Transformer Manufacturers Research Articles

MCDM Approach for Locating Automatic Teller Machines: An Application in Turkish Banking Sector

Although there is an increase in the use of alternative channels through which the service offered by bank ATMs (Automated Teller Machine) can be met due to technological developments, branching remains important for banks in terms of increasing the loyalty of existing customers to the bank, acquiring new customers and maintaining communication with all customers. The location to be determined for ATM placement may vary depending on many factors. In this study, a simple and easily usable method is presented to find the most suitable location for bank branches. The purpose of this study report is to compare the solutions of the case analysis with PROMETHEE II method used in the selected article and the other method which is ELECTRE II. PROMETHEE II method was solved by the authors of the selected article, ELECTRE method by the authors of this report. The case study was conducted with data from the decision maker in a transformer manufacturing organization in India. Methods give different results for 3 identified sustainable concepts (S1, S2, S3).

Operation State Identification Method for Converter Transformers Based on Vibration Detection Technology and Deep Belief Network Optimization Algorithm

The converter transformer is a special power transformer that connects the converter bridge to the AC system in the HVDC transmission system. Due to the special structure of the converter transformer, it is necessary to test its operation state during its manufacture and processing to ensure the safety of its future connection to the grid. Numerous studies have shown that vibration signals in transformers can reflect their operating state. Therefore, in order to achieve an effective identification of the operation state of the converter transformer, this paper proposes a method for identifying the operation state of the converter transformer based on vibration detection technology and a deep belief network optimization algorithm. This paper firstly describes the background, principle and application of vibration detection technology, using vibration measurement systems with piezoelectric acceleration sensors, piezoelectric actuators and data acquisition instruments to collect vibration signals at different measurement points on the converter transformer in states of no-load and on-load. By analyzing the time-frequency characteristics of the vibration signals, fast Fourier transform (FFT), wavelet packet decomposition (WPD) and time domain indexes (TDI) are combined into a fused feature extraction method to extract the eigenvalues of the vibration signals, so that the fused eigenvectors of the signals can be constructed. Considering the excellent performance of deep learning in classification, the deep belief network is used to classify the signals’ eigenvectors. To effectively improve the network classification efficiency, the sparrow search algorithm was introduced to build a mathematical model based on the behavioral characteristics of sparrow populations and combine the model with a deep belief network, so as to achieve adaptive parameter optimization of the network and accurate classification of the signals’ eigenvectors. The proposed method is applied to a 500 kV converter transformer for experimental verification. The experimental results show that the fused feature extraction method was able to fully extract the features of the vibration signal, and the deep belief network optimization algorithm had higher classification accuracy and better operational efficiency, and was able to effectively achieve accurate identification of the operation state of the converter transformer. In addition, the method achieved a precision response to the detection results of the vibration sensors, contributing to future improvements in converter transformer manufacturing technology.

Design Implication of a Distribution Transformer in Solar Power Plants Based on Its Harmonic Profile

This article presents a comparative analysis for the design considerations for a solar power generation transformer. One of the main existing problems in transformer manufacturing is in the renewable energy field, specifically the solar power generation, where the transformer connected to the inverter is operated under a certain harmonic content and operating conditions. The operating conditions of the transformer connected to the inverter are particularly unknown for each solar power plant; thus, the transformer will be subject to a particular harmonic content, which is defined by the inverter of the solar power plant. First, the fundamental calculations for solar power plant transformer and the proposed methodology for the design calculation of the distribution pad-mounted three phase transformer are presented. Then, a design study case is described where a distribution transformer and an inverter of a particular solar power plant are used for the analysis. Next, the transformer under analysis is modeled using finite element analysis in ANSYS Maxwell® software, where the transformer will be designed for a non-harmonic and harmonic content application. Lastly, the main design parameters, flux density, the core losses and the winding excitation voltage of the transformer are calculated and presented in results and discussion section.

Optimal Design, Re-engineering and Testing of a 50:5A Current Transformer for Medium Voltage Industrial Requirements

The current transformer is one of the types of instrument transformer which is designed in such a manner so as to produce a current in its secondary circuit which in turn proportional to the current flowing through it’s primary circuit. It is one of the components that needs to be installed inside the electrical panel board in order to measure the current flow through each phase of the three phase system inside the panel. Usually these electrical panel boards were designed by electrical based industries. One of such industries which was in need of a 50:5 ratio current transformer had handed over the current transformer design and manufacturing as an industrial work to the authors. In this paper the authors deal with the optimal design and re-engineering and testing of the current transformer that is used in the measurement of current.

