Bus Duct Research Articles

Temperature Analysis of Single busbar With Variation of Total Harmonic Distortion in Current

Typically, busbars are used to transmit and distribute currents in a bus duct system. The alarming use of nonlinear loads in the industrial sector or at residentials, such as arc welding, computers, ballast lighting, variable speed drives, and so on, has resulted in the generation of harmonics in current distortion, which are uncontrolled and thus increase heat generation within the system. The research conducted in this paper focuses on the prediction of the heat distribution as well as the analysis on operating temperature of a single busbar with compliance to the British National and International Standard (BS 159: 2014) using the Finite Element Method (FEM) in COMSOL Multiphysics software. The copper busbar dimension used for this research was 20mm x 6mm x 300mm, and the fundamental Root Mean Square (RMS) current was 419.1 A. The size of this busbars can withstand the maximum current of 430 A at a maximum operating temperature of 90°C, which complies with the standard requirement. The fundamental current is injected with variation of total harmonic distortion in current up to 55% with an interval of 5%. According to the findings, the operating temperature increases in direct proportion to the increase in total harmonic distortion with the current injections. With the presence of 55% of total harmonics in the current, the current was increased up to 57.73 A from the fundamental current, while the operating temperature was increased up to 140C from the fundamental temperature. The total harmonics in current produced by the nonlinear loads could affect the operating temperature of the busbars, and this continuous operation of current flow will affect the busbars' lifespan due to the occurrence of overheating.

Thermal performance optimization for a tapered heat sink of bus bar conductor using definitive screening design

This study examines and optimizes four design parameters of a bus duct conductor's heat sink: fin pitch, fin height, fin thickness, and the number of fin valleys. Average surface temperature and Nusselt number are chosen as the thermal performance criterion of the heat sink. A Definitive Screening Design is employed as a statistical method to reduce the number of optimization runs required while minimizing the aliasing. The regression analysis, analysis of variance, main effect analysis and optimization are conducted to optimize the heat sink design parameter and its thermal performance. The current results provide an ideal heat sink design for the casing of bus duct conductors. A fin pitch of 4 mm, fin height of 6.5 mm, fin thickness of 1 mm, and six fin valleys are determined to be the most optimal combination of design parameters. The optimized responses' average surface temperature and Nusselt numbers are 72.05 °C and 21.59, respectively, with 2.97 % and 6.25 % deviation from the predicted values of the empirical equation. The experimental results are benchmarked against the IEC 60439-1 and IEC 60439-2 standards. The current analysis is expected to provide more insight into the impact of design factors on the thermal performance of a bus duct conductor.

Fire detecting for dense bus ducts based on data fusion

A method based on data fusion is proposed for detection of fire in dense bus ducts in buildings. The environmental temperature data, infrared image data and gas concentration data are used in the fire warning system. The features of temperature data and gas concentration data are extracted by statistical method, the features of infrared image are extracted by Faster RCNN (Region Convolutional Neural Networks), then three types of features are fused and inputted into the SVM (Support Vector Machine) model to detect fire early. The experimental results show that this method has high recognition rate and good robustness.

Численное моделирование испытания на термостойкость закрытого трехфазного шинопровода 10 кВ в режиме трехфазного короткого замыкания

Численное моделирование испытания на термостойкость закрытого трехфазного шинопровода 10 кВ в режиме трехфазного короткого замыкания

Influence of Fin Thickness on the Thermal Performance and Selection of Coating Method for a Bus Duct Conductor

This paper studies the fin thickness variation effect on a bus duct conductor’s thermal performance and the nanocomposite coating method selection for the bus duct conductor’s heat sink. ANSYS FLUENT was used to create a numerical model resembling the experimental setup. The IEC 60439-1 and IEC 60439-2 standards were used to benchmark the experimental data. The results revealed that the “chimney effect” induces an increment of the hot air adjacent to the heat sink. A conspicuous increase in the total heat transfer rate and fin effectiveness was observed as the fin thickness was reduced. This study revealed that s1 = 1 mm was the best fin thickness with 1.254 fin effectiveness, 1.862 W of total heat transfer rate, and 17.5 Nusselt number. Additionally, various coating methods were examined experimentally to select the best nanocomposite coating for the bus duct conductor’s heat sink. The ultrasonic agitation was the best coating method, which resulted in the lowest average resistance (8.8 μΩ) and a better percentage of Ag (0.6%–2.5%) on the substrate surface. Thus, the current outcomes are expected to better comprehend the impact of fin thickness on thermal performance, as well as the selection of coating method for the bus duct conductor.

