Lei Xiong, Hongjun Shi and Qixin Zhu
This study aims to construct a novel maximum power tracking control system for the direct drive permanent magnet synchronous generator (PMSG) of the wind energy conversion system…
Abstract
Purpose
This study aims to construct a novel maximum power tracking control system for the direct drive permanent magnet synchronous generator (PMSG) of the wind energy conversion system (WECS) to solve the following problems: how to effectively eliminate the system’s model parameter disturbances and speed up the dynamic performance of the system; and how to eliminate harmonics in WECS under different wind speeds.
Design/methodology/approach
To obtain the maximum output power of PMSG at WECS under different wind speeds, the following issues should be considered: (1) how to effectively eliminate the system’s model parameter disturbances and speed up the dynamic performance of the system; and (2) how to suppress system harmonics. For Problem 1, adding d–q compensation factors to active disturbance rejection control (ADRC) for the current loop realizes the d–q axis decoupling control, which speeds up the dynamic performance of the system. For Problem 2, the resonant controller is introduced into the ADRC for the current loop to suppress harmonic current in WECS under different wind speeds.
Findings
The simulation results demonstrate that the proposed control method is simpler and more reliable than conventional controllers for maximum power tracking.
Originality/value
Compared with traditional controllers, the proposed controller can speed up the dynamic performance of the system and suppress the current harmonic effectively, thus better achieving maximum power tracking.
Details
Keywords
Hongjun Shi, Lei Xiong, Xuchen Nie and Qixin Zhu
This paper aims to mainly discuss how to suppress the disturbances accurately and effectively in the wind energy conversion system (WECS) of the direct drive surface mount…
Abstract
Purpose
This paper aims to mainly discuss how to suppress the disturbances accurately and effectively in the wind energy conversion system (WECS) of the direct drive surface mount permanent magnet synchronous generator (SPMSG).
Design/methodology/approach
The disturbances in wind energy conversion system have seriously negative influence on the maximum power tracking performance. Therefore, a model predictive control (MPC) method of model compensation active disturbance rejection control (ADRC) strategy in parallel connection is designed, which optimizes the speed tracking performance compared with the existing control strategy of MPC and ADRC in series connection. Based on the traditional ADRC, a multi parameter model compensation ADRC strategy is added to better estimate the disturbances. At the same time, a torque feedback strategy is added to compensate the disturbances caused by load torque and further optimize the speed loop tracking performance.
Findings
The simulation results show that the designed control method has advantages than the traditional control method in compensating the disturbances and tracking the maximum power more effectively.
Originality/value
The simulation results show that the designed control method is superior to the traditional proportional control method, which can better compensate the internal and external disturbances and track the maximum power more effectively.
Details
Keywords
We all understand the everlasting harmful effects of pollution. A larger proportion of this pollution gets generated from industrial units due to use of backward technologies…
Abstract
We all understand the everlasting harmful effects of pollution. A larger proportion of this pollution gets generated from industrial units due to use of backward technologies along with intentional or unintentional economic policies that has allowed such industries to grow over the years. Many of these industries are poor, in many cases, they do not have the ability to install abatement technologies or use emission-free green technologies for their huge cost. In many cases, they do not do so intentionally just to enjoy higher profit and due to faulty planning. But, the pollution generated from such industries makes us all suffer, especially those who live in those industrial areas. They are more exposed to the emission directly. Again, growing consensus among people about pollution has increased the consumption of eco-friendly, less-polluting products which could have a wide-ranging impact on the production techniques and can force the producers to change their production techniques, In this chapter, by applying contingent valuation method (CVM), the authors have looked to capture how far people of two very renowned industrial belts in West Bengal, Howrah and Barrackpore, are willing to contribute to the reduction of such emission level by consuming eco-friendly products and paying the emitting producers to force them to adopt pollution-free technology. The authors have applied close-ended dichotomous choice (DC) bidding technique by using logit regression and have also applied open-ended bidding process by using ordinary least square (OLS) method. In both cases, the authors have found the mean willingness to pay (WTP) is quite high which shows that people are very much willing to move towards using eco-friendly goods and technologies.