The calculate of current transformers with combined magnetic cores

The manufacture of current transformers is associated with many design constraints, which include the restricted dimensions of its installation places, requirements for the accuracy class, as well as the limitation on the safety factor or the minimum factor of the accuracy limit factor. In a design sense of current transformers, these requirements are contradictory, which resulting in a flexible approach to the manufacture of current transformers. The use of combined magnetic cores can be referred to one of these areas, in other words magnetic cores consisting of materials with different magnetic properties, which allows to obtain unique magnetic properties that are inaccessible when using magnetic cores of the same type (material), thus providing a rational model of production. The article presents a feature of calculating of current transformer with combined magnetic cores.

Differentiation of Service Delivery Priorities in the International Industrial Markets Applied Research Conducted with a Transformer Manufacturer Company “X”

Differentiation of Service Delivery Priorities in the International Industrial Markets Applied Research Conducted with a Transformer Manufacturer Company “X”

ASSESSMENT OF LUNG FUNCTION STATUS OF WORKERS AT A TRANSFORMER MANUFACTURING PLANT IN SELANGOR, MALAYSIA

Transformer manufacturing industry uses volatile organic compounds (VOCs) containing materials such as varnish which can cause adverse health effects to human. Exposure to a high level of VOCs could disrupt the normal functions of a human lung.Therefore, this study was conducted to evaluate the status of lung functions of the workers exposed to VOCs at a transformer manufacturing plant in Selangor. The volatile organic compounds (VOCs) concentration in the office and production area was measured using direct-reading method and 60 subjects were selected to undergo the lung function test. The FVC and FEV1 values showed significant difference (p<0.05) between the exposed group and the non-exposed group. The mean readings of FVC (69.07±12.58) and FEV₁ (72.90±10.46) of the exposed groups were lower than the non-exposed group, which were 81.47±9.78 and 84.23±9.07, respectively. In contrast to the FEV1/FVC parameters, the non-exposed group (102.93 ± 7.17) showed lower mean values than the exposed group (105.90±8.98). Besides that, the nasal symptoms showed significant differences (p<0.05) between the exposed and non-exposed group. The demographic data of the exposed group showed no association with the lung function status of the exposed group workers. However, the lung functions of the exposed group were influenced by the concentration of VOCs in the production area. High concentration of VOCs may cause detrimental effects on the lung functions. Therefore, management or employers in the industry should always be aware of the effects of VOCs, and take appropriate steps to ensure the safety and welfare of the employees.

Laser writing of electronic circuitry in thin film molybdenum disulfide: A transformative manufacturing approach

Electronic circuits, the backbone of modern electronic devices, require precise integration of conducting, insulating, and semiconducting materials in two- and three-dimensional space to control the flow of electric current. Alternative strategies to pattern these materials outside of a cleanroom environment, such as additive manufacturing, have enabled rapid prototyping and eliminated design constraints imposed by traditional fabrication. In this work, a transformative manufacturing approach using laser processing is implemented to directly realize conducting, insulating, and semiconducting phases within an amorphous molybdenum disulfide thin film precursor. This is achieved by varying the incident visible (514 nm) laser intensity and raster-scanning the thin film a-MoS2 sample (900 nm thick) at different speeds for micro-scale control of the crystallization and reaction kinetics. The overall result is the transformation of select regions of the a-MoS2 film into MoO2, MoO3, and 2H-MoS2 phases, exhibiting conducting, insulating, and semiconducting properties, respectively. A mechanism for this precursor transformation based on crystallization and oxidation is developed using a thermal model paired with a description of the reaction kinetics. Finally, by engineering the architecture of the three crystalline phases, electrical devices such as a resistor, capacitor, and chemical sensor were laser-written directly within the precursor film, representing an entirely transformative manufacturing approach for the fabrication of electronic circuitry.

Design optimisation for distance between additional and tap winding in high‐voltage transformers

The transformer is one of the main components in the power network and transformer windings are one of the most expensive elements in the power transformer. Optimisation of winding distances is one of the most important parameters during the manufacturing of transformer. The distance between the windings in the two winding transformers is well known to transformer designers and manufacturers. However, insulation of the high voltage transformer with additional winding and tap winding is still a major problem for transformer designers. In this study, the additional winding to tap winding distance optimisation is made for a high voltage power transformer. Optimisation of the transformer's windings just not minimises the cost of the transformer but also increases the lifetime of the transformer. With additional winding and tap winding in high-voltage transformers, insulation distance is a major concern for minimising the cost and size of the high voltage transformer. In this study, an approach is made to balance the cost, size, and safety of high voltage transformers. The optimised distance and position between tap winding and additional winding are determined by using the finite element analysis. The finite element method results were also verified by making a prototype transformer.