Разработка тепловой модели токопровода с полимерно-газовой изоляцией для передачи электроэнергии оффшорных ветроустановок

On the basis of the National Research University "MPEI", within the framework of the project to create a busbar with polymer-gas insulation for the transmission of electricity from offshore wind turbines, a study is being carried out to develop insulating structures for high-voltage busbars. The work is devoted to the development and justification of the design of a special conductor with combined insulation (polymer-gas) for laying in sea water for the transmission of electrical energy from wind turbines, where a polymer coating of current-carrying elements is used to increase the electrical strength and reduce the dimensions of the current conductor, and for to reduce electricity losses, the main gas insulation is used. Technical solutions for the execution of linear and connecting sections of bus ducts with polymer-gas insulation are presented. An analysis of the distribution of the thermal field in the coaxial gap was performed, demonstrating the features of design solutions for linear sections.
 According to the calculations, conclusions were drawn about the possibility of using combined insulation in special conductors.

A study on the effect of the number of fin valleys on the thermal performance of a bus duct conductor

This paper presents a finite volume-based simulation study on the effect of the fin valley's number on the thermal performance of a bus duct conductor. A numerical model that closely mimics the experimental setup was developed using ANSYS FLUENT. The experimental data were used as a benchmark and followed the IEC 61439-1/2 standards. Five fin valley numbers were considered: s1 =2, s2 =3, s3 =4, s4 =5 and s5 =6. It was determined that the average surface temperature decreased as the number of fin valleys increased. From the analysis, it was observed that as the number of fin valleys increased, convection heat transfer improved as a consequence of enhanced surface Nusselt number. The best number of fin valleys was s5 =6, exhibiting superior thermal performance over a lower number of fin valleys. This study is expected to provide a better understanding of the fin valley’s effects on the thermal performance of a bus duct conductor’s casing.

A study on the effect of fin pitch variation on the thermal performance of a bus duct conductor

The numerical results of this work provide an optimum design for a three-dimensional natural convection heat sink on the bus duct conductor's casing. The size of the fin pitch is regarded as a design variable. Using ANSYS FLUENT, a numerical model that closely resembles the experimental setup was created. The experimental data were compared to the IEC 60439-1 and IEC 60439-2 standards as a benchmark. Five potential fin pitch sizes (s1 = 1.0 mm, s2 = 1.5 mm, s3 = 2.0 mm, s4 = 3.0 mm, and s5 = 4.0 mm) were taken into consideration. It was shown that as the fin pitch gap size is reduced, the average surface temperature falls. According to the investigation, conduction resistance increased while convective resistance reduced as the fin pitch gap size grew. The overall heat resistance did, however, rise. The optimal fin pitch size, s1 = 1 mm, outperformed the other fin pitches in terms of thermal performance. The current numerical analysis expects an improved knowledge of the influence of fin pitch on a bus duct conductor's thermal performance.

Comparative analysis of trolley busbar parameters of different geometric shapes under the condition of higher current harmonics

Modern workshop power supply systems can have a significant length. Therefore, their parameters and electrical characteristics have a significant impact on power quality, operation modes of electrical consumers and energy efficiency of technological processes. Available in engineering practice methods of calculation of parameters and characteristics of bus ducts are based on methods of circuit modeling. Circuit parameters are usually determined on the basis of generalized equations. These equations are derived from a number of assumptions, which limits the scope of their use. Alternative methods, based on empirical dependencies, can be used to calculate the electrical parameters and characteristics based on field modeling. Thus, the paper proposes a mathematical two-dimensional field model of electromagnetic processes in the frequency statement of the problem, allowing with high accuracy and efficiency of numerical implementation to decompose electromagnetic processes in the active elements of the trolley busduct and for each relevant amplitude and frequency of the k-th harmonic current to determine the electromagnetic parameters. busduct with regard to their design features, nonlinearity of magnetic and electrical properties of materials, the skin effect, the blitz effect. A general analysis of active and inductive resistances of busduct phase trolleys depending on their shape, material and current harmonic spectrum is performed. The level of asymmetry of busbar parameters caused by proximity effects, surface effects, skin effects and other edge effects is given. It is found that in the presence of higher current harmonics, the parameters (active and reactive supports) of busbar trolley do not depend on the amplitude of k current harmonics, but depend only on their frequency. The level of voltage drop asymmetry for all forms of phase trolley busducts is caused by the asymmetry of their parameters. Among investigated L, W-, I-, U, X-forms of bus duct trolleys it was found that the most optimal form of steel and copper bus duct trolleys is the angular form of trolleys (L-form), which provides the least increment of active and reactive resistance of bus duct trolley, current harmonics, as well as the minimum level of their asymmetry between phases of bus duct trolleys.

Numerical study on the effect of fin length variation on the thermal performance of a bus duct conductor

This article presents a finite volume-based simulation study on the effect of fin length variation on the thermal performance of a bus duct conductor. The study was conducted by developing a numerical model using ANSYS FLUENT. IEC 60439-1 and IEC 60439-2 standards were employed as a guideline to conduct the experimental setup. It was found that increasing the fin length increases the total heat transfer rate. This is due to an increase in the surface area exposed to the fluid and a decrease in the thermal boundary layer thickness. However, it was observed that longer fin lengths contributed to greater frictional forces on the fluid that resulted in a drop in convective heat transfer coefficient. The current numerical study is expected to provide a better understanding of the effect of fin length on the thermal performance of a bus duct conductor.