Details
Keywords
Chenfeng Xiong, Xiqun Chen and Lei Zhang
This chapter explores a descriptive theory of multidimensional travel behaviour, estimation of quantitative models, and demonstration in an agent-based microsimulation.
Abstract
Purpose
This chapter explores a descriptive theory of multidimensional travel behaviour, estimation of quantitative models, and demonstration in an agent-based microsimulation.
Theory
A descriptive theory on multidimensional travel behaviour is conceptualised. It theorizes multidimensional knowledge updating, search start/stopping criteria, and search/decision heuristics. These components are formulated or empirically modelled and integrated in a unified and coherent approach.
Findings
The theory is supported by empirical observations and the derived quantitative models are tested by an agent-based simulation on a demonstration network.
Originality and value
Based on artificially intelligent agents, learning and search theory, and bounded rationality, this chapter makes an effort to embed a sound theoretical foundation for the computational process approach and agent-based microsimulations. A pertinent new theory is proposed with experimental observations and estimations to demonstrate agents with systematic deviations from the rationality paradigm. Procedural and multidimensional decision-making are modelled. The numerical experiment highlights the capabilities of the proposed theory in estimating rich behavioural dynamics.
Details
Keywords
This paper aims to study the residual stress of deposited components which is a main issue to impede the widespread application of wire and arc additive manufacturing (WAAM). The…
Abstract
Purpose
This paper aims to study the residual stress of deposited components which is a main issue to impede the widespread application of wire and arc additive manufacturing (WAAM). The interlayer dwell time is believed to have an effect on residual stress distributions in WAAM due to variance in heat dissipation condition. A coupled thermomechanical finite element model was established to evaluate the role of dwell time in between layers on the mechanical behavior of thin-walled components in WAAM, mainly involving thermal stress evolutions and residual stress distributions of the component and substrate.
Design/methodology/approach
Four interlayer dwell times including 0, 120 and 300 s and cooling to ambient temperature were selected in finite element modeling, and corresponding experiments were conducted to verify the reliability of the model.
Findings
The results show that with the interlayer dwell time, the stress cycling curves become more uniform and the interlayer stress-releasing effect is weakened. The residual stress levels on the substrate decrease with the increasing interlayer dwell time. In the outside surface of the component, the distributions of axial and longitudinal residual stress along the deposition path are the smoothest when the interlayer dwell time is cooling to ambient temperature. In the inside surface, a longer interlayer dwell time leads to an obvious decrease in the longitudinal and axial residual stress along the deposition path.
Originality/value
The comprehensive study of how the interlayer dwell time influences stress field of components is helpful to improve the deposition defects generated by WAAM.
Details
Keywords
Janmejay Dattatraya Kulkarni, Suresh Babu Goka, Pradeep Kumar Parchuri, Hajime Yamamoto, Kazuhiro Ito and Suryakumar Simhambhatla
The use of a gas metal arc welding-based weld-deposition, referred to as wire-direct energy deposition or wire-arc additive manufacturing, is one of the notable additive…
Abstract
Purpose
The use of a gas metal arc welding-based weld-deposition, referred to as wire-direct energy deposition or wire-arc additive manufacturing, is one of the notable additive manufacturing methods for producing metallic components at high deposition rates. In this method, the near-net shape is manufactured through layer-by-layer weld-deposition on a substrate. However, as a result of this sequential weld-deposition, different layers are subjected to different types of thermal cycles and partial re-melting. The resulting microstructural evolution of the material may not be uniform. Hence, the purpose of this study is to assess microstructure variation along with the lamination direction (or build direction).
Design/methodology/approach
The study was carried out for two different boundary conditions, namely, isolated condition and cooled condition. The microstructural evolution across the layers is hypothesized based on experimental assessment; this included microhardness, scanning electron microscopy imaging and electron backscatter diffraction analysis. These conditions subsequently collaborated with the help of thermal modeling of the process.
Findings
During a new layer deposition, the previous layer also is subject to re-melt. While the newly added layer undergoes rapid cooling through a combination of convection, conduction and radiation losses, the penultimate layer, sees a slower cooling curve due to its smaller exposure area. This behavior of rapid-solidification and subsequent re-melting and re-solidification is a progressing phenomenon across the layers and the bulk of the layers have uniform grains due to this remelt-re-solidification phenomenon.
