scholarly journals THE EFFECTIVENESS OF VALIDATION MEASUREMENTS IN AUTOMATED SYSTEMS OF THE POWER SUPPLY SYSTEMS CONTROL IN ACCORDANCE WITH LIMIT VALUES

2017 ◽  
Vol 60 (5) ◽  
pp. 407-416 ◽  
Author(s):  
V. A. Anishchenko ◽  
T. V. Pisaruk
Keyword(s):  
Power Supply ◽  
Operational Reliability ◽  
Probability Of Detection ◽  
Measured Variable ◽  
Operating Personnel ◽  
Limit Values ◽  
Technological Processes ◽  
Wide Range ◽  
High Level ◽  
Supply Systems

A high level of operational reliability of power supply systems is virtually impossible to provide without operational control of the reliability of the measurement variables (currents, voltages, powers, energies, temperatures, pressures) that characterize the condition of power equipment and technological processes. Reforming the power engineering and its transition to market relations necessitate one to toughen the requirements for the reliability of the measuring information. Inaccurate measurements are a potential source of misdiagnosis of malfunctions of equipment and they cause incorrect operation of emergency control equipment and erroneous actions of operating personnel in the control of technological processes. Operational methods of reliability control that enhance the operational reliability of the measuring information are based on the usage of the semantic value of the measured data, their consistency, process consistency, and consistency of balance. These methods use technological sense of the measured variables and they complement the methods of hardware status monitoring of automated control systems based on digital codes. That improves the overall operational reliability of the transmission, collection and processing of information. The most common semantic method of control is the method of limits (“fork”) that compares the numeric value of the measured variable with the upper and lower boundaries of valid values. The disadvantage of limit values in many cases is its poor resolution, due to the wide range of appearance of results of measurements. This reduces the probability of detection of gross and systematic errors of measurements more than it may be accepted. With this regard, the objective of a reasonable narrowing of the range of valid values of the variables, that uses the theory of statistical decisions, acquires high relevance.

scholarly journals The method for increasing the efficiency of equipment’s maintenance in railway traction power supply systems

2018 ◽  
Vol 47 (3) ◽  
pp. 39-47 ◽  
Author(s):  
Oleksandr Matusevych ◽  
Valeriy Kuznetsov ◽  
Viktor SYCHENKO
Keyword(s):  
Power Supply ◽  
Operational Reliability ◽  
Technical Condition ◽  
Repair System ◽  
Maintenance And Repair ◽  
Traction Substations ◽  
Electric Equipment ◽  
Traction Power Supply ◽  
Supply Systems ◽  
Traction Power

Purpose. To develop the method for increasing the efficiency of the equipment’s maintenance and repair system, ensuring necessary level of operational reliability of the equipment, safety and reliability of the electric equipment with minimal expenses on operation. Relevance. Aging of the power equipment in railway power supply systems sharply raised a need for assessment of its states and degree of risk for operation outside rated service life. In critical conditions of technological processes and operational modes of the railways it is necessary to increase the equipment’s operational reliability. The scheduled maintenance and repair system whose main technical and economic criterion is the minimum of equipment’s downtimes on the basis of a rigid regulation of repair cycles, in the conditions of market regulations in the field of repair in many cases does not provide the optimal decisions due to insufficient financing. The solution of this problem is possible by improvement of the maintenance and repair system. Under these conditions the main direction for supporting the operational reliability of power electric equipment on TS is a development of the modern methods based on individual supervision over real changes of technical condition of power equipment. Scientific novelty. In this article the authors proposed an integrated approach, on the basis of which can be developed the effective maintenance and repair system for traction power supply systems. Proposed approach allowed to react quickly to changes of service conditions on traction substations, to control the technical condition of power electric equipment under the conditions of uncertainty, to establish interrelation between quality of service and operational reliability of the equipment, to choose a service strategy on traction substations. Practical importance. The validity of the developed method was confirmed by the results of calculations and practically by choosing the optimal maintenance's option for transformer TDTN-25000/150-70 U1 (ТДТН-25000/150-70 У1) on traction power supply substation.

scholarly journals Increasing the contact line operational reliability by forecasting its constructive elements’ failures

2021 ◽  
Vol 2131 (3) ◽  
pp. 032006
Author(s):  
P A Bodrov ◽  
N A Popova ◽  
A L Ganashek
Keyword(s):  
Contact Line ◽  
Power Supply ◽  
Operational Reliability ◽  
Software Tools ◽  
Mathematical Tool ◽  
Forecasting Method ◽  
Supply Systems

Abstract The article discusses the issues of calculating the indicators of the power supply systems’ reliability. The analysis of the existing problem and options for its solution are given. To assess the patterns, the authors proposed a mathematical tool. The method based on the rectangular scores’ technique is adopted as a forecasting method. The development belongs to the class of specialized method-oriented software tools.

