Reliability of distributed energy facilities

2021 ◽  
Vol 14 (1) ◽  
pp. 45-51
Author(s):  
F. Byk ◽  
L. Myshkina

The reason for the appearance of the first distributed generation in Russia was the high requirements to the reliability of power supply to power consumers of a special group of the first category of reliability. Diesel generating units were used to ensure uninterrupted operation. High costs for technological connection of consumers of the 1st and 2nd categories of reliability have strengthened the tendency to install a backup energy source in the enterprises' own power supply systems. However, setting reserves leads to a decrease in economic efficiency. There are additional costs for maintaining the reserve in a working condition. As a result, enterprises transfer the backup units to the mode of the main power source, and that of the backup function to the centralized power supply system. The creation of such industrial MiniGrid operating in a mode without power supply to the grid increases the cost of electricity for other consumers. Besides, with the departure of industrial enterprises from the centralized power supply, the share of communal and non-industrial consumers is growing. This requires an increase in the manoeuvrability of energy sources. The creation of balanced Energy Cells for energy supply to the population and small and medium-sized businesses that provide services to the population is not accompanied by the negative effects indicated above. In Russia, there are isolated examples of such systems, similarly operating in a mode without supplying power to the grid. Changes are needed to allow active consumers to supply excess capacity to the grid during peak hours in the UES of Russia, for which the grid companies need to be allowed to operate at least in a mode without supplying power to the grid, which will not lead to a decrease in grid companies' revenues from electricity transmission services. The introduction of these changes does not only lead not only to an increase in the reliability of power supply but also to an increase in the economic efficiency of the UES, which will reduce the price of electricity.

2020 ◽  
Vol 178 ◽  
pp. 01077
Author(s):  
A.N. Alyunov ◽  
A.Yu Belyanin ◽  
A.E. Nemirovsky ◽  
D.A. Zaripova

This article considers an urgent task of using autonomous sources for power supply systems of industrial enterprises of small and medium-sized production. The efficiency of choosing the time of their switching-on in peak hours of power system in order to reduce the cost of electricity is shown on the example of diesel generators.


Author(s):  
Yaroslav Bederak ◽  
Viktor Taradai ◽  
Hanna Kyselova ◽  
Vladlen Kyselov

The publication presents the most common and promising models and schemes for replacing the power supply system of industrial enterprises, and an example of their use in practice for power supply to sewage treatment plants of a chemical enterprise. Various types of models are considered (in tabular form, in the form of an electrical replacement circuit or in the form of a finite-state machine), as well as a logical-probabilistic approach to the representation of the power supply system. The use of automation systems in power supply systems of industrial enterprises can reduce the total number of accidents, prevent their development, reduce the time of disconnections of electrical installations and downtime of mechanisms, and also allows to transfer to work without constant maintenance a significant number of electrical installations of substations, which, in turn, leads to a reduction in the number of service personnel, increase labor productivity and reduce maintenance costs. One of the main tasks on the way to automating the power supply system of enterprises is to present it in the form of a model. The list of replacement models and schemes that can be used to represent the power supply system of enterprises is quite large, and choosing the appropriate model, for that best meets the requirements of the final goal is quite a complex scientific task. The purpose of this article is to analyze the most common and promising models and schemes for replacing the power supply system and provide recommendations on their application in practice for power supply to sewage treatment plants of a chemical enterprise. Presenting the power supply system in the form of a table allows you to simplify and visually perform certification of electrical equipment, identify problem and weak points in the power supply system of industrial enterprises. Such a table proves that a large amount of electrical equipment at lower levels depends on a single electrical device at higher levels. The representation of the power supply system in the form of a three-phase symmetric replacement circuit can be used to calculate short-circuit currents in symmetric and unbalanced modes in the MatLab program and similar. Using the model of the power supply system in the form of a finite-state machine allows you to visually check the reliability of power supply to consumers, simplify the design of the power supply system of an industrial enterprise, select the state of switching devices in the power supply system and take into account the advantages and disadvantages of each state. It is advisable to use the methods discussed in this article to represent the power supply system (in tabular form, in the form of a finite-state machine or a three-phase symmetric replacement scheme) and their further application and use in automated power supply systems of industrial enterprises. The logical-probabilistic method allows us to consider the issue of power supply reliability based on the theory of logical algebra.


