scholarly journals Influence of low-voltage electrical switching and protecting devices and parameters of electrical equipment on electricity losses in workshop power supply networks

2021 ◽  
Vol 23 (3) ◽  
pp. 3-13
Author(s):  
E. Yu. Abdullazyanov ◽  
E. I. Gracheva ◽  
A. N. Gorlov ◽  
Z. M. Shakurova ◽  
A. G. Logacheva
Keyword(s):  
Power Supply ◽  
Low Voltage ◽  
Electrical Equipment ◽  
Load Factor ◽  
Equivalent Resistance ◽  
Circuit Breakers ◽  
Supply Networks ◽  
Factors Affecting ◽  
Daily Schedule ◽  
Active Power Losses

THE PURPOSE. To develop an algorithm for estimating electricity losses, taking into account the influencing factors in the main circuits of shop power supply. To study the influence of the main parameters of electrical equipment on the equivalent resistance of the distribution busbar. METHODS. We use element-by-element methods for calculating active power losses using equivalent resistance on the example of a section of the main circuit of the shop network. Factors affecting the equivalent busbar resistance, such as the root-mean-square load factor, the load graph shape factor, the resistance of the contact connections of switching devices, and the ambient temperature, are investigated. RESULTS. The values of the resistances of the branch lines from the busbar are calculated taking into account the heating of the conductors and the resistances of the circuit breakers and magnetic starters installed on the line during the element-by-element calculation. The relations in the value of the equivalent resistance of the busbar to the values of the resistances of the contact connections of low-voltage electrical devices installed on the branch lines from the busbar, the values of the resistances of the branch lines taking into account heating, the value of the resistance of the busbar and the values of the resistance due to the heating of the busbar are revealed. CONCLUSIONS. The share of each of the studied parameters in the value of the equivalent resistance of the busbar is determined. The value of the relative error in determining the equivalent resistance of the busbar depending on the number of connected electric receivers and taking into account the studied parameters is calculated. The estimation of the value of the electricity losses of the section of the main scheme of the shop network was carried out in accordance with the daily schedule of the load of consumers.

scholarly journals COMPARATIVE ANALYSIS OF METHODS OF CALCULATION AND ERRORS OF ACTIVE POWER LOSSES IN LOW VOLTAGE COMMERCIAL NETWORKS

2019 ◽  
Vol 20 (9-10) ◽  
pp. 13-24
Author(s):  
E. I. Gracheva ◽  
R. R. Sadykov ◽  
R. R. Khusnutdinov
Keyword(s):  
Cross Sections ◽  
Low Voltage ◽  
Active Power ◽  
Load Factor ◽  
Equivalent Resistance ◽  
Power Losses ◽  
Line Load ◽  
Industrial Networks ◽  
Commercial Networks ◽  
Active Power Losses

The article analyzes some methods for calculating the loss of active power in lowvoltage industrial networks, taking into account the main influencing parameters. Equivalent resistance and losses of active power in radial and trunk circuits are determined. The errors of the equivalent resistance and the loss of the active power of the circuits relative to the reference values are calculated. Graphic dependencies of the equivalent resistance of the radial and trunk circuits of the industrial networks are taken into account, taking into account switching devices on the lines in the functions of such parameters as the total cross-section of lines, average lengths, cross-sections of lines and ambient temperature, and with a change in the line load factor. The proposed nomograms are highly accurate and can be used in practical calculations.

scholarly journals Calculation of the economy of electric energy in industrial electrical supply systems

2020 ◽  
Vol 22 (2) ◽  
pp. 65-74
Author(s):  
E. I. Gracheva ◽  
A. N. Gorlov ◽  
Z. M. Shakurova
Keyword(s):  
Power Supply ◽  
Energy Savings ◽  
Reactive Power ◽  
Electric Energy ◽  
Electrical Equipment ◽  
Total Power ◽  
Load Factor ◽  
Advantages And Disadvantages ◽  
Industrial Enterprises ◽  
Supply Systems

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.

scholarly journals Algorithms and models of power losses in circuit breakers installed in networks

Vestnik MGTU ◽  
2020 ◽  
Vol 23 (4) ◽  
pp. 345-353
Author(s):  
E. I. Gracheva ◽  
A. N. Gorlov ◽  
A. N. Alimova
Keyword(s):  
Power Supply ◽  
Low Voltage ◽  
Technical Condition ◽  
Active Power ◽  
Operating Conditions ◽  
Public Utility ◽  
Electrical Networks ◽  
Power Losses ◽  
Circuit Breakers ◽  
Technical Parameters

