Study of Partial-Phase Steady-State Operation Modes of Phase-Shift Transformer with Hexagonal Circuit and Regulating Autotransformer

The scope of the work was the study of the phase failure operating for the new FACT’s type phase-shifting device, intended for the flexible connection of AC power systems. The mathamatical model has been developed for conducting this study. The device contains the main phase-shifting transformer based on hexagon circuit with additional regulating autotransformer, this creates the possibility of circular regulation of phase shift angle between connected systems. The model includes two 6-winding three-legs transformers, for which two sets of parameters can be independently set based on the data for the short circuit and no-load modes. The data for the direct sequence parameters is usually provided by the transformer manufacturers, and the data for the zero sequence parameters could be obtained upon additional request. As a result of modeling, the vectors of the voltages and currents were obtained in all windings in the investigated modes with supply source phase failure. This makes it possible to analyze the admissibility of such modes and estimate the need for taking special measures of protection against them. It is shown that the voltages on the windings of the main transformer insignificantly depend on the connection mode of the regulating autotransformer, while the pattern of currents distribution in the windings of the main and regulating transformers to a large extent is determined by said connection mode of the autotransformer. The presence of perceptible zero-sequence current flowing through the grounded neutrals of the power supply source and load is noticed. This fact is connected with the release of insignificant magnetic flux from the magnetic circuit in the surrounding space

Selection of Best Power Supply Source for Telecom Towers in Remote Areas

Installation of telecom towers in remote areas especially in developing countries like India is a major problem for telecom industries because of the unavailability of reliable power supply. The grid supply is not regular in these countries and up to some extent, they are dependent on diesel generators for power supply. But these diesel generators have some major issues such as high operating cost due to high cost of fuel, transportation cost of fuel, high maintenance cost, and these diesel generators also emits pollution to the environment. In presented work, an approach has been proposed for telecom companies for providing power supply to their telecom towers. An economic cost analysis has been proposed by considering various criteria such as cost, air & noise pollution and reliability, etc. Some power supply alternatives including unconventional and hybrid of conventional and unconventional alternatives have been compared to find the solution such as diesel-powered telecom towers, solar powered telecom towers, and their hybrids. The main objective of this work is to provide a reliable, cost effective and environment friendly Remote Area Power Supply (RAPS) system for a particular site in India (Uttar Pradesh). A number of criteria are involved in discussed problem in order to select an effective power supply source. Therefore, the problem has been considered as a Multi Criteria Decision Making (MCDM) problem. To select the best alternative, a Fuzzy AHP and TOPSIS based approach has been proposed. Fuzzy AHP (Analytic Hierarchy process) has been used for calculating the weightage of criteria and the concept of Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) has been applied for ranking the alternatives. The results give assured reliability and sustainability for remote areas using a solar photovoltaic (PV)-diesel generator hybrid energy system.

Complex mathematical modelling of mechatronic modules of promising mobile objects

The characteristics of power sources affect the performance of autonomous electrically driven systems, such as unmanned aerial vehicles, aircraft missiles, guided bombs, torpedoes, space and aerospace vehicles, controlled gliding parachutes. The creation of control systems for the aircraft flight control surfaces of autonomous mobile objects is an urgent topic in modern research. This article provides how a mathematical model based on integrated approach is developed for an energy-efficient mechatronic module for control systems of promising mobile objects powered by various current sources; a comparison of the energy and dynamic characteristics of mechatronic modules of promising mobile objects for various power options is made. As a result, a new type of integrated power-supply source based on capacitive energy storage with floating charge from a primary chemical source of current has been developed. The proposed approaches, dependencies and algorithms can be used in the design of highly efficient mechatronic control algorithms for autonomous mobile objects of a new generation.