Combined Way of Diagnostics of Reinforced Concrete Conical Structures

2018 ◽  
Vol 931 ◽  
pp. 346-351 ◽  
Author(s):  
Elena Yu. Romanenko ◽  
Mikhail A. Trubitsin
Keyword(s):  
Reinforced Concrete ◽  
Power Supply ◽  
Power Transmission ◽  
Operational Reliability ◽  
Power Transmission Line ◽  
Reinforced Concrete Structures ◽  
Repair Work ◽  
Conical Section ◽  
Supply Systems ◽  
Conical Structures

Reinforced concrete conical structures are the basis of safety and operational reliability of railways power supply systems. The article presents optimal methods for diagnostics of reinforced concrete structures, which allow recommending the sequence and amount of repair work aimed at restoring or maintaining the required state of reinforced concrete conical section structures (contact-line supports, power transmission line supports, etc.). A design scheme is proposed for determining the residual bearing capacity of the support in the presence of cracks and corrosion of the reinforcement.

scholarly journals Designing an uninterruptible power supply based on the high efficiency push–pull converter

2013 ◽  
Vol 16 (3) ◽  
pp. 29-40
Author(s):  
Phuong Minh Le ◽  
Dzung Quoc Phan ◽  
Huy Minh Nguyen ◽  
Phong Hoai Nguyen
Keyword(s):  
Power Supply ◽  
High Efficiency ◽  
Harmonic Distortion ◽  
Original System ◽  
Uninterruptible Power Supply ◽  
Switching Power ◽  
Wide Range ◽  
Uninterruptible Power ◽  
Modulation Control ◽  
High Level

This paper presents an implementation of the DC/DC push–pull converter for an uninterruptible power supply (UPS). Some classical DC/DC converters are presented and analyzed for pointing out their advantages and drawbacks. Besides, an original system based on a push-pull converter associated with a dynamic modulation control is chosen. The main advantage is the possibility to control the delivered electric power in a wide range from very low level to high level of voltage within the same basic architecture. It can reduce the switching power losses and increase the power conversion efficiency. This paper proposed a new control scheme of the DC/DC converter and DC/AC inverter. The suggested system consists of a high efficiency DC/DC converter and a singlephase DC/AC inverter has been simulated using Matlab/Simulink and designed basing on the DSP TMS320F28027. Both results show high performances of the DC link and AC load voltages, when load changes from zero to rated. The performance of the proposed system has been verified through a 1kW prototype of the system for a 50 Hz/220-230 VAC load sourcing by two series connected batteries of 12V. The proposed DC/DC converter achieves a high efficiency of 93.0%. The system including the DC/DC converter and DC/AC inverter achieves an efficiency of 91.2% and Total Harmonic Distortion (THD) of AC load voltage reached 1.9%.

scholarly journals Battery Charger with Bidirectional Power Transmission

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Andrii V. Harnytskyi ◽  
Evgenii Volodymyrovych Verbytskii
Keyword(s):  
Electric Vehicles ◽  
Power Supply ◽  
Output Voltage ◽  
Power Transmission ◽  
Renewable Energy Sources ◽  
High Energy ◽  
Pause Duration ◽  
Soft Switching ◽  
Wide Range ◽  
Supply Systems

