Search results
1 – 10 of 259Jingbo Zhao, Yan Tao and Zhiming Sun
This paper aims to clarify voltage sourced converter’s (VSC’s) influence rules on the alternating current (AC) short-circuit current and identify the key factors, so as to propose…
Abstract
Purpose
This paper aims to clarify voltage sourced converter’s (VSC’s) influence rules on the alternating current (AC) short-circuit current and identify the key factors, so as to propose the short-circuit current suppression strategy.
Design/methodology/approach
This paper investigates the key factors which impact the short-circuit current supplied by the VSC based on the equivalent current source model. This study shows that the phase of the VSC equivalent current source is mainly affected by the type of fault, whereas the amplitude is mainly decided by the control mode, the amplitude limiter and the electrical distance. Based on the above influence mechanism, the dynamic limiter with short-circuit current limiting function is designed. The theoretical analysis is verified by simulations on PSCAD.
Findings
The short-circuit current feeding from VSC is closely related to the control mode and control parameters of the VSC, fault type at AC side and the electrical distance of the fault point. The proposed dynamic limiter can make VSC absorb more reactive power to suppress the short-circuit current.
Research limitations/implications
The dynamic limiter proposed in this paper is limited to suppress three-phase short-circuit fault current. The future work will focus more on improving and extending the dynamic limiter to the fault current suppression application in other fault scenarios.
Practical implications
The research results provide a reference for the design of protection system.
Originality/value
The key influence factors are conducive to put forward the measures to suppress the fault current, eliminate the risk of short-circuit current exceeding the standard and reduce the difficulty of protection design.
Details
Keywords
Khaoula Assadi, Jihane Ben Slimane, Hanene Chalandi and Salah Salhi
This study aims to focus on an adaptive method for fault detection and classification of fault types that trigger in three-phase transmission lines using artificial neural…
Abstract
Purpose
This study aims to focus on an adaptive method for fault detection and classification of fault types that trigger in three-phase transmission lines using artificial neural networks (ANNs). The proposed scheme can detect and classify several types of faults, including line-to-ground, line-to-line, double-line-to-ground, triple-line and triple-line-to-ground faults.
Design/methodology/approach
The fundamental components of three-phase current and voltage were used as inputs in the ANNs. An analysis of the impact of variations in the fault resistance, fault type and fault inception time was conducted to evaluate the ANNs performance. The survey compares the performance of the multi-layer perceptron neural network (MLPNN) and Elman recurrent neural network trained with the backpropagation learning technique to improve each of the three phases of the fault detection and classification process. A detailed analysis validates the choice of the ANNs architecture based on the variation in the number of hidden neurons in each step.
Findings
The mean square error, root mean square error, mean absolute error and linear regression are measured to improve the efficiency of the ANN models for both fault detection and classification. The results indicate that the MLPNN can detect and classify faults with a satisfactory performance.
Originality/value
The smart adaptive scheme is fast and accurate for fault detection and classification in a single circuit transmission line when faced with different conditions and can be useful for transmission line protection schemes.
Details
Keywords
Abdelmalek Saidoune, Hamza Houassine, Samir Bensaid, Nacera Yassa and Sadia Abbas
This paper aims to investigate the efficacy of teeth flux sensors in detecting, locating and assessing the severity of short-circuit faults in the stator windings of induction…
Abstract
Purpose
This paper aims to investigate the efficacy of teeth flux sensors in detecting, locating and assessing the severity of short-circuit faults in the stator windings of induction machines.
Design/methodology/approach
The experimental study involves inducing short-circuit winding turn variations on the induction machine’s stator and continuously measuring the RMS values across teeth flux sensors. Two crucial steps are taken for machine diagnosis: measurements under load operating conditions for fault detection and measurements under no-load conditions to determine fault location and severity.
Findings
The experimental results demonstrate that the proposed approach using teeth flux sensors is reliable and effective in detecting, locating and evaluating the severity of stator winding faults.
Research limitations/implications
While this study focuses on short-circuit faults, future research could explore other fault types and alternative sensor configurations to enhance the comprehensiveness of fault diagnosis.
Practical implications
The methodology outlined in this paper holds the potential to significantly reduce maintenance time and costs for induction machines, leading to substantial savings for companies.
Originality/value
This research contributes to the field by presenting an innovative approach that uses teeth flux sensors for a comprehensive fault diagnosis in induction machines. The originality lies in the effectiveness of this approach in providing reliable fault detection, location and severity evaluation.
Details
Keywords
Raya A.K. Aswad and Bassim M.H. Jassim
This paper aims to introduce the usage of sensitivity analysis (SA) for the problem of faults identification in three-phase induction motors (IMs). These motors are susceptible to…
Abstract
Purpose
This paper aims to introduce the usage of sensitivity analysis (SA) for the problem of faults identification in three-phase induction motors (IMs). These motors are susceptible to different kinds of faults that should be detected in a proper time to keep the systems working in a safety environment.