Assessment of Exposure to Indoor Air Pollutants at the Transformer Manufacturing Plant in Selangor, Malaysia

Assessment of Exposure to Indoor Air Pollutants at the Transformer Manufacturing Plant in Selangor, Malaysia

Power Losses Analysis in a Three-Phase Distribution Transformer Using Artificial Neural Networks

This research article presents the analysis of power losses in a three - phase distribution transformer, 100 kVA 22 kV-400/230V by using artificial neutral networks that can analyze the power losses in distribution transformer faster and use less variables than the original method. The measurement data were collected 100,000 sets at the transformer manufacturer factory by setting the current flow from 1% to 100% at temperature 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55°C, 60 °C, 65 °C, 70 °C, and 75 °C to calculate the power losses in a distribution transformer. The collected data were divided 80,000 sets to use for training in order to find parameters of artificial neutral networks and 20,000 sets were used for the artificial neutral networks input in order to calculate power losses in a distribution transformer. From the power losses in the distribution transformer of artificial neutral networks testing compared with the calculated valued from the measurement. The percentage error was at the satisfactory level and can be applied to design the testing of power losses in the distribution transformer in the future.

Moisture dynamics in natural-ester filled transformers

Due to the global trend in the industry to work towards sustainability and clean energy, utilities and transformer manufacturers focus on the design of environmentally friendly devices. In this context, the use of natural esters as transformer’s liquid insulation is becoming an habitual practice in distribution transformers. These fluids make possible the operation of transformers with lower fire risk, what is important for certain applications. Additionally natural esters are biodegradable and their application minimizes the risk of soil contamination in case of fluid’s leak. One of the differential characteristics of ester fluids is that they have higher affinity for moisture than mineral oils, absorbing masses of water up to ten times greater than conventional insulating fluids under similar working conditions. This fact changes the water distribution between the solid and liquid insulation that is typically found in mineral-oil filled transformers. Moisture content in insulating materials remains as one of the most important parameters determining the life cycle of transformers, hence the importance of fully understanding its behaviour. Although many actions are being taken to spread the use of ester fluids, not many works about the performance of water in ester-cellulose systems haven been published to date.In this work, an analysis on the moisture dynamics in transformers insulated with natural esters is presented. In the first part of the paper the main parameters that influence the moisture distribution between oil and paper are obtained either for the case of an ester or a mineral oil being used as insulating fluids. Then, simulations are carried out in which different temperature profiles are assumed and the evolution of the moisture distribution between the solid and liquid insulation is analysed.The reported parameters together with the theoretical model proposed in this work can be used to evaluate the maximum admissible load of transformers insulated with natural ester taking into account not only the thermal aspects but also the moisture dynamics of the oil-paper insulation. The application of the presented approach can lead to a more reliable diagnosis of the transformer as moisture-related critical points could be identified and subsequent actions be taken to correct the risk. Identification of critical events, such as the presence of excessive moisture in the liquid insulation with the subsequent risk of partial discharges, breakdown or formation of water in liquid state, will help the transformer operator to take decisions that make possible a safer transformer exploitation.