2020 ◽  
Vol 37 (3) ◽  
pp. 76-82
Author(s):  
L.V. Mazitova ◽  

The article presents the results of studying various measures to promote the natural renewal of lime forests in the Kasmarsky uchastkovoye forestry of the Zianchurinsky forestry. The data on lime forests within the boundaries of the forestry were studied, and the calculation of the economic efficiency of promoting natural regeneration was carried out. The use of evenly-gradual and continuous narrow-cut logging in the conditions of the Zianchurinsky forest area in the Kasmar district forest area will avoid the creation of expensive forest crops. The cost of creating forest crops is 10,719. 4 rubles per 1 ha, and the cost of preserving and caring for the forest during evenly-gradual logging is 4,237. 9 rubles, and solid narrow-cutting-3,469. 33 rubles.


Author(s):  
E. I. Gracheva ◽  
A. N. Gorlov ◽  
Z. M. Shakurova

The article examines the main features of the layout of electrical equipment for shop networks of internal power supply with the definition of indicators for a group of shop customers connected to a single power center, affecting the choice of the structure of schemes for shop network sites. The parameters characterizing the circuit topology are revealed. A study is presented of the influence of the load factor of workshop transformers on their reactive power factor, it is proved by calculation by technical and economic criteria the feasibility of replacing a workshop transformer with two with a lower total power. The calculation of energy savings in the in-plant power supply systems. The type of dependences tgφ of transformers ТМ and ТСЗ with various rated powers in the function of loading transformers is established. The most significant factors of the growth of idle power losses during operation are presented. With determination of losses of active and reactive power and electricity in transformers and losses of active power in a high voltage distribution network A feasibility study was carried out on the options for internal power supply schemes with two transformers of lower power installed instead of one, and the feasibility of such a replacement to increase the efficiency of the equipment was proved and the estimated payback period for the investment capital was determined. A comparative analysis of the studied power supply schemes of industrial enterprises with the identification of their advantages and disadvantages.


2013 ◽  
Vol 50 (3) ◽  
pp. 12-23 ◽  
Author(s):  
N. Levin ◽  
E. Kamolins ◽  
V. Pugachev

Substantial improvement of the undercar inductor generator used for supplying power to passenger cars is achievable through increasing its specific power, reliability, reparability, and decreasing the cost of its manufacturing. It is proposed to integrate electrically the armature and excitation windings of the generator thus considerably simplifying its design while reducing its mass and consumption of non-ferrous metals. To gain these advantages a test prototypal generator was made and bench-tested. The results of tests show that a 1.5-fold mass reduction is achievable along with good technical-economic indices of the generator.


Author(s):  
T. Babynets ◽  
◽  
Y. Tyutyunnik

The purpose of the work - to conduct a study of economic efficiency developed in L. Pogorilyy UkrNDIPVT design solutions for family dairy and fattening farms of cattle and sheep farms of different sizes, adapted to EU requirements. Research methods. During the analytical research, an economic evaluation of the effectiveness of the developed design solutions of dairy and fattening farms of cattle, as well as sheep farms of different sizes was made. Investments in the creation of livestock facilities were determined by the following components: construction of farms, acquisition of machinery and technological equipment, the cost of purchasing livestock. The estimate for the construction and technical equipment of the farms included the costs of construction materials, machinery, equipment, construction and installation work. The calculated method was determined by the cost of funds per animal place and the output of gross output, taking into account the planned productivity. The need for land for the operation of farms was calculated according to the needs of animals in feed for the production of planned livestock products. Calculations of profitability of production and payback period for the creation of livestock facilities were carried out according to generally accepted methods of determining economic efficiency. Research results. According to the results of research on the economic efficiency of projects of livestock facilities, developed in L. Pogorilyy UkrNDIPVT and adapted to EU requirements, the following expected indicators were obtained. To create dairy farms for 10, 15 and 25 cows with young livestock, respectively: the need for total investments is 1535.89 thousand UAH, 2038.78 and 2964.20 thousand UAH; expenditures per animal - UAH 76 thousand, UAH 68 thousand and UAH 59 thousand; the need for land for the operation of farms - 16 hectares, 24 and 40 hectares; the level of profitability of farms, provided that the planned productivity is reached, will be 60, 64 and 61%; payback period -5.2; 4.4 and 4.0 years, respectively. In order to create family farms for fattening young cattle, respectively, by 25, 50, 100 heads: the need for total investment is 489.3 thousand UAH, 764.1 and 1253.0 thousand UAH; expenditures per animal - UAH 19.5 thousand, UAH 15.3 and 19.5 thousand; the need for land for the operation of farms - 10, 20 and 40 hectares; level of profitability - 40%; the payback period for the creation of such farms is 5, 4.5 and 4 years, respectively. To create family sheep farms for 25, 50, 100 heads of fattening and 100 heads of dairy sheep farms, respectively: the need for total investments is UAH 252.20 thousand, UAH 357.81 thousand, UAH 568.39 and 76.47 thousand; expenditures per animal - UAH 10.20 thousand, UAH 7.10 thousand, UAH 5.60 and 10.20 thousand; the need for land for the operation of farms - 3.1, 6.2, 12.3 and 13.8 hectares; level of profitability - 25%; payback period for the creation of farms - 5, 4,5, 4 and 4 years. Conclusions. Studies of the economic efficiency of livestock projects developed in L. Pogorily UkrNDIPVT and adapted to EU requirements, namely different sizes of family dairy and fattening farms of cattle and sheep farms testified to the high economic feasibility of their creation and use. Key words: sheep breeding, economic efficiency, capital investments, estimate, level of profitability, cattle breeding, livestock farms, payback period.


