Article
Thermodynamics
Prateek Singh, Manoj Kumar Sharma, Manmeet Singh, Jishnu Bhattacharya
Summary: A parabolic trough collector is widely used for concentrated solar heat collection, and its performance is affected by the deviations between the actual optical setup and ideal mathematical model. This study investigates the relative importance of different irregularities and suggests focusing on critical ones within an acceptable cost threshold. The tested irregularities include absorber tube misalignment, random profile error, narrowed and widened reflector profile, and tracking error. Results show that a tracking error up to 10 mrad has minimal performance loss, while misalignment error and narrowing of reflector profile not only cause heat interception loss but also damage to the absorber tube coating and cover system. Simultaneous occurrence of multiple irregularities can lead to a significant performance loss (around 50% in this study), requiring intervention and remediation.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Jian Yan, YouDuo Peng, YongXiang Liu
Summary: This paper evaluates the optical performance of solar dish/Stirling power systems under wind load. By simulating wind conditions, the structural deformation, mirror slope error, and flux distribution of the system are analyzed, and the causes and manifestations of optical deterioration are identified.
Article
Computer Science, Information Systems
Husna Mutahira, Bilal Ahmad, Mannan Saeed Muhammad, Dong Ryeol Shin
Summary: A method for directly processing colored images to measure focus is proposed, which shows the highest correlation and smallest RMSE values in shape recovery.
Article
Optics
Jiankun Sun, Zhihui Yang, Fanfei Li, Qun Hao, Shaohui Zhang
Summary: Fringe projection profilometry is a widely used technique for high-precision 3D measurement. However, existing point cloud registration methods often have limitations in terms of cost or application scope. To address this, we propose a low-cost and feasible method that combines active projection textures, color channel multiplexing, image feature matching, and coarse-to-fine point registration strategies. Experimental results demonstrate its effectiveness for large-size and weak-textured objects.
Article
Thermodynamics
Yan Jian, You Duo Peng, Yong Xiang Liu
Summary: This paper proposes an optical-mechanical integrated modeling method to evaluate the optical performance and flux distribution of SDC system under service load. The method combines the finite element method and ray-tracing method to directly establish the optical model considering the mirror deformation, suitable for various concentrators.
Article
Automation & Control Systems
Rami Katz, Emilia Fridman
Summary: This paper proposes a sampled-data implementation of a finite-dimensional boundary controller for 1D parabolic PDEs under discrete-time point measurement. By employing dynamic extension and proportional-integral controller, the controller is implemented through a generalized hold device. The quantization effect and input-to-state stability analysis are considered. The paper also introduces a new form of Halanay's inequality for ISS to compensate for sampling in the infinite-dimensional tail.
Article
Green & Sustainable Science & Technology
Shuaishuai Liu, Bin Yang, Yuan Zhi, Xiaohui Yu
Summary: The thermal-mechanical performance of the parabolic trough receiver is analyzed using the combined MCRT-FVM-FEM approach, focusing on the effects of optical errors. The deformation and stress of bellows and Kovar rings under multi-error conditions are investigated, and it is found that optical errors mainly affect the axial stress of the bellows and Kovar rings.
Article
Engineering, Multidisciplinary
Noby George, Prashanth Vooka, A. Sai Kartheek Bandi, S. Gopalakrishna
Summary: A new high precision conversion technique is introduced in this paper, which directly provides digital outputs of Ratio Error and Phase Errors of an Instrument Transformer under test. Additionally, a novel method to improve measurement accuracy is proposed by comparing a test IT with a standard IT.
Article
Engineering, Electrical & Electronic
Shuaichen Ye, Xiaoxian Yao
Summary: This article presents an enhanced sliding-mode observer (SMO) for speed and position estimation in a sensorless drive scheme for permanent-magnet synchronous machine (PMSM) with current measurement error compensators. The effectiveness of the enhanced SMO and current compensators is validated by comparative experiments, showing satisfactory chatter reduction and current ripple suppression performance of the proposed method. The integration of current compensators into the enhanced SMO enables the construction of a practical PMSM sensorless field-oriented control (FOC) scheme.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Engineering, Multidisciplinary
Ruibin He, Hongfang Chen, Bailin Liu, Yanqiang Sun, Huixu Song, Zhaoyao Shi
Summary: In this study, an improved variable universe fuzzy proportional-integral (PI) control method is proposed, which achieves fast response, high steady-state accuracy, and strong anti-interference performance through feedback compensation. Experimental results show that the proposed method outperforms the conventional PI control method in the forward and reverse speed regulation processes of the motor.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Thermodynamics
Jian Yan, YouDuo Peng, YongXiang Liu
Summary: In this study, an optical-mechanical integration model was established to evaluate the effects of self-weight on the optical performance of a 38 kW dish/Stirling system. The results showed that the mirror slope error increased with the increase of elevation angle when only the concentrator was deformed, and the mirror slope error increased with its deformation, but their distribution laws were different. The XEM-Dish system maintained an excellent optical efficiency of 87% and flux distribution under self-weight load, with SDx around 0.58 mrad at 0 degrees-60 degrees elevation angle.