Research limitations/implications
This paper studies the microstructure variation along with the build direction for thin-walled components fabricated through weld-deposition. This study would be helpful in addressing the issue of anisotropy resulting from the distinctive thermal history of each layer in the overall theme of metal additive manufacturing.
Originality/value
The unique aspect of this paper is the postulation of a generic hypothesis, based on experimental findings and supported by thermal modeling of the process, for remelt-re-solidification phenomenon followed by temperature raising/lowering repetitively in every layer deposition across the layers. This is implemented for different types of base plate conditions, revealing the role of boundary conditions on the microstructure evolution.
Details
Keywords
This paper aims to introduce a novel concept of a double-wire feed (DWF) to alleviate heat accumulation and improve the cooling rate of the molten pool in gas tungsten arc…
Abstract
Purpose
This paper aims to introduce a novel concept of a double-wire feed (DWF) to alleviate heat accumulation and improve the cooling rate of the molten pool in gas tungsten arc (GTA)-based additive manufacturing (AM), in which the former wire is fed into the arc and the latter wire is melt by the molten pool.
Design/methodology/approach
The microstructure, phase composition and mechanical properties of 308 L stainless steel components built by single-wire feed (SWF) AM and DWF-AM are compared, and the differences are analyzed in detail.
Findings
The microstructures for both wire feeding modes include δ and γ phases. Compared with the SWF-AM, the sample fabricated in the DWF-AM exhibits finer microstructure, and the microstructure in the middle region is transformed from columnar grains to cellular grains. Microhardness of the sample produced in the DWF-AM is higher than the SWF-AM. In comparison to the SWF-AM, the tensile strength of the specimen fabricated using the DWF-AM reaches 571 MPa and increases by 16.14%.
Originality/value
This study proposes a novel concept of the DWF-AM to reduce heat accumulation as well as enhance the cooling rate of the molten pool, and improved mechanical properties of the 308 L stainless steel component are obtained.
Details
Keywords
Ming K. Lim, Weiqing Xiong and Chao Wang
In the last decade, cloud manufacturing (CMfg) has attracted considerable attention from academia and industry worldwide. It is widely accepted that the design and analysis of…
Abstract
Purpose
In the last decade, cloud manufacturing (CMfg) has attracted considerable attention from academia and industry worldwide. It is widely accepted that the design and analysis of cloud manufacturing architecture (CMfg-A) are the basis for developing and applying CMfg systems. However, in existing studies, analysis of the status, development process and internal characteristics of CMfg-A is lacking, hindering an understanding of the research hotspots and development trends of CMfg-A. Meanwhile, effective guidance is lacking on the construction of superior CMfg-As. The purpose of this paper is to review the relevant research on CMfg-A via identification of the main layers, elements, relationships, structure and functions of CMfg-A to provide valuable information to scholars and practitioners for further research on key CMfg-A technologies and the construction of CMfg systems with superior performance.
Design/methodology/approach
This study systematically reviews the relevant research on CMfg-A across transformation process to internal characteristics by integrating quantitative and qualitative methods. First, the split and reorganization method is used to recognize the main layers of CMfg-A. Then, the transformation process of six main layers is analysed through retrospective analysis, and the similarities and differences in CMfg-A are obtained. Subsequently, based on systematic theory, the elements, relationships, structure and functions of CMfg-A are inductively studied. A 3D printing architecture design case is conducted to discuss the weakness of the previous architecture and demonstrate how to improve it. Finally, the primary current trends and future opportunities are presented.
Findings
By analyzing the transformation process of CMfg-A, this study finds that CMfg-A resources are developing from tangible resources into intangible resources and intelligent resources. CMfg-A technology is developing from traditional cloud computing-based technology towards advanced manufacturing technology, and CMfg-A application scope is gradually expanding from traditional manufacturing industry to emerging manufacturing industry. In addition, by analyzing the elements, relationships, structure and functions of CMfg-A, this study finds that CMfg-A is undergoing a new generation of transformation, with trends of integrated development, intelligent development, innovative development and green development. Case study shows that the analysis of the development trend and internal characteristics of the architecture facilitates the design of a more effective architecture.