AN INNOVATIVE WAY TO CREATE SECONDARY POWER SOURCES WITH HIGH ENERGY PERFORMANCE

The article suggests an innovative way of creating a secondary power supply source-parametric stabilizer on the basis of magnetic semiconductor and electro-ferro-magnetic circuits with practically ideal current stabilization. In contrast to the existing methods of creating parametric stabilizers, the proposed method uses a combination of magnetic semiconductor converter and ferro-resonance-stabilizing device. This combination allows you to create a controlled parametric current stabilizer, characterized by high stability, speed and reliability in operation. Also, as a result of the analysis of the parametric current stabilizer, new analytical expressions have been obtained, allowing revealing simple and accurate methods of calculation of such devices.

Development of a mathematical model of an autonomous power supply source with a free piston motor on the basis of a synchronous electric returning machine with a permanent magnets

One of the current trends at present is the development of small energy, which is a particularly urgent task for the Russian Federation with its vast territories and the specifics of the electric power system. In the Russian Federation, the bulk of the electricity is generated at large power plants and transmitted through power lines. 60–70% of the country's territory lacks a centralized power supply, where more than 20 million people live, and the development of small and micro-energy facilities is necessary. Using a synchronous electric reciprocating machine with permanent magnets in power plants of a modular type makes it possible to rationally design an autonomous power supply source, to obtain the most optimal design. The development of methodological design decisions and the optimization of engine design parameters as part of generating and drive complexes is an important scientific task. A mathematical description of thermodynamic processes in a free-piston internal combustion engine, electromechanical and thermal processes occurring in a synchronous electric reciprocating machine with permanent magnets is developed, which is a necessary condition for designing and optimizing the design of an autonomous electric power complex. According to theoretical calculations, in the Matlab application, on the basis of the additional Simulink module, a simulation model of a free-piston internal combustion engine, linear current load calculation units, stator magnetic induction, magnetic induction created by permanent inductor magnets, electromagnetic force were developed and calculated. The created procedure for calculating the parameters of the electromagnetic component of the force of a synchronous machine with permanent magnets allows you to calculate and optimize the design parameters of the inductor and stator element of the electric motor under consideration. Thus, this will allow us to design electric machines with improved energy characteristics, due to the use of the obtained simulation results, which will allow us to use them more efficiently in the composition of generating and drive complexes.

Automatic System of Synchronous Connection of Backup Power Supply Source in Power Systems with Motor Load

We developed an automatic system of synchronous connection of a backup power supply source in power systems with synchronous and asynchronous motors in case of power loss from the main source. Here, we propose performing continuous monitoring of the instantaneous voltage values of the main and backup power sources and determining the angle between them. The time to send the command to turn the backup power switch on is determined on the basis of the results of approximating the dependence of the angle between the voltages of the main and backup power sources on time. The proposed algorithm can be used in microprocessor fast-acting automatic transfer switch devices to ensure acceptable levels of currents of stators and electromagnetic moments of electric motors in self-starting modes and to maintain a complex continuous technolo­gical process at industrial enterprises. The effectiveness of the developed automatic system of synchronous connection of a backup power supply source has been confirmed using mathematical modeling methods and laboratory tests at an experimental stand.

Justification of the Parameters of a DC/DC Converter for an Autonomous Power Supply Source

As the Smart Grid concept has become a part of the electric power industry development, DC/DC conver­ters have turned into a matter of increased interest. This is due to their effective coordination in the DC-bus system operating different types of power sources, including renewable ones and energy storage devices (batteries, supercapacitor modules), and various loads. The article analyzes switch mode power supply DC/DC converters for autonomous power supply systems. The application of the SEPIC (Single Ended Primary Inductance Converter) type converter is substantiated. The techniques of determining the parameters of the converter are presented. The active phase at the duty cycle operation has been demonstrated, and justified in accordance with the theoretical behavior in response to an input voltage change above and below the desired output value. A simulation of the converter's operation in the buck and boost modes in order to stabilize the output voltage at a set level has been performed in the MATLAB / Simulink package. The obtained simulation results show the effectiveness of the suggested solution for an autonomous power supply source.