Scientific Journal of KubSAU

The article shows the main advantages and disadvantages of renewable energy sources. It is shown, that in general, the use of renewable energy in the world has acquired real momentum and stable growth trend. An interesting fact is that the greatest application was currently the most mutable and unstable form of energy - wind. The total global installed capacity of large wind turbines, according to various estimates, is approximately 20 GW. This is because the specific investment in wind power is lower than with most other forms of renewable energy. The article presents features of the design and operation of modern wind power stations. It is shown that when choosing wind power plants and stations we must take into account the following main parameters and factors: the average value of amount of electricity consumed by power consumers on a monthly basis; power generator; uptime in the absence wind or when weak wind. The study shows block-circuit solutions of different options of energy systems made using wind power plants. We have also disclosed prospects of development wind energy and considered the advantages and the features of the choice of the main functional units of wind power stations which will increase the effectiveness of predesign work on the creation of high-performance systems of electrosupply with combined power supply systems based on renewable energy sources

This article discusses the basic analytical expressions for the calculation of power generators and select features basic functional units of wind turbines, allowing the design phase to conduct a preliminary assessment of the effectiveness of wind power stations, which supplies specific consumers of electric power

The article shows that to improve the performance of autonomous systems we need new methods and principles of their design, associated with both the use of renewable sources and the application of new technical solutions of electromechanical generators and static stabilizers and inverters electric power settings. We have disclosed modern requirements for generators of electric power, as well as features of calculating the parameters of contactless electrical power generators: asynchronous generators capacitive excitation and asynchronous generators with permanent magnets. The article presents some analytical expressions for calculating the electrical losses and the efficiency of the generators, specific weight and power. It is shown, that expedient to designing contactless electrical power generators to carry out as part of the autonomous electricity supply systems, as it is sometimes advantageous to understate the main criteria of efficiency of generators, in order to improve, for example, weight and overall dimensions of static converters. The conclusion is made that in order to improve the efficiency of designing contactless electrical power generators in the early stages of designing it is necessary to carry out a preliminary assessment of the main criteria of efficiency of contactless electrical machines. We have also discussed analytical expressions, which might be used for preliminary evaluation of application features for various types of contactless generators in the stand-alone electricity supply systems taking into account the conditions of use

Currently one of the promising areas to significantly improve efficiency of energy saving is the introduction of renewable sources of energy into the energy system. In the field of solar energy, we consider solar photovoltaic power plants with direct conversion of solar radiation into electricity using solar panels as the most promising ones. The article examines the main factors that reveal the prospects of applying solar photovoltaic power plants. It also discusses the main advantages and disadvantages in comparison with traditional and other renewable energy sources. To improve the operational and technical characteristics of solar power plants in their structure significantly, it is proposed to use new components. Stand-alone inverters for single-phase transformers with rotating magnetic field will reduce the number of power electronic devices in the conversion circuit; they will simplify the system of control and protection, reduce electromagnetic interference and improve overall efficiency and reliability of the converter of the solar power plant. In addition, the modular design of solar power plants will also increase the reliability of the power system due to redundancy of the major functional elements. It is also important that the construction of solar power plants in a modular way enhances maintainability of the system, it significantly reduces the time for maintenance and troubleshooting in emergencies; it simplifies the task of changing its structure depending on requirements of users. The article reveals peculiarities of work and the main benefits from the application of solar photovoltaic power plants

The article deals with one of the promising areas belonging to energy-saving technologies; it is the introduction of biogasoline stations into agricultural production. The analysis of the application in the world has been shown. To determine the cost-effectiveness of biogasoline stations we have shown the data for the calculation of the potential of biomass: organic waste settlements; animal waste; waste of poultry; crop residues; waste processing industry. We have obtained graphic dependences of electricity generated in the day from livestock and poultry, as well as the number of sunflower, rice, and sugar beets. The table also shows the thermal properties of organic agricultural wastes, allowing increasing the efficiency of calculations to determine the biomass resources. We have considered the schemes of biogasoline stations, a gas turbine power plant and a steam turbine power plant and disclosed the features of their work. To improve the operating and technical specifications of the stations intended for power generation we have proposed using non-contact generators and stabilization of parameters of electric power in their designs to carry out direct frequency converter. We have disclosed the advantages and disadvantages of biogas, as well as the direction of its effective use. It is shown that the use of all the possibilities in the complex of biogasoline stationns (production of fertilizers and motor oil, production of heat and electricity) would improve the efficiency and the payback of investment would be from 3 to 5 years, which is mainly determined by the volumes of biomass

The article reveals the advantages of low energy in comparison with other renewable energy sources. It is shown that broad prospects are visible for small (100 - 1000 kW) and micro hydropower plants (up to 100 kW) when used in the foothill and mountain areas. At the same time, the construction of hydropower plants of sleeve-type has improved the operational and technical characteristics, among other types of small-scale power plants. The article presents main analytical expressions for calculating hydroelectric power generator and it has built graphic dependences for the power generator of pressure and water flow. To improve the performance of small hydroelectric power plants we have proposed using unregulated water turbine and non-contact induction generator in their construction, thus, we could stabilize voltage and frequency directly by the frequency converter. Depending on the requirements of consumers to power supply reliability and electricity quality, we have offered several options for structural and circuit solutions of autonomous systems of electrosupply, made using small hydroelectric power plants. Thus, we can greatly enhance the efficiency of such systems if they are used with other types of renewable sources, such as windfarms or solar power plants

In the article, there were cited the resources of wind en-ergetic, hydroenergetic, solar energetic and biomass of the Krasnodar region

The article analyzes the main characteristics of the electricity generators to use them as a part of small hydroelectric power plants. It is shown, that contactless asynchronous generators in comparison with synchronous generators and DC generators have improved their operational and technical characteristics, and above all, their reliability and performance efficiency. We have shown graphic dependences of the cost and the weight of power generators. It is proposed using direct frequency converter as a stabilizer of parameters of asynchronous generator of electricity, used as a source of electricity for small hydropower plants. The article explains the features of the work and the choice of parameters for generators, working together with the direct frequency converters. The authors have revealed some aspects of the work of direct frequency converters with natural commutation and with adjustable phase angle, including their advantages and disadvantages. The article also presents block diagrams for small hydroelectric power plants, made with the help of asynchronous generators and direct frequency converters

The article describes the principles of classification, as well as the basic requirements and features of wind power plants projecting

In the article we have considered the technical solutions of voltage regulators and the frequency of current of the asynchronous generators of the wind power installations executed with the help of the direct frequency transformers. The comparative analysis of them has been carried out as well