Applying HF and VHF/UHF Partial Discharge Detection for Distribution Transformer

This paper represents application of high frequency (HF) and very high frequency/ultrahigh frequency (VHF/UHF) partial discharge (PD) detection for a distribution transformer. A capacitive sensor is used to detect the HF electric field caused by charge transfer inside oil–paper insulation due to PD at the defect site, and an electromagnetic sensor or antenna is used for detecting electromagnetic PD transients in the air outside the investigated transformer in the near-field region. Three types of artificial PD sources in air and insulating liquid, which are corona discharge, surface discharge and air void discharge in pressboard, were investigated. Three identical distribution transformers were rated at 22 kV, 400 V and 50 kVA, and were designed and constructed. The first transformer was filled with mineral oil, the second was filled with natural ester and the third was filled with palm oil. The PD generated by the air-filled voids in the insulating papers and pressboards of these transformers with five different conditions were investigated, i.e., non-impregnated paper, impregnated paper for 3 hours, 6 hours, 9 hours and 12 hours. The impregnation process was done with 65°C liquid temperature, and the pressure in the oven was around 5 mbar. From the experimental results, it can be concluded that the electromagnetic PD transients radiated from the corona discharge of both high-voltage (HV) and low-voltage sides in the air are in the VHF range, and surface discharge frequency is extended up to the UHF range. For the PD in the insulating liquid, the phase resolved PD (PRPD) pattern in the HF range is a valuable tool to characterize the PD sources. The PD in an air-filled void inside the insulating paper of the mineral oil transformer is obviously different compared with those of the natural ester transformer and the palm oil transformer. For the manufacturing of distribution transformers in this research, it is found that after the paper insulation is dried out, the impregnation process for a period of 9 hours is suitable for improving the oil–paper insulation with an acceptable PD level. This paper is the cross-field application by applying the antenna and communication theory for detecting the discharge problems in HV equipment.

3D-printed Patient-specific Spine Implants: A Systematic Review.

Systematic review. To review the current clinical use of 3-dimensional printed (3DP) patient-specific implants in the spine. Additive manufacturing is a transformative manufacturing method now being applied to spinal implants. Recent innovations in technology have allowed the production of medical-grade implants with unprecedented structure and customization, and the complex anatomy of the spine is ideally suited for patient-specific devices. Improvement in implant design through the process of 3DP may lead to improved osseointegration, lower subsidence rates, and faster operative times. A comprehensive search of the literature was conducted using Ovid MEDLINE, EMBASE, Scopus, and other sources that resulted in 1842 unique articles. All manuscripts describing the use of 3DP spinal implants in humans were included. Two independent reviewers (N.W. and N.E.S.) assessed eligibility for inclusion. The following outcomes were collected: pain score, Japanese Orthopedic Association (JOA) score, subsidence, fusion, Cobb angle, vertebral height, and complications. No conflicts of interest existed. No funding was received for this work. A total of 17 studies met inclusion criteria with a total of 35 patients. Only case series and case reports were identified. Follow-up times ranged from 3 to 36 months. Implant types included vertebral body replacement cages, interbody cages, sacral reconstruction prostheses, iliolumbar rods, and a posterior cervical plate. All studies reported improvement in both clinical and radiographic outcomes. 11 of 35 cases showed subsidence >3 mm, but only 1 case required a revision procedure. No migration, loosening, or pseudarthrosis occurred in any patient on the basis of computed tomography or flexion-extension radiographs. Results of the systematic review indicate that 3DP technology is a viable means to fabricate patient-matched spinal implants. The effects on clinical and radiographic outcome measures are still in question, but these devices may produce favorable subsidence and pseudoarthrosis rates. Currently, the technology is ideally suited for complex tumor pathology and atypical bone defects. Future randomized controlled trials and cost analyses are still needed. IV-systematic review.

Development of a superconducting transformer for high current conductor testing

Critical current (Ic) tests on superconducting conductors require currents on the order of tens of kilo-amperes in combination with sub-microvolt resolution voltage measurements. Instead of traditional expensive DC power supply and complicated current leads, a superconducting transformer has been developed to feed the test sample with current up to 30 kA. The transformer consists of two concentric layer-wound superconducting solenoids with the primary coil inside the secondary. In order to reduce the influence by stray field of background magnet and transformer, a hall array with two hall sensors symmetrically distributed around the secondary conductor is used to achieve accurate secondary current measurement. This paper describes the design and manufacturing of transformer, including accurate secondary current measurement method. The first test results are also presented. The superconducting transformer system enables fast, high resolution, economic and safe tests of high current conductors.

A classification-based approach for integrated service matching and composition in cloud manufacturing

Cloud manufacturing has been acknowledged as a transformative manufacturing paradigm aiming towards producing highly customized products via sharing distributed manufacturing resources and capabilities. One of the pivotal challenges regarding the practical realization of this idea is the process of matching manufacturing resources with personalized service demands. This problem contains two main steps: (1) retrieval of functionally similar services through assessing semantic similarity between resources’ and subtasks’ descriptions and (2) optimal composition of subtasks according to non-functional quality of service (QoS) indexes. However, almost all the research work in the field so far has focused on tackling each of these dimensions individually which barely represents actual conditions of the cloud manufacturing paradigm. To this end, this paper aims towards a novel integrated approach that first, successfully retrieves candidate sets for each corresponding subtask via implementing five classification algorithms and using TF-IDF (term frequency–inverse document frequency) vectors extracted from the manufacturing capability data. Then, optimal composite services are obtained for each scenario by using two well-known metaheuristic algorithms. Results obtained from the experiments have proven the advantages of this method resulting in a more comprehensive and realistic way for dealing with the service composition problems.