Design/methodology/approach
One of the effective approaches for faults identifications, which is presented in the literature, is a model-based strategy. This strategy mainly depends on using a software model to make an identification decision. Therefore, this work intends to examine the model sensitivity towards variables’ variation. The SA toolbox of Matlab R2017b package is used for this purpose since the Matlab software is a well-known environment, and it is easy for a nonstatistical person to deal with it. As a study case, open-circuit and stator inter-turn faults in the stator windings of a three-phase IM have been chosen.
Findings
The results show that the model-based strategy is considerably speed up by up to 30% when neglecting the trivial model’s parameters with the same accurate identification decision as compared with the results of this strategy without using the SA.
Originality/value
The novelty of this work is summarized in devoting the usage of SA in the field of faults identification to enhance the speed of final decision.
Details
Keywords
This paper aims to explore the process of implementing solar photovoltaic (PV) systems in construction to contribute to the understanding of systemic innovation in construction.
Abstract
Purpose
This paper aims to explore the process of implementing solar photovoltaic (PV) systems in construction to contribute to the understanding of systemic innovation in construction.
Design/methodology/approach
The exploratory research presented is based on qualitative data collected in workshops and interviews with 76 construction- and solar-industry actors experienced in solar PV projects. Actor-specific barriers were identified and analysed using an abductive approach.
Findings
In light of established definitions of systemic innovation, the process of implementing solar PV systems in construction involves challenges regarding technical and material issues, competencies, and informal and formal institutions. The specificities of this case highlight the necessity of paying attention to details in the process and to develop knowledge of systemic innovation in construction since the industry’s involvement in addressing societal challenges related to the energy transition will require implementing such innovations much more in the future.
Practical implications
New knowledge of solar PV systems as an innovation in professional construction is collected, enabling the adaptation of management strategies for its implementation. This knowledge can also be applied generally to other challenges encountered in highly systemic innovation implementation. Solar industry actors can gain an understanding of solar-specific challenges for the construction industry, challenges for which they must adapt their activities.
Originality/value
The exploration of actor-specific experiences of solar PV projects has resulted in a novel understanding of this specific innovation and its implementation. The findings illustrate a case of a high level of systemic innovation and the need to use a finer-grained scale for classification when studying innovation in construction.
Details
Keywords
Ali Hashemi, Parsa Yazdanpanah Qaraei and Mostafa Shabanian
An excessive increase in temperature will reduce the lifespan and even burn the coil. The variety of materials in the structure of the electromagnet along with its multi-layer…
Abstract
Purpose
An excessive increase in temperature will reduce the lifespan and even burn the coil. The variety of materials in the structure of the electromagnet along with its multi-layer winding creates a complex and heterogeneous thermal structure. There are very few researches that are completely focused on the thermal analysis of electromagnets. The purpose of this paper is to provide an accurate, yet fast and simple method for the thermal analysis of cylindrical electromagnets in both transient and steady-state modes. For this purpose, a thermal equivalent circuit (TEC) is presented based on the nodding approach.
Design/methodology/approach
The results of TEC analysis of cylindrical electromagnet, for two orthogonal and orthocyclic winding coil technologies, were compared with the results of the thermal simulation in COMSOL. The authors also built a laboratory model of the cylindrical electromagnet, similar to those analyzed and simulated, and measured the temperature in different parts of it.
Findings
The comparison of the results obtained from different methods for the thermal analysis of the cylindrical electromagnet indicates that the proposed TEC has an error of less than 2%. The simplicity and high accuracy of the results are the most important advantages of the proposed TEC.
Originality/value
Comparing the information and results related to winding schemes, indicates that the orthogonal winding has less cost and weight due to the shorter length of the wire used. On the other hand, orthocyclic winding generates lower temperature and has more lifting force, and is simpler to implement. Therefore, in practice, orthocyclic winding technology is usually used.
Details
Keywords
An Thi Binh Duong, Uyen My Diep, Paulo Sampaio, Maria Carvalho, Hai Thanh Pham, Thu-Hang Hoang, Dung Quang Truong and Huy Quang Truong
This research aims to specialise in the investigation of risk management for service-oriented manufacturing supply chains via two stages, highlighting its differences from…
Abstract
Purpose
This research aims to specialise in the investigation of risk management for service-oriented manufacturing supply chains via two stages, highlighting its differences from manufacturing. The research article is commenced by executing an encyclopedic review of earlier research to ascertain the distinctive traits of service-oriented manufacturing supply chains and identify prevalent risks. Secondly, an empirical study in the construction field, amongst the industry hardest struck in the mist of the COVID-19 epidemic, is conducted to thoroughly inspect the resonant effect of these risks on service-oriented manufacturing supply chain performance.
Design/methodology/approach
In this study, to validate the resonant effect mechanism, a thorough assessment is undertaken by juxtaposing theoretical model to a newly constructed comparative model that encompasses the single effects of risks on supply chain performance.
