Transmission Of Electrical Energy Research Articles

Experimental Study on the Influence of Cross-Section Type of Marine Cable Conductors on the Bending Performance

Through the development of marine energy, marine cables are the key equipment for transmission of electrical energy between surface platforms and underwater facilities. Fatigue failure is a critical failure mode of marine cables. The bending performance of the cable conductor has a major influence on both bending and fatigue performances of the overall cable structure. To study the influence of different types of the conductor cross-section on the bending performances of marine cable conductors, three types of copper conductors with the same cross-sectional area, i.e., noncompressed round, compressed round, and shaped wire conductors, were selected. The experimental results demonstrated that the cross-section type significantly affects the bending performances of copper conductors. In particular, the bending stiffness of the shaped wire conductor is the highest among the three conductor types. Four key evaluation parameters, i.e., the bending stiffness, maximum bending moment, envelope area, and engineering critical slip point, were selected to compare and analyze the bending hysteresis curves of the three copper conductors. The differences in the key evaluation parameters were analyzed based on the structural dimensional parameters, processing methods, and classical bending stiffness theoretical models of the three copper conductor types. The results provide an important theoretical guidance for the structural design and engineering applications of marine cable conductors.

A positive, negative and zero sequences electric power, to improve upon the standard IEEE 1459-2010

PurposesThe purpose of this paper is to identify on the instantaneous electrical power basis of a nonsinusoidal periodic current three-phase asymmetric system, active and reactive positive, negative and zero sequence powers, taking into account higher harmonics. The main power theories, including those embodied in the IEEE 1459 standard, do not allow to evaluate some of power components.Design/methodology/approachA well-known fact is that the three-phase AC system total power with the symmetry of currents and voltages is constant. It corresponds to the electrical energy transfer process in a DC system. In this case, the electrical energy transmission can be taken as high quality. It has been established that the components of active and reactive powers are because of the product of current and voltage of unidirectional sequences. The orthogonal components of the oscillating power are because of the product of the voltage and current components of different sequences, with the exception of the zero sequence.FindingsFor an unbalanced nonsinusoidal mode of a three-phase system, the components of instantaneous power were defined, corresponding to the active and reactive positive and negative and zero sequences powers with the selection of the fundamental and higher harmonics. The active and reactive powers of sequences were divided into two categories – consumed and generated.Originality/valueIt is proposed to use the ratio of “interfere” power RMS value to the total power RMS value to assess the instantaneous power distortion.

Перспективы применения и отработка технологии беспроводной передачи электрической энергии между космическими аппаратами

The purpose of the study was to examine the state and possible fields of short-and-long term application of technology for spacecraft-to-spacecraft wireless transmission of electrical energy. The paper focuses on a space experiment on the transmission of electrical energy from the Russian Segment of the International Space Station to the Progress transport cargo ship in the laser channel and introduces an experiment scheme that provides the required duration of sessions, a given distance of energy transmission, as well as the fulfillment of the safety requirements for the station crew. The paper describes the scientific equipment “Pelican”, developed for the space experiment, specifies its features, gives its main characteristics and layout of blocks, and shows the ways to improve the equipment’s performance to ensure wireless transmission of energy in space.

Solving Electric Transmission Line Wave Equations via Double Gupta Transform

The term electric transmission line adds up to a set of wires belonging to upright electrical conductors furnished with outstanding electric insulation, and operated for transmission of electric energy. Normally, the popular wave equations of electric transmission lines are looked over by the Fourier integral transform, Laplace transform, and techniques of variation of parameter. These techniques are very convenient for looking up differential equations. The Gupta transform is a fresh integral transform that has been put in to look up initial value problems that appear in distinct areas of science and engineering. This paper hands out with solving the wave equations on an electric transmission line with inconsequential leakages through electric insulation to ground via Double Gupta transform. The Double Gupta transform will pan out to be a very fruitful mathematical device put in to look up the popular electric transmission line wave equations.