Exploratory Analysis of the Market Trend of Power Transformers in Mexico for Manufacturing Sector for Exportation

The electric sector continues in constant development, the requirements that the market demands must be included in the design and manufacturing processes of the components that make up the grid, such as the Power Transformers. The objective of the research presented is to know the general characteristics that impact the design and manufacture of transformers in Mexico, for which, four stages were identified as part of the General Methodology, which includes the niche market, the companies that manufactures in Mexico, the volume of exported transformers, as well as the suppliers and raw materials that are necessary for their production. For which a literary research was carried out, also the consultation in secondary sources, field research in a manufacturing company, and analysis of statistical data through the Minitab program, and a comparison of the bill of materials (BOM) of the transformers with the highest export index. All this will allow us to know, influence and improve the design and manufacturing of transformers.

Influence of Various Temperatures on the Drying Time of 220/66 KV Transformer Insulations in Vapour Phase Drying Process

Cellulose based insulation in the form of different papers and pressboard play a vital role in transformer manufacturing as very high level of voltages are encountered during transformer operation. Cellulose being hygroscopic in nature contains 8-10% moisture by weight. The life of a transformer is critically dependant on the state of cellulose insulation so much so that, paper with 1.5% moisture content ages 10 times faster than with only 0.3% moisture. For obvious reasons, it is very important that the moisture is removed from transformer insulation. As of today, the latest technology available for this moisture extraction is the vapour phase drying process. This paper evaluates the influence of temperatures at various locations on the drying time of two 220kv transformer insulations in vapour phase drying process.

Measurement of the leakage flux in the vicinity of a transformer core

PurposeThis study presents a new method for the detection of faults in large transformer cores. It is based on the analysis of leakage flux components in the vicinity of the sheet stack. The purpose of this study is to provide a nondestructive analysis tool for transformer cores during the assembly process to detect accidental defects such as inter-laminar short circuits.Design/methodology/approachThe different components of the leakage flux allow localization of the fault in the stack and also permit to assess its severity. Out of the many kinds of defects which may appear in a transformer core, this method only detects those which actually cause an increase in the transformer’s global iron losses, which are thus the most detrimental.FindingsThe proposed method allows a more efficient control of the quality of the cores during their manufacturing process. Until now, it was only possible to know the quality of the core when the transformer was fully assembled.Research limitations/implicationsThe accuracy of the method depends on the size of the defect and may request many measurements to give usable information.Practical implicationsControlling iron losses in a core during its construction avoids heavy dismantling operations, both financially and temporally.Originality/valueThis method can help transformer manufacturers optimize their building process. In addition, the method remains effective regardless of the size of the core considered.

Efficiency and Cost Based Multi-optimization and Thermal/Electromagnetic Analyses of 3-Phase Dry-Type Transformer

ABSTRACTDry-type transformers are one of the most significant devices used in the conversion, transmission and management process of the electricity. In practice, the electrical energy conversion entails energy losses such as heat, electromechanical and electromagnetic losses during the transformation. Hence, primary importance is the efficiency of energy conversion for a device that converts AC voltage from one value to another with the same frequency. Therefore, this study offers the best 3-phase dry-type transformer modelling interested in cost and efficiency related to transformer losses and useful energy conversion. Transformer manufacturing industries will produce a low cost and more efficient dry-type transformer by using electromagnetic/thermal analyzing and multi-optimization methods. Firstly, a 250 VA 380/110 V 3-phase cast resin core type transformer is modelled by an electromagnetic field simulator software programme called as ANSYS/Maxwell so the transformer is analyzed in detail in terms of the thermal and electromagnetic. In addition, the cost and efficiency values are optimized based on the current density (s) and C coefficient parameters by the multi-optimization method. Secondly, the transformer model is analyzed as thermal and electromagnetic at the end of the simulation results. Finally, the transformer is tested experimentally so the test results are confirmed by the simulation results considering the measurements. It is hoped that this study will contribute to transformer designers and operators interested in the conversion, transmission and management of the electrical energy.