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Принятие комплекса законодательных актов в сфере энергетики, объединяемых термином Energiewende , существенно изменило структуру потребления энергии в Германии: в настоящее время наи-большую долю в ней занимает зеленая энергия, выработанная за счет использования ветра, солнца, воды и биомассы. Подобные изменения, безусловно, можно расценивать как успех. Однако, одновременно с целена-правленным изменением структуры производства и потребления энергии в Германии возникли определенные социально-политические, экономические и юридические проблемы, требующие тщательного изучения. Дискус-сионным является вопрос о соответствии целей и предлагаемых мер их достижения, в частности, в отношении бесперебойности энергообеспечения, расширения электрических сетей, совершенствования подхода к ценооб-разованию, экологических последствий с учетом курса на тотальное расширение производства энергии за счет возобновляемых источников. Актуальными для Германии и затрагивающими энергетическую политику России являются вопросы ускоренного сворачивания ядерной энергетики и легитимности национального курса Герма-нии на продвижение зеленой энергетики в контексте интеграции с Европейским энергетическим рынком. В статье выполнен анализ указанного комплекса проблем и охарактеризована роль национального законода-тельства Германии в их решении. from wind, solar, water and biomass now provides the largest contribution to the total electricity consumption. In this respect, Energiewende can be regarded as an overall success. But in parallel to this scenario, a critical discourse has evolved concerning socio-political, economic and legal issues. The congruence of objectives and measures for example, in regards to ensuring security of supply, expansion of electricity networks, development of electricity price and envi-ronmental consequences in the course of expansion of electricity generation from renewable sources is the main focus of socio-political and economic discussions. Accelerated phase-out of nuclear energy and constitutional disputes regarding the legality of national orientation of the promotional scheme for green electricity in respect to the integration of German electricity sector in the European internal market for energy are in the centre of the debate and have a remarkable impact on the energy policy in Russia as well. Against this background, present article examines the con-tribution of German Energiewende to the resolution of complex challenges of the developed industrial society. №4 (226) (2017)

The object of research is a static transformer frequency converter, which can be used to combine parallel-operating power systems having different operating frequencies. The aim of the work is to study operational characteristics and evaluate strategies and laws of the proposed device from the point of view of developing methods and means of power transmission improving quality via electrical communication, containing a frequency converter based on phase-shifting transformer made according to zigzag-triangle scheme and controlled by power keys. In order to achieve the above object, it is proposed to sectionalize control windings providing a 48-position with a discreteness of 2.5 °, and a 24-position with a discreteness of 5 ° switching in each 120 ° sector of "coarse" regulation. Structural simulation models were built and computational experiments were carried out for electrical communication combining two power systems with frequencies of 60 and 50 Hz and 50 and 49.6 Hz, respectively. The most significant results are: a new circuit version of the frequency converter, various strategies for controlling the conversion process. The two-channel frequency converter allows to reduce by 2 times the number of "coarse" control keys, which switch not after 60°, but after 120°. Also succeeded to reduce the switching step from 5 degrees to 2.5 degrees, which made it possible to improve the conversion quality. The significance of the obtained results is that during regulation the number of keys connected in series in operation remains equal to 4, which can significantly improve the reliability indicators of the control system.

The work is dedicated to the study of the influence of the wind turbine lightning protection system on the possibility of a lightning strike to the lightning rod, to the protected object and to the surface of the earth. The aim of the work is to study atmospheric electric fields for a complex object: a wind turbine, a thundercloud and a surface of the earth, in two versions - with and without a lightning protection system. This goal is achieved by constructing a mathematical model based on the Laplace equation of elliptic type and boundary conditions for calculating the electric flow function. Computational experiments over a wind turbine carried out in two basic configurations: using a rodtype lightning protection system and without it. The most significant result of the work is a mathematical model with boundary conditions that determines the rigid boundaries of the object of study and constant values at the free and symmetric boundaries for calculating the electric flow function, the method of finding the specific distribution of the lines of the flow function along the boundaries of the studied wind power installation, and the results of computational experiments. As a result, it was found that the applied numerical calculation method allows analyzing the features of the atmospheric electrostatic field near the pointed peaks. The proposed mathematical model makes it possible increasing of the efficiency of lightning protection of a power plant and can be used to simulate other objects using a rod type of lightning protection.

Sustainable economic development is also determined by the availability of primary energy supply. Geographical incoherence of energy production and consumption areas leads to new challenges in providing consumers with energy. The purpose of this work is to analyze and assess trends and problems related to the provision of energy resources, mainly of the natural gas for Republic of Moldova in the context of new challenges in the natural gas market and rhe changes in their transport infrastructure. The investigative methodology is based on the analysis of time series of production, consumption and import of energy resources at global and regional level in 1990-2017. It is proposed to using the linear approximation functions. The coefficients and the its signs of these functions ("plus" or "minus") and the value of and the determination coefficient are used for the quantitative analysis of the production, consumption and import trends of primary energy and natural gas. Europe and Asia ensure their energy balance by massive energy imports. The Southeast European region, including the Republic of Moldova, imports large sums of primary energy resources. The need to import natural gas in the Romania-Moldova-Ukraine sub-zone is currently estimated at about 12 million tons of oil equivalent. The new energy corridors for the transportation of natural gas will lead to new challenges regarding the natural gas supply of the Republic of Moldova. Information on possible scenarios of natural gas supply to the Republic of Molodova is presented and the estimated costs for natural gas transport for these scenarios are presented.

The purpose of the work was to study the basic constructional, energetic and technological features of electrochemical reactors (activators) used in processing of whey – a dairy by-product, but also a biologically very valuable liquid. The choice of optimal regimes for processing of various types of whey is specified, aimed at raising the efficiency of isolation of whey protein fractions in the protein-mineral concentrates while reducing energy intensity. It is also demonstrated that it is necessary to reasonably select such constructional features of electro activators as the distance between the electrodes and between the electrodes and the membrane as well as their geometric shape so as to avoid appearance of “dead” areas and to assure a high efficiency of the process. It was also important to find the most appropriate option of electric parameters and processing regimes (periodic or continuous). Besides, the account was taken of the ratio of the whey volume to the main electrode area; of the membrane type; of the initial content of dry matter in each whey type, i.e., its protein compositions; the concentration and composition of the anodic (secondary) liquid. The results of the investigation are of importance in the development of a wasteless technology of by-products processing.

The work deals with district heating systems based on cogeneration plants and the use of carbon dioxide heat pumps in them. Heat pumps are used in heating systems of buildings and use the heat of outdoor air as a source of low potential heat and, at the same time, the heat of return network water. The aim of the study is to develop the structure of a heat four-pole (HFP) for fitting of heat pumps with district heating system, determine the parameters of a heat exchanger with a variable surface area of the heat exchange installed in the return water line, and analyze one of the schemes of the HFP. The goal to be sought is achieved by solving the following tasks: development of requirements and justification of the HFP scheme, justification of it’s parameters. The most significant results are developed models of statics and dynamics of heat exchanger in HPF, means of the integration of carbon dioxide heat pumps into heat networks with high temperature schedules. The significance of the results obtained consists in deriving dependencies between the temperature schedule of heating system and HFP parameters, which can be used in the practice of designing a district heating systems with heat pumps. As a result of calculations, equations were obtained for the describing of the relationship between the area of the heat exchanger installed in the return water line, temperature drops at the ends of the heat exchanger, heat power of the heat exchanger.