Article
Mathematics, Interdisciplinary Applications
Liu Yaqiang, Ren Zhigang, Jin Zengwang
Summary: This paper investigates a robust H infinity control problem of a class of linear parabolic distributed parameter systems using the robust H infinity feedback compensator design approach. A sufficient condition for the exponential stability of the corresponding closed-loop coupled system under an H infinity performance constraint is presented, utilizing Lyapunov technique, mathematical inequalities, and integration theory.
Article
Dermatology
Qiuying Chen, Dalee Zhou, Zalfa Abdel-Malek, Fengli Zhang, Philip S. Goff, Elena Sviderskaya, Kazumasa Wakamatsu, Shosuke Ito, Steven S. Gross, Jonathan H. Zippin
Summary: A new method was developed to actively measure the synthesis of both eumelanin and pheomelanin using liquid chromatography-mass spectrometry, shedding new light on melanin synthesis and revealing new insights into the mechanisms of melanogenesis.
JOURNAL OF INVESTIGATIVE DERMATOLOGY
(2021)
Article
Engineering, Multidisciplinary
Sangmin Lee, Kibok Lee
Summary: This paper proposes a PI-type observer-based current offset error compensation method for the induction motor, which can estimate the DC offset error during motor operation. The study analyzes the effect of parameter mismatch and confirms the robustness of the system. Simulation and experimental results are provided to verify the performance of the proposed method.
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS
(2023)
Article
Computer Science, Artificial Intelligence
Zi-Peng Wang, Huai-Ning Wu, Mohammed Chadli
Summary: This article explores the design of H-infinity SDFO for nonlinear PDE systems under SLAMs, using T-S fuzzy PDE model and linear matrix inequalities. The method is validated through simulations on state estimation of the FitzHugh-Nagumo equation.
IEEE TRANSACTIONS ON FUZZY SYSTEMS
(2021)
Article
Energy & Fuels
W. Reinalter, S. Ulmer, P. Heller, T. Rauch, J. -M. Gineste, A. Ferriere, F. Nepveu
JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME
(2008)
Article
Energy & Fuels
M. Roeb, J. -P. Saeck, P. Rietbrock, C. Prahl, H. Schreiber, M. Neises, L. de Oliveira, D. Graf, M. Ebert, W. Reinalter, M. Meyer-Gruenefeldt, C. Sattler, A. Lopez, A. Vidal, A. Elsberg, P. Stobbe, D. Jones, A. Steele, S. Lorentzou, C. Pagkoura, A. Zygogianni, C. Agrafiotis, A. G. Konstandopoulos
Article
Energy & Fuels
Steffen Ulmer, Tobias Maerz, Christoph Prahl, Wolfgang Reinalter, Boris Belhomme
Proceedings Paper
Green & Sustainable Science & Technology
Javier Leon, Javier Clavero, Loreto Valenzuela, Eduardo Zarza, Christoph Hilgert, Wolfgang Reinalter, Andreas Plumpe
INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS (SOLARPACES 2017)
(2018)
Proceedings Paper
Energy & Fuels
M. Ebert, W. Arnold, A. Avila-Marin, T. Denk, J. Hertel, A. Jensch, W. Reinalter, A. Schlierbach, R. Uhlig
INTERNATIONAL CONFERENCE ON CONCENTRATING SOLAR POWER AND CHEMICAL ENERGY SYSTEMS, SOLARPACES 2014
(2015)
Article
Energy & Fuels
S Ulmer, W Reinalter, P Heller, E Lupfert, D Martínez
JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME
(2002)