANSYS Workbench 11.0. All the obtained results have passed through checking procedure.

The paper presents results of physical and numerical simulation of aerodynamics of a cyclone heating device. Calculation models of axial and radial flow motions at various outlet diameters and also cyclone flow motion trajectory have been developed in the paper. The paper considers and compares experimental and calculated distributions of tangential and axial component of full flow rate. The comparison of numerical and physical experimental results has revealed good prospects concerning usage of CFX ^®10.0 programming complex for simulation of aerodynamics of cyclone heating devices and further improvement of methodologies and their aerodynamic calculation.

The paper considers problems concerning optimization of gas turbine operational modes at varying loads due to regeneration application. The possibility pertaining to increase of operational efficiency gas-turbine units at various modes is shown in the paper. The efficiency can be achieved due to an increase of regeneration rate while reducing consumer’s heat load.

The paper provides a methodology and experimental investigation results of the process pertaining to pressure impulse spreading due to an underwater explosion of hydrogen-oxygen gas mixture in a cylindrical chamber which is open from the bottom, closed cylindrical and spherical chambers with elastic covers. Comparison of the experimental investigation results with theoretical calculations is given in the paper.