Image Charge effect on Metallic Particle Movement in a single phase Gas Insulated Bus Duct with Dielectric Coated Enclosure

Image Charge effect on Metallic Particle Movement in a single phase Gas Insulated Bus Duct with Dielectric Coated Enclosure

АЛГОРИТМЫ УПРАВЛЕНИЯ ЭЛЕКТРИЧЕСКОЙ СЕТЬЮ ГИБРИДНОЙ СИСТЕМЫ ЭНЕРГООБЕСПЕЧЕНИЯ АНПА

The aim of the research was to control the electrical network of a hybrid power supply systemfor an autonomous underwater vehicle designed to travel over ultra-long distances over tensof thousands of kilometers. To overcome ultra-long distances, the urgent task is to minimize thespecific consumption of electricity, provided that all consumers are provided with electricity. Therelevance of the work is determined by the novelty of using a hybrid power supply system in autonomousunmanned underwater vehicles, consisting of heterogeneous sources of electricity operatingon different physical principles. Due to the lack of research to date, related to the control ofthe hybrid power supply system, coordinated with the modes of motion of the vehicle in a wide range of speeds, the problem arose of developing control algorithms for the hybrid power supplysystem. To solve the problem, the reasons for the change in current consumption during themovement of the device were analyzed, the necessary conditions for connecting consumers to thebus ducts were formed, including providing all consumers with electricity in full, excluding theexcess of the rated currents of each bus duct with consumption currents, minimizing electricitylosses when passing through the conductor and through the equipment. In this regard, the possibleconfigurations of the construction of the electrical network using conductors and equipment wereanalyzed, and losses on the current conductors and on the equipment used were estimated. Basedon the results of the research, a graph of consumers' connections to the conductors was formed,and to determine the way of connecting each consumer to the energy source through the powergrid, a connection path was determined that minimizes losses. The problem was formalized asfinding the shortest path in a graph, and Dijkstra's algorithm was used as a basis to solve it. Basedon the research results, algorithms were formed for the formation of ways to connect consumers toelectricity sources through the power grid and an algorithm for controlling the switching of keysin the power grid when the consumption currents change. The developed algorithms were implementedin software, and a numerical experiment was carried out using a simulation model. Theresults of the experiment showed the correctness of the developed algorithms, and can be furtherused for implementation in the devices under development for moving over ultra-long distances.

Effect of surfactant and particle size on thickness and hardness of nanocomposite coating Sn/Ag for bus duct conductor

Bus duct conductor is one of the key components under “Bus-Way-System”. Tin plated copper is the currently used material, but improvement is needed to reduce heat generation due to contact resistance and increase efficiency. In this study, silver nanoparticles (AgNP) of size 10 nm or 100 nm were ultrasonically dispersed in deionized water with the addition of sodium dodecyl sulfate (SDS) or cetyltrimethylammonium bromide (CTAB). The dispersed solution was then mixed with commercial stannous tin plating solution and nanocomposite AgNP/Sn coating were plated on copper substrate via ultrasonic assisted electroplating. Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-ray (EDX) and Knoop microhardness tester were used to study the effect of AgNP size and surfactant on the nanocomposite coating. From SEM cross section images, nanocomposite with 10 nm AgNP appeared denser than that of coating with 100 nm AgNP possibly due to smaller size particles are easier to be co-deposited. For addition of 10 nm AgNP, the thickness increased from 13.82 µm to 21.77 µm (without surfactant), 19.73 µm (with SDS), and 17.64 µm (with CTAB). As for Knoop Hardness (HK0.01), the value increased from 18.5 to 44.80 (without surfactant), 41.82 (with SDS) and 21.92 (with CTAB). It seems that SDS is better surfactant than CTAB for electroplating of AgNP/Sn coating due to higher hardness of coating. The results show successful fabrication of nanocomposite Sn/Ag coating with improvement in hardness compared to Sn coating, and thickness of coating is more than the thickness required for bus duct conductor, i.e more than 3 µm.

Analytical-Numerical Approach to the Skin and Proximity Effect in Lines with Round Parallel Wires

Power and communication lines with round wires are often used in electrical engineering. The skin and proximity effects affect the current density distribution and increase resistances and energy losses. Many approaches were proposed to calculate the effects and related quantities. One of the simplest approximate closed solutions neglects the dimensions of neighboring wires. In this paper, a solution to this problem is proposed based on the method of successive reactions. In this context, the solution with substitutive filaments is considered as the first approximation of the true solution. Several typical arrangements of wires in single-phase communication lines or three-phase bus ducts are considered to detect the limits of applicability of the first approximation. The error of the first approximation grows with wire radius to skin depth ratio and wire radius to wire spacing ratio. When the wire radius to skin depth ratio is up to 1, and the gap between the wires is above the wire radius, the error is at a level of 1%. However, lowering the distance and/or skin depth leads to a much larger error in the first approximation.

