The paper considers efficiency pertaining to parameter compensation of electric power line, higher efficiency of longitudinal compensation owing to controlled shunt reactors.

 

The paper contains results of the investigations concerning influence of symmetrical and non-symmetrical short circuits at main power network on electric power supply system of a huge oil terminal which is powered by own gas-turbine power station. Calculations have been made in accordance with the IEC and IEEЕ requirements. Estimations for voltage level and distribution of short circuit current in the electric power supply system of the Sangachal oil terminal being operated in parallel with the AzerEnerji grid are presented in the paper

The paper describes a methodology based on the genetic algorithm that permits to automate the process for obtaining optimum rule bases while applying a controller based on a fuzzy logic. Using a specific structure of  a chromosome, a special mutation operation and an adequate fitness function  the proposed methodology makes it possible to select a fuzzy rule base, to minimize a number of rules, rationally to place input sets of fuzzy functions and corresponding arrangement of output singletons in the form of single-element sets. The paper presents an example when the methodology allows to reduce a number of rules by two fold and, consequently, calculative control procedure without any deterioration in quality control.

One of the systems applied for development of programmed logic controller (PLC) software is a CoDeSys programming complex. Its main purpose is to program a PLC and industrial computers in the IEC 61131-3 standard. As a means of PLC programming CoDeSys may be divided in two parts, namely: a programming medium and a programming system. The programming medium is to be operated using a personal computer in the Windows medium. The paper presents rather interesting tool for graphical laying-out of variable values which is used for adjustment of CoDeSys functions. The tool can be applied for adjustment of not only a personal computer but equipment as well even without writing a programme. Built-in visualization system being applied as in the tool medium so in the PLC (with display) and Web makes some operation more convenient. The given paper reveals CoDeSys capabilities using as an example that is a simulation of a D.C. engine control  system with the help of proportional-integral-derivative controller

The paper studies a cascade control synthesis for a two-mass electromechanical object. A cascade synthesis allows to determine a quick action of an electric drive speed regulation loop which is necessary for control of the specified mechanical part. A small parameter method is used in the paper. Calculative expressions for relations of loop frequency characteristics have been obtained in the paper. The paper presents a calculative example with the results of the system mathematical simulation.

A synthesized system is characterized by robustness because variations in object parameters are acceptable if conditions of the system accessory to the given sets are observed.

The proposed method can be applied if an own frequency of elastic vibrations is not very large in comparison with the characteristic frequency of the synthesized system.

The paper presents main theoretical principles that serve as a basis for the developed numerical model of processes pertaining to conjugated heat exchange in the heated buildings. Information on functional capabilities of the developed programme, results of calculations and comparison of the obtained data with the conditions of heat comfort are given in the paper. It has been established that an application of simulation processes pertaining to energy and substance transfer at the design stage is considered as a rather efficient method for provision of the required parameters of a micro-climate and optimization of heat consumption by heated buildings.

The paper demonstrates that in the case of turbulent diffusion flame tongues the burning process of combined multiphase fuel is determined by flow structure and conditions for mixing various types of fuel and distributed oxidizer flows. It has been determined that the ratio of air  supplied for burning through axial and tangential channels governs a shape of the flame tongue, its size and process intensity that allows efficiently to optimize technological parameters.

The paper contains an analysis of calculative dependences for steam-and-water injectors. Discrepancies in calculations and their reasons are shown in the paper. A model of acoustic pressure pumping being realized in the steam-and-water injector is formulated in the paper. The paper presents results of the experiment that  qualitatively confirm the proposed model.

The paper proposes a mathematical model of the equipment unit reliability with due account of operational mode effect and main influencing factors.

Its application contributes to reduction of operating costs, optimization of overhaul periods, prolongation of life-service and rational usage of fleet resource.

The paper gives an analysis of power system in Vietnam. Data on power resources of the country and forecasts pertaining to production and consumption (oil, gas and solid fuel) up to 2020 are cited in the paper.

An analytical method for optimization of water-heating boiler loads has been developed on the basis of approximated semi-empirical dependences pertaining to changes of boiler gross efficiency due to its load. A complex (∂t_ух/∂ξ)Δξ is determined on the basis of a systematic analysis (monitoring) of experimental data and the Y. P. Pecker’s formula for calculation of balance losses q_{2. Th}is complex makes it possible to set a corresponding correction to a standard value of the boiler gross efficiency due to contamination of heating surfaces.

Software means for optimization of water-heating boilers has been developed and it is recommended to be applied under operational conditions.

The paper describes hydraulic tests of discharge capacity and pool conjunction in respect of dam spillway of the Grodno hydroelectric station. The process of ice passage through the spillway dam has been studied in the paper. The paper contains recommendations on safety depth downstream.