Author(s):  
Arkadiusz Adamczyk

This article presents an analysis of energy demand by a group of portable military use appliances. This analysis was used by the author to offer an solution aimed at reducing the weight of the power supply system. This solution is based on energy profiles which were derived from the analyses and measurements, and on applying appropriately modified hybrid supply sources. Catalogue data are often used in support of an analysis of performance of electronic appliances. For a user, documents prepared by a manufacturer are the main source of information concerned with the amount and quality of electric energy sources required for the appliance to work properly. Investigations carried out in real conditions often verify this data, which provides a base for seeking alternative solutions in the course of designing new sources of power, e.g. such as the ones proposed in the article.


Author(s):  
G. M. Gospodarenko ◽  
◽  
O. D. Cherno ◽  
A. T. Martynyuk

The issues of recoupment of nitrogen fertilizers are considered, since they determine the need for fertilizers and the agro-economic efficiency of their use. It is shown that the payback of fertilizers is a complex value and not constant in different crops. The increase in yield from fertilizers in kind is taken on the basis of field experiments with fertilizers carried out on podzolized chernozem of the opita field of the Uman NUS. The cost of an increase in the yield from the use of nitrogen fertilizers was determined by the average actual sales prices of products prevailing on the market through various sales channels in the 6th quarter of 2021. Additional costs included: the cost of fertilizers, a margin for their delivery to the farm, the cost of using it on the farm and collecting increase in yield from nitrogen fertilizers. The cost of ammonium nitrate was taken at UAH 24,000 / t with the addition of a margin for their delivery to the farm. The costs of using fertilizers on the farm and collecting an increase in yield were set calculated according to the accepted standards. The difference between the value of the yield increase (PU) and additional costs (AD) gives the net income received from the use of fertilizers. The ratio of the cost of increasing the yield to additional costs shows their payback. On the basis of comparing the indicators of PU and DZ, the boundaries of the economic efficiency of the use of fertilizers were determined: PU> DZ (general expression of the task). We also calculated the minimum required increase in yield from fertilizers and the limits of price increases for nitrogen fertilizers. It has been established that at a price of ammonium nitrate of UAH 24,000 / t and the cost of its use in optimal doses for field crops against the background of a balanced phosphorus-potassium nutrition, the cost of an increase in yield is 3075–47894 UAH/ha. Payback of 1 kg a.c. nitrogen fertilization varies in a wide range – from 3.0 to 217.3 hryvnyas, depending on the crop. The limit of the unprofitable price per unit of the active substance of nitrogen fertilizers at the optimal application rate depends on the crop and is in the range of UAH 76.5–219.0 /ha. With the current disparity in prices for crop products and ammonium nitrate (24,000 UAH/t), its use is profitable, which is explained by the low ability of podzolized chernozem to provide plants with nitrogen, biological requirements of crops for this food element and technologies for their cultivation. Key words: nitrogen fertilizers, agricultural crops, fertilizer recoupment, loss threshold, price increase limit.


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