Wireless Charging of an Electric Vehicle using Solar and Wind

Day by day new technologies are making our life simpler also WPT (Wireless Power Transmission) has been attracting a wide range of subjects in various fields and also becoming a highly active research area because of their potential in providing high technology to our daily lives. WPT will be mandatory to use in the near future because these technologies enables the transmission of electrical energy from a power source to an electrical load across an air gap without interconnecting wires. As the Non-renewable resources on our planet are drastically decreasing even as we speak, our future will be completely dependent on the Renewable resources such as Wind, Solar, Tidal energies, etc. Here we make use of hybrid power generation which is wind and solar power generation for generating DC power. So we worked on a project by combining these two concepts, Hybrid Power Generation and Wireless Power Transmission. Hence the title for the project is “Wireless Charging of an electrical vehicle using solar and wind”. In this paper, we expose and discuss the importance of application of recharge systems to an electrical vehicle. In addition to its vital role in supplying vehicle with the required power recharge system has many type the most important of then is wireless charge system that transmits power from transmitter to receiver without any contact. It is obvious that this power is variable in relation to the speed and has a main function which is loading the battery. In this work our main objective is to focus on the change of state of charge (SOC).ext.

Yağlı tip Transformatörlerde Hibrit bir Soğutma Sistem Tasarımının FEM ve CFD Analizleri

Oil-type transformers (YTT) are electrical machines with high usage in the transmission and distribution process of electrical energy. These transformers are widely used due to their low production costs and wide usage area. In the distribution system of electrical energy, approximately 80-85% of transformers consist of YTT. When these data are taken into account, the importance of the operation, performance parameters and the cooling systems that affect them come to the fore increasingly. The cooling of YTT is generally provided with naphtanic / paraffinic based oils, also called transformer oil. The use of oils for cooling purposes in YTT causes environmental pollution and requires high costs for operation, maintenance-repair activities. Today, current and interdisciplinary researches are carried out for the cooling of transformers with alternative methods.
 In this study, heat transfer of 5kVA YTT at nominal operating conditions in cooling systems designed as hybrids is analyzed by finite element method (FEM) and computational fluid dynamics (CFD). From the results obtained from the designs, the YTT life cycle can be increased up to 5.48 - 166.6 hours.

A goal-oriented approach for supporting input/output determination in regulatory benchmarking

Benchmarking, in many cases by means of Data Envelopment Analysis, is one of the main strategies of regulatory agencies to control the costs of monopolistic companies. In such cases, the determination of inputs and outputs as performance criteria is often an issue. Against this background, we propose a goal-oriented approach that allows to make the so-called Generalized Data Envelopment Analysis (GDEA) fruitful for regulatory benchmarking. As example, we apply this approach to the Brazilian electric energy transmission system operators. As policy implications, we provide directions and discussions on how to apply GDEA in regulatory benchmarking.

Anti-offset performance optimization of coupling coils in wireless power transfer system based on genetic algorithm

With the popularity of electric vehicles (EVs), the application of wireless power transfer (WPT) in EVs has attracted more and more attention. The coupling coil is the key component to realize the stable transmission of electric energy, but in the process of wireless charging, the position of the primary and secondary coils may be misaligned, resulting in the change of mutual inductance and the instability of output current and power. Therefore, the study of the structure of the coupling coil is helpful to improve the transmission performance of WPT. In order to improve the anti-offset ability of the coupling coil, a DS (Double tangent semicircle) coil model based on the DD (Double D) coil is proposed in this paper, which can improve the pick-up ability and anti-offset ability of the receiver coil. Through theoretical analysis, genetic algorithm (GA) optimization, simulation analysis and experiments, it is verified that DS coil is better than DD coil in horizontal offset state and rotary offset state. At the same time, the experiments show when the rotation angle is in the range of −45° to 45° and 135° to 225°, that the current at the receiving end remains stable, and the maximum change rate is only 0.3%. This paper is of great significance to the optimal design of WPT coupling coil.

Accounting the factor of randomity of social processes in prediction of demand for electric energy

Purpose. Taking into account the factor of randomness of social processes when forecasting the demand for electric energy to reduce the error. Methodology. Apparatus of mathematical statistics, linear programming methods, fuzzy set theory and expert assessment methods, scale theory, Bayesian approach to forecasting models, computer modeling. Findings. The dynamics of consumption of electric energy for different periods of time is analyzed, the influence of the pandemic factor on the process of formation of demand for electric energy is established. A verbal-numerical scale has been developed for a comprehensive assessment of the impact on the demand for electric energy of such a complex social phenomenon as a pandemic. A model for forecasting the demand for electrical energy was formed using the Bayesian approach and an experts assessment, which made it possible to use retrospective data on electrical energy consumption and take into account the uncertainty of the social factor influencing the pandemic. Originality. The model for forecasting the demand for electrical energy has been further developed, which, unlike others, takes into account the factor of randomness of social processes and a verbal-numerical scale, which makes it possible to reduce the error in predicting the consumption of electrical energy. Practical value. The research results are useful for enterprises specializing in the generation, transmission and distribution of electrical energy to consumers. The presented results make it possible to reduce the error in forecasting the demand for electric energy, taking into account the factor of randomness of social processes.

