Application of the Similarity Criteria for Estimation of Electromagnetic Compatibility of Frequency Electro Drives with Power Supply System of Industrial Enterprises

AC steel arc furnaces are the most powerful units connected to the electrical grid, the operating mode of which is dynamic, asymmetrical and non-linear. That is why these furnaces cause the entire possible range of negative effects on the quality of electricity in the grid, in particular, fluctuations, asymmetry and non-sinusoidal voltage.Known proposals for improving the electromagnetic compatibility of electric arc furnaces are mainly focused on eliminating the consequences of their negative impact on the power grid.The proposed approach and the corresponding technical solution are aimed at reducing the level of generation of a negative factor and at the same time reduce fluctuations, asymmetry and non-sinusoidal voltage. This result is obtained due to the fact that the proposed solution takes into account the peculiarities of the range of modes natural for arc furnaces. Optimal for such consumers is the use of a constant current power supply system I=const in the range of modes from operational short circuit to maximum load and the system U=const in the whole other range of modes. The implementation of such a system is carried out on the basis of a resonant converter «constant current – constant voltage».Studies have found that the use of such a power supply system, in comparison with the traditional circuit, makes it possible to reduce the non-sinusoidal voltage in a low-power grid from 3.2 % to 2.1 % and the unbalance coefficient from 3.66 to 1.35 %. Previously published data on a significant reduction in voltage fluctuations was also confirmed.The positive effect of such a system on the energy performance of the furnace itself is shown, manifested in an increase in the arc power by 12.5 %, and the electrical efficiency by 5.1 %. This improves the productivity and efficiency of electric arc furnaces

Download Full-text

DEVELOPMENT OF AN ALGORITHM FOR CREATING A THREE-DIMENSIONAL GRAPH OF THE TOTAL HARMONIC OF VOLTAGE COMPONENTS RATIO

Vestnik Chuvashskogo universiteta ◽

10.47026/1810-1909-2021-1-56-67 ◽

2021 ◽

pp. 56-67

Author(s):

Nadezhda M. Drey ◽

Ayrat G. Ziganshin ◽

Georgi M. Mikheev

Keyword(s):

Power Supply ◽

Power Supply System ◽

Reactive Power ◽

Short Circuit ◽

Three Dimensional ◽

Supply System ◽

Electrical Network ◽

Industrial Enterprises ◽

Harmonic Components ◽

Dimensional Graph

In the power supply system of industrial enterprises with low installed capacity, a battery of cosine capacitors is used as reactive power compensation devices in most cases. However, in certain modes of operation in such a network due to the presence of electrical receivers, which generate the highest harmonics, there may be resonance phenomena. Therefore, in such a network you should know both the presence of harmonic components and their percentage. It is known that according to GOST 32144-2013 it is necessary to take into account not only the individual harmonic components of the voltage of about 40 harmonics, but also the total ratio of these components. For this reason, the calculation of this parameter in the power supply system of consumers is an urgent task. In this paper the principle of structure of the three-dimensional graph of the total factor of harmonic components of voltage is revealed. The arguments for the dependence of this factor on the most important parameters of the electrical network, such as system short-circuit power, capacitor bank, load consumption are given. The authors have developed an algorithm for creating a three-dimensional graph of the total harmonic voltage components coefficient with the disclosure of the principles of its construction. As an example, the paper presents graphical dependencies: kU = f(SКZ , QBK ); kU = f(SКZ , PNG ); kU = f(QBK , PNG).

Download Full-text

PROSPECTS AND BACKGROUND INTRODUCTION OF AUTONOMOUS POWER SUPPLY SYSTEMS FOR AGRICULTURAL ENTERPRISES

ENGINEERING, ENERGY, TRANSPORT AIC ◽

10.37128/2520-6168-2020-3-5 ◽

2020 ◽

pp. 51-63

Author(s):

Ihor Kupchuk ◽

Vitalii Yaropud ◽

Nataliia Telekalo ◽

Valerii Hraniak

Keyword(s):

Power Supply ◽

Alternative Energy ◽

Power Supply System ◽

Agricultural Sector ◽

Lithium Ion ◽

Supply System ◽

Industrial Complex ◽

Combined System ◽

Agricultural Enterprises ◽

Industrial Enterprises

The agro-industrial complex is one of the most stable in terms of revenue to the budget of intersectoral formations, in which significant amounts of electricity produced using fossil fuels, mainly imported, fuel resources are consumed for the implementation of production processes, which poses a threat to its effective functioning and makes in the research article. The purpose of the article is to assess the potential and determine promising methods of decentralized power supply for agro-industrial producers based on the analysis of modern technical and technological solutions in the field of electrical engineering and the synthesis of a promising scheme for a combined autonomous power supply system for agricultural enterprises. The article assessed the technical and technological capabilities for the use of autonomous electrical installations by small and medium-sized enterprises of the agricultural sector, operating on the principle of conversion of renewable sources, taking into account the natural and climatic potential of the Vinnytsia region. As a result of a comparative analysis of the operational characteristics of the known methods of accumulating electric energy, it was found that in the conditions of autonomous power supply of small and medium-sized agro-industrial enterprises due to the conversion of alternative energy sources, the most functionally and economically justified option is the use of energy storage systems based on flywheels with partial use of a backup unit lithium-ion batteries. Based on domestic and foreign experience, a promising scheme of a combined autonomous power supply system for small and medium agricultural enterprises was proposed and priority areas for further research were formed to improve the efficiency of such a system. The study of technical and technological prerequisites for the development of a combined system of autonomous power supply and its components was carried out using methods of analysis, generalization and a systematic approach. The potential advantages and effect of the proposed scheme implementation are based on the laws of development of technical and electric power systems.

Download Full-text