The gradual reduction in price of electric batteries contributes to their wider use in autonomous and centralized power supply systems as a backup source of electricity and increase the share of electric vehicles. In the paper the conditions for increasing the efficiency of electric vehicle batteries, in particular in the framework of the concept of V2G (Vehicle to Grid) as a drive for the organization of autonomous power supply systems are analyzed. It is shown that this is possible only with the simple integration of batteries into the system, flexibility, and a wide range of modes that have to be provided by unified charge-discharge devices. Such charging devices have to have such features: a wide range of input and output voltage parameters; correction of the input power factor; the ability to take the maximum power from renewable energy sources; high energy efficiency. A review of possible topologies for a charger with bidirectional power transmission and a bridge converter with soft switching of transistors at zero voltage, which has a high efficiency, galvanic isolation and the ability to correct the shape of the current. The modes of operation of the converter are analyzed and conditions of soft switching is obtained. It is shown that soft switching is valid for current that is not less than minimal one. Efficiency of the converter with soft commutation is compared with a similar converter with rigid commutation of transistors. It is shown that static losses in converter with soft commutation it higher than in the rigid one. So, the proposed converter should be used if the increase in static losses is compensated by the lack of dynamic losses. Additional feature of the converter is that the regulation of the output voltage of the converter with soft switching is carried out according to the law of frequency-pulse modulation with a constant pause duration, where the pause duration is determined by the period of resonant processes of the converter. The model of the converter in Matlab Simulink is built and it is shown that the efficiency of the proposed converter topology is 10-15% higher, which together with the possibility of sinusoidal current with THD ≈ 20% and two-way transmission energy indicates the feasibility of its use as a charger for electric vehicles under the concept of V2G. However, it should be noted that the use of LCL filter creates a phase shift between voltage and current and degrades the THD value. To improve the shape, it is possible to use specialized laws of modulation [or to use modular converters, which allow to obtain a continuous current shape and reduce the volume of the filter.

scholarly journals Method of selecting parameters of cable lines distributive networks 10 kv in uncertainty conditions

2019 ◽  
Vol 139 ◽  
pp. 01082 ◽  
Author(s):  
A.D. Taslimov ◽  
A.S. Berdishev ◽  
M.V. Melikuziev ◽  
F.M. Rakhimov
Keyword(s):  
Electric Power ◽  
Power Supply ◽  
Optimal Number ◽  
Electric Load ◽  
Electric Power Supply ◽  
Wide Range ◽  
Urban Distribution ◽  
Cable Lines ◽  
Supply Systems

The article discusses the task of selecting the optimal number of types and values of standard cable sections of urban distribution electric power supply systems under conditions of uncertainty of electric load development using zoning method and proves the expediency of using a very limited number of standard cable sections (application of one or two standard cable sections at wide range of load DNsity variation).

scholarly journals Systems mutual loadings of traction asynchronous cars

2019 ◽  
Vol 294 ◽  
pp. 05009
Author(s):  
Andriy Afanasov ◽  
Oleksandr Shapovalov ◽  
Maryna Voitenko
Keyword(s):  
Power Supply ◽  
Power Efficiency ◽  
Reactive Power ◽  
Capital Expenditure ◽  
Wide Frequency Range ◽  
Electrical Machines ◽  
Rolling Stock ◽  
Frequency Range ◽  
Wide Range ◽  
High Level

The review of methods of post-repair tests of traction asynchronous motors under conditions of locomotive depot is carried out.The necessity of introducing special stands for post-repair tests is shown in order to improve their quality, reduce the number of failures of service equipment, improve safety of the railway transport. Let’s consider a question of power supply of the research asynchronous engine in wide frequency range and also a possibility of creation of the universal stand for testing important asynchronous engines of the electrorolling stock. Survey of possible versions of the scheme mutual loadings of asynchronous electrical machines which can be used for testing traction asynchronous engines of the rolling stock is executed. Such systems can be constructed both with use of the static converter of frequency, and without it. The given short characteristic of each alternative, certain advantages and shortcomings of each of system options. It is shown that systems with use of static converters of frequency differ in high power efficiency, allow to carry out tests in the wide frequency range of power supply, however have higher prime cost. Schemes without converters of frequency differ in smaller power efficiency, impossibility to carry out tests in the wide range of frequency of power supply, high level of consumption of reactive power . The results of the carried-out analysis can be used when choosing rational option of a system mutual loadings of asynchronous electric motors which will differ in higher functionality and power efficiency. Use of such systems will allow to lower capital expenditure for creation new and modernization of traction electrical machines that exist at the station for test.

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