Research limitations/implications
This paper predominantly focuses on journal articles and some key conference papers published in English and Chinese. The reason for considering Chinese articles is that CMfg was proposed by the Chinese and a lot of Chinese CMfg-A articles have been published in recent years. CMfg is suitable for the development of China’s manufacturing industry because of China’s intelligent manufacturing environment. It is believed that this research has reached a reliable comprehensiveness that can help scholars and practitioners establish new research directions and evaluate their work in CMfg-A.
Originality/value
Prior studies ignore the identification and analysis of development process and internal characteristics for the current development of CMfg-A, including the main layers identification of different CMfg-As and the transformation process analysis of these main layers, and in-depth analysis of the inner essence of CMfg-A (such as its elements, relationships, structure and functions). This study addresses these limitations and provides a comprehensive literature review.
Details
Keywords
Chunming Zhang and Xiaoping Zhang
Inkjet printing is becoming increasingly important and popular for the printing of textiles. As one of the environmentally friendly processes, the plasma has been widely used to…
Abstract
Purpose
Inkjet printing is becoming increasingly important and popular for the printing of textiles. As one of the environmentally friendly processes, the plasma has been widely used to modify the surface properties of inkjet printing substrates. The purpose of this paper is to investigate the nano-modification of plasma on polyester fabric for pigment inkjet printing. The actual printing performance and the related mechanical behavior of samples were also evaluated.
Design/methodology/approach
Polyester fabrics were surface modified by atmospheric pressure air plasma with the aim to improve its inkjet printing performance. The effects of plasma treatment on surface properties of fabrics were characterized using X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM). The wettability of the samples is evaluated by measurement of contact angles of different polar liquids and surface energy. Breaking strength and elongation, bending rigidity are tested to evaluate the mechanical behavior of treated and control fabrics.
Findings
It was found that the nano-modification of plasma markedly improved the anti-bleeding property of inkjet printing fabrics. SEM and XPS analyses indicated that this improved color performance was mainly contributed by not only the etching effect and oxygen containing polar groups induced onto fiber surfaces. In addition, the results of mechanical behavior test indicate no evident reduction of breaking strength and breaking elongation both in warp and weft direction after plasma modification.
Originality/value
The surface modification method used here offers an economic and dependable way for pretreatment of inkjet printing fabrics with the advantages of environmental friendly over traditional pretreatment methods.
Details
Keywords
An accurate prediction of process-induced residual stress is necessary to prevent large distortion and cracks in gas metal arc (GMA)-based additive manufactured parts, especially…
Abstract
Purpose
An accurate prediction of process-induced residual stress is necessary to prevent large distortion and cracks in gas metal arc (GMA)-based additive manufactured parts, especially thin-walled parts. The purpose of this study is to present an investigation into predicting the residual stress distributions of a thin-walled component with geometrical features.
Design/methodology/approach
A coupled thermo-mechanical finite element model considering a general Goldak double ellipsoidal heat source is built for a thin-walled component with geometrical features. To confirm the accuracy of the model, corresponding experiments are performed using a positional deposition method in which the torch is tilted from the normal direction of the substrate. During the experiment, the thermal cycle curves of locations on the substrate are obtained by thermocouples. The residual stresses on the substrate and part are measured using X-ray diffraction. The validated model is used to investigate the thermal stress evolution and residual stress distributions of the substrate and part.
Findings
Decent agreements are achieved after comparing the experimental and simulated results. It is shown that the geometrical feature of the part gives rise to an asymmetrical transversal residual stress distribution on the substrate surface, while it has a minimal influence on the longitudinal residual stress distribution. The residual stress distributions of the part are spatially uneven. The longitudinal tensile residual stress is the prominent residual stress in the central area of the component. Large wall-growth tensile residual stresses, which may cause delamination, appear at both ends of the component and the substrate–component interfaces.
Originality/value
The predicted residual stress distributions of the thin-walled part with geometrical features are helpful to understand the influence of geometry on the thermo-mechanical behavior in GMA-based additive manufacturing.