Diagnostic Examination of Isolated Bus Ducts

The paper offers a review of the procedure for diagnostic examination of isolated bus ducts with air insulation. Characteristic examples of isolated-phase and three-phase bus duct defects revealed during visual inspections and thermal imaging are provided. The results of lab-based measurements and acoustic location of partial discharge (PD) in the insulation systems with various defects (cracks, wet and contaminated surfaces) are discussed. Typical amplitude-frequency characteristics of the PD acoustic signals during the development of insulator defects (defect images) were obtained. The results of generator bus duct diagnostics using electromagnetic and acoustic instruments are presented.

Temperature Variation Research on Industrial Bus Duct System by MATLAB and FEA

This paper displays a test, numerical and FEA thermal model of the heat transfer process in an industrial bus duct system. The examination incorporates a mechanical properties of various bus bar materials and bus bar configurations. At that point the calculation has been produced to anticipate the temperature ascend in the bus bars and furthermore to think about the sizes of bus bar materials like copper and aluminum and changes in air speeds for both the copper and aluminum bus bar materials utilizing MATLAB and FEA unfaltering state thermal investigation in ansys. The outcomes acquired from the MATLAB estimation and FEA investigation has been compared. It has been discovered that constrained convection – opposite wind current lessens the power misfortune because of thermal generation is likewise diminished in the bus bar conductors.

Effect of Coating of Dielectric in a 3-Phase GIB with Particle Movement

The dielectric coating effect on the motion of the Particle inside a Gas Insulated Bus duct (GIB) of three phase using epoxy resin coating of dielectric inside f GIB outer enclosure of inner surface without image charge is presented in this paper. Simulation is performed by considering various parameters like drag, gravitational and the electrostatic forces acting on the particle and a mathematical model was derived. A 2nd order differential equation for the particle motion is solved and restitution coefficient was considered at each impact of particle with the GIB enclosure. At the particle locations, estimation of electric fields instantaneously was made by CSM. The particle motion in the absence of effect of image charge is considered in a 3-phase GIB with dielectric coating. For voltage levels like 220kV, 400kV, 600kV and 800kV class, the movement of radial in nature is found for particles like aluminum and copper inside GIB. Analysis of all the results were done and presented in this paper.

Field Stress Control of a Functionally Graded Disk Type Spacer in a Gas Insulated Bus Duct with Metal Inserts

High voltage electric utilities are hindered with certain difficulties like high stress distribution and insulation damage that are needed to be taken care for reliable operation of the system. In a Gas Insulated bus duct, high field stress along the spacer surface especially at the contact point of the conductor, insulator and gas (called triple junction) is a major factor affecting the insulation strength. Research studies of shaping the spacer were found effective in controlling the stress distribution but found to be complicated in real time application. In this paper, functionally graded materials of disc type spacer with different permittivity are proposed for controlled field stress distribution at the spacer surface. Electric field calculations with different gradings from high to low and U shape are done. Properly shaped metal inserts are incorporated to have a uniform stress distribution along the spacer.

The Magnetic Field and Impedances in Three-Phase Rectangular Busbars with a Finite Length

The paper presents an analytical method for calculating impedances of rectangular bus ducts. The method is based on the partial inductance theory—in particular, the impedance of rectangular busbars in a three-phase system with a neutral conductor is described. The results of resistances and reactances of these systems of multiple rectangular conductors were obtained. Skin and proximity effects were taken into account. The measurements of the impedance of shielded and unshielded high-current busducts of rectangular conductors were also carried out. The magnetic field of the busbars was determined with several methods.

에폭시 몰딩에 의한 부스바 온도 저감 효과에 관한 연구

As the number of large buildings and factories that consume a lot of electric power is increased, the use of bus ducts that can flow high current is increasing. The NSPB which is mainly used to connect the transformer and the switchboard has a structure in which a three-phase bus bars are spaced apart in a single metal enclosure. The bus bars are made of bare conductors or conductors coated with an epoxy powder or a heat-shrinkable tube. Bus ducts are required to have insulation characteristics for voltage, temperature characteristics due to current and mechanical characteristics due to short-circuit electromagnetic force.BR In this paper, temperature characteristics of epoxy molded bus bars were investigated through experiments. The maximum temperature change of the conductor with epoxy molding, the maximum conductor temperature change with the number of conductors and the space when the epoxy molding volume was the same and the maximum conductor temperature change with increasing current were compared.