Using structured laser illumination planar imaging (SLIPI) as a new technique to monitor the degradation of biodegradable oils in electrical power transformers

The aging process of the insulating oils of an electrical transformer is initiated as soon as the transformer is put into service. The quality of these oils must therefore be rigorously evaluated to have reliable and exploitable data for decision-making. In general, the decision is to continue monitoring, reclaiming/regenerating, or replacing the oil in extreme cases. Thus, early diagnosis of power transformer oils helps prevent potential breakdowns that could considerably impact the electrical energy transmission and distribution network. This research used an imaging technique called SLIPI (Structured Laser Illumination Planar Imaging) to accurately determine the extinction coefficient in different samples of optically dense biodegradable oils (natural and synthetic esters). The variation in the extinction coefficient as a function of the aging of these biodegradable oils under test has been investigated. The results indicate that the SLIPI is reliable as a diagnostic tool for biodegradable oils in power transformers. This technique could therefore be an alternative solution to the conventional monitoring methods.

Analysis of the Effect of Air Gaps on the Electric Field in the Insulation Material of High Voltage Transmission Cables

High voltage (HV) cables are widely used in the transmission and distribution of electrical energy. The design and manufacture of these cables with great precision are of great importance for power systems. Mistakes made during the manufacturing phase and defects that may occur in the structure of the cable material can cause premature aging and continuous malfunctions in the cables. Factors such as air gaps, foreign substances, and moisture in the insulating material may cause punctures and insulation problems in high voltage cables. In this study, the effects of air gaps left as manufacturing defects on the electric field distribution in the insulation of high voltage cables used in power systems were investigated. The effects of 154 kV high voltage cable, the air gap in different coordinates, and diameters in the insulating layer on the electric field distribution in the cable have been investigated. For this analysis, the Finite Element Method (FEM) and ANSYS@Workbench program which realizes a solution based on this method were used. It has been found that the diameter and location of the air gap significantly affect the electric field distribution of the high voltage cable.

Pure Alloy Additive or Preliminary Alloy: A Comparative Study on Obtaining High-Strength Copper Magnesium Alloys Designed for Electrical Power Systems

Due to the increasing demand for electrical energy in modern society, there is a huge requirement for conducting materials and, due to the development of electromobility, this demand is forecasted to grow each year. This is one of the reasons why copper and copper alloys manufacturing and processing industries tend to evolve and improve. One of the improvement paths is the design of new conducting materials for electrical power systems, electrical energy transmission, and energy storage systems. This paper presents a comparative study on obtaining high-strength copper magnesium alloys in terms of the alloy additive used during the metallurgical synthesis process, because this is a crucial, initial element in obtaining the final conducting product, such as wires. The obtained ingots were tested in terms of their chemical composition, and mechanical and physical properties. The provided results prove that there is a significant increase in the materials’ hardness (and thus the ultimate tensile strength), and a slight decrease in density, impact resistance, and electrical conductivity, as the Mg content increases. Scanning electron microscopy (SEM) and phase analysis were additionally conducted in order to determine the distribution and origin of Mg precipitations. Collectively, the results show that the CuMg alloys may successfully replace other alloys, such as CuNiSi or CuZn, as carrying and conducting materials because their properties are superior to those of the aforementioned materials.

Effects of Communication Signal Delay on the Power Grid: A Review

Communication plays a huge role in the operation of modern power systems. It permits a real-time monitoring coordination and control of the transmission, generation and distribution of electrical energy. As the modern grid grows towards an increased reliance on communication systems for the protection, metering and monitoring for as well as data acquisition for planning; there is a need to understand the challenge in the powers’ system communication and their impact on the uninterrupted supply of electrical energy. Communication delays are one of the challenges that might affect the performance of the power system and lead to power losses and equipment damage, it is important to investigate the causes and the mitigation options available. Thus, this paper the state of arts on the cause, the effect and mitigation of communication delays in the power system. Furthermore, in this paper an analysis of different causes of the delays for different network configurations and communication systems used; a comparative analysis of different latency mitigation methods and system performance simulations of a given compensation algorithm is tested against the existing methods. The pros and cons of these control strategies are illustrated in this paper. The summary and assessment of those methods of control in this review offer scholars and utilities valuable direction-finding to design superior communication energy control systems in the future.