Determination of the main characteristics of the topology and technical condition of equipment underoperating conditions is necessary for analyzing and assessing power and electricity losses in intrashoplow-voltage industrial power supply networks. A comparative analysis of the technical characteristicsof automatic circuit breakers VA57-31 (KEAZ), NSX100 TM-D (Schneider Electric), DPX3 160 (Legrand), Tmax XT1 TMD (ABB) has shown that the main technical parameters of the machines are close in their values. At that it has been found out that automatic switches of the BA57-31 series have the lowest value of power losses per pole (7.5 W), whereas the automatic switches of the Tmax XT1 TMD series have the highest value (10 W). Thus, under the operating conditions of the equipment, the lowest value of power and electricity losses is characteristic of low-voltage electrical networks with installed circuit breakers of the BA57-31 series, and the highest value of losses is noted in in-shop systems with installed circuit breakers Tmax XT1 TMD. Using catalog data, the dependences of active power losses in circuit breakers on rated currents have been established; the algorithms have been developed and the obtained dependences have been modeled using approximating functions. The standard deviation of the compiled approximating functions has been calculated. Analytical expressions of the dynamics of power losses per pole have been determined as a function of the rated current. The graphical dependences of the investigated parameters of low-voltage equipment have been presented. The developed models are recommended to be used to increase the reliability of the assessment and refinement of the amount of active power and electricity losses in low-voltage electrical networks of industrial power supply systems, agrotechnical complexes, and enterprises of the public utility sector.

scholarly journals ELECTRIC SUPPLY OF UNDERGROUND CONSUMERS OF DEEP ENERGY-INTENSIVE MINES

2018 ◽  
pp. 25-46
Author(s):  
F. P. Shkrabets
Keyword(s):  
Power Supply ◽  
Supply Voltage ◽  
Maximum Load ◽  
Electrical Equipment ◽  
Transport Systems ◽  
Local Power ◽  
Electrical Networks ◽  
Electric Networks ◽  
Supply Networks ◽  
Technical And Economic Indicators

The increase in the capacity of cleaning and construction vehicles for highcapacity and energy-intensive mines calls for an increase in the  supply voltage of cleaning and tunneling combines, as well as  transport systems: from a voltage of 660 V switched to 1140 V, and  now to 3300 V. This allows improving technical and economic  indicators for clearing and access areas, as well as improving the reliability of local Power Supply Systems (PSS). However, this  trend prevents the supply of underground electric networks with a  voltage of 6 kV, in connection with which the problem arises of  increasing the voltage of supply networks. To date, it has become  possible to apply the 10 kV voltage to the operation, which is most  acceptable for the use of electrical equipment for electrical networks  and protection devices. Leading educational, research and design  organizations were engaged in research on this issue. An analysis of the results of the research showed that switching to 10 kV voltage is  justified and timely. At the same time, 35 kV voltage is not removed  from the agenda, which is technically feasible and economically  justified, but there are problems with the safety of its operation in  underground workings, which requires appropriate refinement. This  level of voltage will improve the quality of electricity.Conclusions: 1. Application of 35 kV voltage in the underground power supply system of coal and ore mines is advisable at a depth of more than 1000 m with a maximum load of at least 1000 kVA at the  level of the stem cables.2. Application of 35 kV voltage in underground electrical networks will allow to significantly improve the quality indicators of voltage,  reliability, and economy of the system due to the current unloading  of the most important element of SES, such as stem cables.3. Analysis of the main parameters and characteristics of electrical mine electrical equipment gives reason to believe that it allows  implementing a trend of 35 kV deep input to deep horizons of mines  (mines) and placement of 35/6 kV substations on working horizons.

scholarly journals Analysis of the Degradation of MOSFETs in Switching Mode Power Supply by Characterizing Source Oscillator Signals

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Xueyan Zheng ◽  
Lifeng Wu ◽  
Yong Guan ◽  
Xiaojuan Li
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Nuclear Power ◽  
Low Voltage ◽  
Junction Temperature ◽  
Factors Affecting ◽  
Die Attach ◽  
Switching Mode Power Supply ◽  
Switching Mode ◽  
State Resistance

Switching Mode Power Supply (SMPS) has been widely applied in aeronautics, nuclear power, high-speed railways, and other areas related to national strategy and security. The degradation of MOSFET occupies a dominant position in the key factors affecting the reliability of SMPS. MOSFETs are used as low-voltage switches to regulate the DC voltage in SMPS. The studies have shown that die-attach degradation leads to an increase in on-state resistance due to its dependence on junction temperature. On-state resistance is the key indicator of the health of MOSFETs. In this paper, an online real-time method is presented for predicting the degradation of MOSFETs. First, the relationship between an oscillator signal of source and on-state resistance is introduced. Because oscillator signals change when they age, a feature is proposed to capture these changes and use them as indicators of the state of health of MOSFETs. A platform for testing characterizations is then established to monitor oscillator signals of source. Changes in oscillator signal measurement were observed with aged on-state resistance as a result of die-attach degradation. The experimental results demonstrate that the method is efficient. This study will enable a method to predict the failure of MOSFETs to be developed.

scholarly journals Manufacture of High Current Low Voltage Power Supply with Using the Mot (Microwave Oven Transformer)

2020 ◽  
pp. 301-306
Author(s):  
Arman Hidayat Sirait ◽  
Kerista Tarigan ◽  
Marhaposan Situmorang
Keyword(s):  
Power Supply ◽  
Low Voltage ◽  
Electrical Equipment ◽  
Microwave Oven ◽  
High Current ◽  
New Methods ◽  
Iron Smelting ◽  
Parallel Circuit ◽  
Secondary Winding

The manufacture of low voltage high current power supply using the MOT (Microwave Oven transformer) has been done. The purpose of this work is to convert low voltages into high currents by utilizing simple electrical equipment. This work use of varying voltages and different windings which are changed on the secondary winding section with a cable size of 240 mm 2, NYA cable type. The test is carried out with a series circuit, parallel circuit, and single circuit by utilizing a voltage of 30 V, 60 V, 90 V, 120 V and 5 different variations of winding. The results of this test provide knowledge of new methods that can be applied to iron smelting.