Findings
63% variance of service-oriented manufacturing supply chain performance was showcased by the resonant effect model, compared with 46.3% in the comparative model. Moreover, each risk exerts a more glaringly significant impact on supply chain performance, asserting the mechanism of the resonant influence. Another noteworthy result involves the demand risk possessing a low effect on supply chain performance, thus emphasising the superiority of service-oriented manufacturing supply chains.
Research limitations/implications
Future research endeavours should hinge on the optimal “resonant” model explosion, thereby foreseeing and alleviating worst-case scenarios to guarantee the robustness and resilience of supply chain networks.
Practical implications
Indubitably, reducing the intensity of the resonant effect revolves around lowering the coefficient of “a,” thereby restricting/eliminating the link among risks. Therefore, the suggested resonant impact model might thus serve as “a road map”. In light of the aforementioned considerations, it is advisable that supply chain executives employ supply chain management tactics namely avoidance, prediction, and postponement, but only after meticulous consideration the costs and benefits of adopting such strategies.
Originality/value
The service-oriented manufacturing supply chain features and advantages have been analysed and explained throughout the article. The data gathered during the COVID-19 pandemic is a captivating and topical point of this paper.
Details
Keywords
This paper aims to investigate how augmented reality (AR) technology is adopted in the library to transform it into an immersive and interactive platform and highlights the future…
Abstract
Purpose
This paper aims to investigate how augmented reality (AR) technology is adopted in the library to transform it into an immersive and interactive platform and highlights the future possibilities of the application of AR in libraries.
Design/methodology/approach
The study examines the current applications of AR in the library by consulting related literature and analyzing different library websites covering diverse geographical areas.
Findings
The paper with examples summarizes the current library practices of using AR technology and focuses on the AR-supported major library initiatives – right from document tracking, inventory management, wayfinding, supporting innovation and research, developing information literacy skills, etc.
Originality/value
The paper explores the possibility of improving user experience in the library by introducing AR applications and engaging users in an interactive and captivating environment.
Details
Keywords
Godfred Fobiri, Innocent Musonda and Franco Muleya
Digital data acquisition is crucial for operations in the digital transformation era. Reality capture (RC) has made an immeasurable contribution to various fields, especially in…
Abstract
Purpose
Digital data acquisition is crucial for operations in the digital transformation era. Reality capture (RC) has made an immeasurable contribution to various fields, especially in the built environment. This paper aims to review RC applications, potentials, limitations and the extent to which RC can be adopted for cost monitoring of construction projects.
Design/methodology/approach
A mixed-method approach, using Bibliometric analysis and the PRISMA framework, was used to review and analyse 112 peer-reviewed journal articles from the Scopus and Web of Science databases.
Findings
The study reveals RC has been applied in various areas in the built environment, but health and safety, cost and labour productivity monitoring have received little or no attention. It is proposed that RC can significantly support cost monitoring owing to its ability to acquire accurate and quick digital as-built 3D point cloud data, which contains rich measurement points for the valuation of work done.
Research limitations/implications
The study’s conclusions are based only on the Scopus and Web of Science data sets. Only English language documents were approved, whereas others may be in other languages. The research is a non-validation of findings using empirical data to confirm the data obtained from RC literature.
Practical implications
This paper highlights the importance of RC for cost monitoring in construction projects, filling knowledge gaps and enhancing project outcomes.
Social implications
The implementation of RC in the era of the digital revolution has the potential to improve project delivery around the world today. Every project’s success is largely determined by the availability of precise and detailed digital data. RC applications have pushed for more sustainable design, construction and operations in the built environment.
Originality/value
The study has given research trends on the extent of RC applications, potentials, limitations and future directions.
Details
Keywords
Tingting Tian, Hongjian Shi, Ruhui Ma and Yuan Liu
For privacy protection, federated learning based on data separation allows machine learning models to be trained on remote devices or in isolated data devices. However, due to the…
Abstract
Purpose
For privacy protection, federated learning based on data separation allows machine learning models to be trained on remote devices or in isolated data devices. However, due to the limited resources such as bandwidth and power of local devices, communication in federated learning can be much slower than in local computing. This study aims to improve communication efficiency by reducing the number of communication rounds and the size of information transmitted in each round.
Design/methodology/approach
This paper allows each user node to perform multiple local trainings, then upload the local model parameters to a central server. The central server updates the global model parameters by weighted averaging the parameter information. Based on this aggregation, user nodes first cluster the parameter information to be uploaded and then replace each value with the mean value of its cluster. Considering the asymmetry of the federated learning framework, adaptively select the optimal number of clusters required to compress the model information.
Findings
While maintaining the loss convergence rate similar to that of federated averaging, the test accuracy did not decrease significantly.
Originality/value
By compressing uplink traffic, the work can improve communication efficiency on dynamic networks with limited resources.
Details