Comprehensive evaluation method of transmission line operating status based on improved combination weighting evaluation model

The transmission line is an important channel for the electric energy transmission in the power system. Whether the stable transmission of electric energy is related to key issues such as people’s livelihood and industry, so it is of great significance to evaluate the operation status of the transmission line. Aiming at the shortcomings of the current evaluation methods for the operation status of transmission lines, this paper proposes a comprehensive evaluation method for the operation status of transmission lines based on the improved combination weighting evaluation model. By constructing a transmission line status indication system based on transmission line standards and specifications, comprehensively considering subjective weights and objective weights, the operational health status of the 6 transmission lines in actual operation is calculated, and the calculation results are compared with the evaluation results of the national grid industry standards. In contrast, this method fully combines the advantages of the improved AHP method and the CRITIC method. While retaining the subjective opinions of experts, it can well avoid the phenomenon of unbalanced weights. Compared with the traditional standard evaluation method, it is more in line with objective reality. The evaluation and early warning of the operation status of transmission lines are of great guiding significance.

Systematization and monitoring of quality parameters of overhead power transmission lines functioning

On the basis of quality control methods, the analysis of the causes of technological disturbances (accidents) on overhead power lines was carried out. In particular, the Ishikawa diagram, the Pareto diagram were developed, which made it possible to systematize the main causes of technological violations. The necessity of monitoring the indicators of the reliability of the functioning of overhead power transmission lines by means of information-measuring systems has been substantiated. The structure of an information-measuring system for monitoring parameters that have a negative impact on the functioning quality of overhead power transmission lines is proposed. The proposed system is aimed at ensuring the reliability of the electrical networks operation and improving the quality indicators of services provided to consumers for the transmission of electrical energy.

Step response of Rectifier DC Current Controller and Inverter DC Current-Voltage-Extinction Angle Controllers in a Current Source Converter Based HVDC Transmission Link Connected to a Strong Inverter Side AC system

Abstract: Transmission of electrical energy with High Voltage Direct Current (HVDC) has provided the electric power industry with a dominant means to transmit huge quantity of electricity over very long distances. To investigate the performance, a welldeveloped current source converter based HVDC transmission system model is projected, in which the AC system represented as damped LLR equivalent and is equipped with double tuned harmonic filter to mitigate the AC-DC harmonics and the DC system is secured with rectifier current control, inverter current control, voltage control and inverter extinction angle control. The MATLAB/Simulink based simulation results validate the step response of HVDC transmission system with various controllers. Keywords: HVDC transmission systems, double tuned filter, Rectifier DC Current Control, Inverter DC Current-Voltage - Extinction Angle Control, Step response.

СТАН ТА ТЕНДЕНЦІЇ РОЗВИТКУ СИСТЕМИ ЕНЕРГОЗАБЕЗПЕЧЕННЯ В УКРАЇНІ

The article discusses contemporary issues of ensuring energy security in Ukraine. A brief overview on the modern energy system which comprises power plants of different types, electrical and thermal networks operating in the manufacturing sector, in transmission and distribution of electrical and thermal energy. The study considers the following types of power plants in the energy system of Ukraine: nuclear, thermal, hydroelectric and hydropower stations as well as power plants working with alternative (renewable) energy sources. It is argued that the ratio of energy sources and the energy system balance is the core basis to provide the national energy security and maintain stable power supply subject to different external environment factors. The findings have revealed the dominance of coal and natural gas production in the overall energy balance of Ukraine. However, the study of import and export trends demonstrates the prevalence of energy imports, in particular coal, oil and gas. It is observed that currently, alternative energy sources are at the infant development stage. The study of alternative energy supply in Ukraine shows that over 2018–2020 the capacity of such power plants increased by 7%, in particular, the capacity of wind stations grew by 2.3 times and solar – by 4.3 times, thus exhibiting respective change in energy output. It is also observed that during the period under consideration, the renewable energy output dropped by 17.1% while wind power production increased by 2.8 times and solar – by 5.2 times, respectively. According to the results, over 2018–2020 the capacity of wind power plants increased from 0.9% to 2.0% of the total domestic output, and solar – from 2.3% to 9.4%; as to production, the share of energy generated by wind power increased from 0.8% to 2.4%, and solar – from 0.7% to 4.1%. Given the current trend of increasing energy output generated from alternative sources, there is reason to tap a growing interest in the activities of companies offering power generating equipment in the Ukrainian market. A study on the capacity needs has revealed that the most popular among consumers of autonomous power supply systems, about 70% of total sales refer to low and medium power generators in the range of 8–550 kW. The conclusions resume that the key driver in boosting the alternative energy supply system is the relevant legal framework that encourages further alternative energy supply market development and, accordingly, the market of power generating equipment in Ukraine characterized by a strong upward growth trend.