3D Thermal Analysis of a Power Supply Busbar Structure

2010 ◽  
Author(s):  
Adrian Plesca ◽  
Alina Scintee
Keyword(s):  
Thermal Analysis ◽  
Power Supply ◽  
Low Voltage ◽  
Circuit Breaker ◽  
Convective Heat Exchange ◽  
Point Of View ◽  
Circuit Breakers ◽  
Transient Thermal ◽  
Supply Systems ◽  
Electrical Apparatus

Busbar technology is more and more used to realize connections within power supply systems in answer to the need of compactness. The integrated problem on heat conduction and radiation-convective heat exchange describes the temperature regime in current conductors and current carrying busbars of power electrical apparatus such as circuit breakers or high breaking capacity fuses. Beside steady-state conditions, the transient thermal regime of busbar has an important influence upon whole power supply system from thermal behaviour point of view. Hence, a 3D thermal analysis of a power system including fuse, low voltage circuit breaker and busbars connections, using a specific software package based on Finite Element Method, has been done. From 3D thermal modelling and simulations, the thermal transient impedance for the busbar has been computed. This allows a better correlation between protection characteristics of the fuse and circuit breaker and busbar design.

Short-Circuit Current Criterion under Condition of Protection Action in Low Voltage Power Supply System

2013 ◽  
Vol 860-863 ◽  
pp. 1914-1918
Author(s):  
Yi Rong Su ◽  
Jie Yu ◽  
Jun Liu ◽  
Gan Zhou ◽  
Li Ping Zhan ◽  
...  
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Low Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Supply System ◽  
Circuit Breakers ◽  
Level Of Automation ◽  
Current Criterion ◽  
The Impact

In order to improve the level of automation and security of the low voltage power supply system, this paper proposed the calculation method of short-circuit current criterion under condition of protection action. Firstly, the impact of circuit breakers on the short-circuit current is analyzed. Then, the current criterion under condition of short-circuit protection are given. Finally, using a special case, the calculation process of aforementioned current criterion is given in detail.

scholarly journals Research and Application of Transformer-User Identification Technology Based On Fault Diagnosis of Electrical Information Acquisition Equipment

2019 ◽  
Vol 136 ◽  
pp. 04054
Author(s):  
Muxin Zhang ◽  
Liyan Kang ◽  
Bing Cao ◽  
Ying Shang ◽  
Qiutong Wu ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Power Supply ◽  
Information Acquisition ◽  
Loss Rate ◽  
Low Voltage ◽  
Factors Affecting ◽  
Professional Management ◽  
Marketing Professional ◽  
Power Line Carrier ◽  
Line Loss

The line loss rate of power supply enterprises is an important economic and technical index, which directly reflects the lean level of marketing professional management of power supply enterprises. At present, the confusion of transformer-user archives in transformer area is still widespread, which is a key issue in line loss management in power supply enterprises. As the downlink communication channel, low-voltage power line carrier can realize cross-station reading, which brings great difficulties to the identification of transformer-user relation. Because the data of calculating the line loss rate of the transformer area depends on the electrical information acquisition system, the running state of the electrical information acquisition equipment is also one of the important factors affecting the line loss rate of the transformer area. This paper will focus on the fault diagnosis technology of electrical information acquisition equipment, and use it to carry out the identification of transformer-user transformers.

scholarly journals Specificity of energetic functioning of economic activity objects

2018 ◽  
Vol 44 ◽  
pp. 00010 ◽  
Author(s):  
Karol Bednarek ◽  
Artur Bugala ◽  
Dorota Typanska ◽  
Leszek Kasprzyk
Keyword(s):  
Energy Management ◽  
Power Supply ◽  
Power Supply System ◽  
Negative Impact ◽  
Electrical Equipment ◽  
Supply System ◽  
Higher Harmonics ◽  
Supply Networks ◽  
Electromagnetic Disturbances

Ecology is strongly related to the quality of energy management and to limiting the negative impact of the technosphere on the environment. This work refers to the analysis of energy quality and power balances in different, due to the specificity of functioning (used electrical equipment), business facilities. The research was carried out for supply networks: in the bank building, in the IT laboratory and in the office and warehouse facility. The measurements of currents, voltages, active, reactive and apparent power in individual phases of power supply system as well as distortions (higher harmonics) of currents and voltages were carried out. The research was carried out to identify irregularities in the networks and to indicate ways to limit the effects of electromagnetic disturbances (mainly higher harmonics) as well as achieve improvements in energy efficiency and ecology in the operation of these facilities.

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