FINDING PERCENTAGE OF BREAKDOWN STIMULATION OF ALUMINUM WIRES THAT OPERATES IN A CORROSIVE MEDIUM

The study of the duration of mechanical resistance to static tensile stress (withstand time) for an aluminum wire that being suffers from the corrosion effect stimulated by stray currents at different temperatures. Test device was designed and produced locally "in advance" in accordance with the specification (ASTM G103 - 97) to create static tensile stress of (1 N) on an aluminum wire of type ASTM (B231/B231M) with particular dimensions and utilized in the transmission of electrical energy, and when the wire is surrounded by a corrosive environment (NaCl solution) (3.5 % NaCl) at three different temperatures (25, 50, and 75 ° C) without any external electrical current causing corrosion; this symbolizes stray currents. Then compare the findings of that example to the results of the same wire's withstand time in the presence of an external electrical current generated by corrosion of type (D.C) by (5V & 3A).Following that, the resulting diagrams were analyzed, and it was discovered that the wire resistivity time (without the existence of stray currents and at a temperature of 25 ° C) completed (17 days), which is the longest duration of endure, and the lowest time of resistivity or resistance period (in the existence of an external electric current) is (18 hr.).Impact of (stray currents) at (75 ° C), and this is an indicator of the stray currents with corrosive environment temperatures on the resistance period (withstand duration) in the existence of static stress. The total stimulation increase is 1.9% between corrosion at 75°C and 25°C.

Transition of energy system by regulating of Power Quality for efficiency improvements

The supply of electrical energy is of importance for the value creation of most industrialized nations. Ultimately, electrical energy is able to provide the appropriate useful energy at the point of need with virtually no emissions. This aspect plays a greater role today than ever before. When using electrical energy as a clean and sustainable energy source, it is important to note that there can be significant losses in the transmission of electrical energy between the point of generation and the point of use. These transmission losses are caused, among other reasons, by line losses due to power quality deviating from the ideal value. In principle, any deviation from the nominal values of the supply voltage listed in EN 50160 (such as voltage level, frequency or harmonic distortion) leads to an increase in transmission losses. Thus, compliance with the power quality parameters is desirable from all perspectives of (economic, ecological, social) sustainability. Especially with reference to SDGs 7, 8 and 12, a supply voltage that complies with the specified parameters is important. Unfortunately, no incentives currently exist for minimizing deviations in power quality parameters and the transmission losses they cause. Goal should be to implement a transition of energy system that provides incentives to increase the transmission efficiency of electricity. One possibility for this is the unbundling of the guarantee of the power quality parameters on a separate market. Regulatory framework conditions must be adapted for sustainable improvements in energy transmission at all levels. Nevertheless, the economic viability of power quality based business models is difficult. A promising solution is to reintroduce a supplementary factor as an extension of the equation of the incentive based regulation. The vision of the business model explained in the paper is to contribute to the efficient operation of the power grid by avoiding the propagation of harmonics through the use of compensation equipment, this is a new approach that has not yet been investigated.

Termodinamička analiza reflektovanog solarnog zračenja na nagnutim PV modulima u južnoj Indiji

A substantial volume of energy is necessary for meeting the rising energy demand as a result of the rapid growth of population, and lifestyle changes of the society. Tilted PV module improves operation and reduces the risks involved in the generation, transmission, and utilization of electrical energy and thermal energy without any degradation in climatic conditions (like conventional sources of energy). Both fixed and tilted PV module systems receive high incoming solar radiation. In this study, the analysis of output current and voltage for varying tilt angles from 00 to 300 for different southern parts of India (Chennai, Bengaluru, Thiruvananthapuram, and Hyderabad) has been performed. The reflected albedo factor is considered for different locations ranging from 0.07 to 0.75 with the current-voltage performance parameters. Variations in PV module inclination angle with variations in the total solar radiation under different ground albedo values have been observed. The current and voltage changes with tilt angle at different locations have been studied. The monthly variations and temperature effects on exergy efficiency and solar radiation were analyzed.