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Analytic Model Predictive Current Control of Grid-Connected Power Conversion System in Battery Energy Storage System

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IEEE TRANSACTIONS ON POWER ELECTRONICS 2025年第3期40卷 3952-3967页

作者： Zhang, Mingming Li, Mian Zhang, Jun Shanghai Jiao Tong Univ Global Inst Future Technol Shanghai 200240 Peoples R China Shanghai Jiao Tong Univ UMich SJTU Joint Inst Shanghai 200240 Peoples R China

In this article, an analytic model predictive current controller is proposed for the grid-connected power conversion system (PCS) in the battery energy storage system (BESS). This controller is designed to provide the fast and robust dynamic response while maintaining the moderate computational cost, making it suitable for real-time industrial microcontrollers. An accurate discrete-time model of the grid-connected PCS is derived to enable a closed-form solution, and the 3-D current reference tracking problem, incorporating the varying dc-link voltage of the BESS, is formulated as a multiparametric quadratic program. For this optimization problem, the constrained optimal control law is shown to be the accurate orthogonal projection of the unconstrained solution onto the corresponding active voltage constraint. Subsequently, an efficient geometric method is developed to obtain the analytic optimal control in the general case, enabling the online application of MPC with a long prediction horizon for industrial PCS. Moreover, a disturbance observer is combined with the predictive current controller to ensure offset-free tracking and robustness against system uncertainties. Simulation and experimental results on a 20 kVA PCS demonstrate the fast dynamics, low total harmonic distortion, strong robustness, and high computational efficiency of the proposed current controller.

关键词： Voltage control Predictive models computational modeling Analytical models Matrix converters Battery energy storage system Switches Optimal control Accuracy Robustness Analytic model predictive current controller (APCC) grid-connected battery energy storage system (BESS) high computational efficiency long prediction horizon power conversion system (PCS)

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A Fast Complementary Filter for Avoiding the Magnetometer Measurements From Influencing the Calculation of Pitch and Roll

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IEEE SENSORS JOURNAL 2025年第7期25卷 11521-11531页

作者： Rong, Hailong Peng, Cuiyun Chen, Yang Lv, Jidong Zhu, Yanping Zou, Ling Changzhou Univ Sch Mech Engn & Rail Transit Changzhou 213164 Peoples R China Changzhou Univ Sch Wangzheng Microelect Changzhou 213159 Peoples R China

Despite the magnetometer in a magnetic and inertial measurement unit (MIMU) being used to estimate the azimuth, its measurements can also negatively affect the computation of inclination angles when magnetic disturbance appears. It is challenging to eliminate that negative effect. For problem-solving, a new complementary filter (CF) is proposed. The filter is divided into two stages. In the first stage, the attitude represented by quaternion is predicted by gyroscope, and then, the predicted quaternion is converted to Euler angles. In the second stage, the predicted Euler angles are compensated by employing the accelerometer and the magnetometer, and then, the after-compensated Euler angles are converted back to quaternion. To solve the problem of "gimbal lock," two sets of Euler angles with different definitions of the rotation sequence are used. The simulation and experiment results demonstrate that the proposed filter outperforms six other competing filters, revealing its potential usage in such applications where magnetic disturbance is not allowed to affect the computation of inclination angles.

关键词： Magnetic separation Magnetometers Mathematical models Accelerometers Quaternions Pollution measurement Azimuth Position measurement Gyroscopes Vectors Attitude and heading reference system complementary filter (CF) Euler angles high computational efficiency magnetic disturbance

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Protein Residue Contact Prediction Based on Deep Learning and Massive Statistical Features from Multi-Sequence Alignment

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Tsinghua Science and Technology 2022年第5期27卷 843-854页

作者： Huiling Zhang Min Hao Hao Wu Hing-Fung Ting Yihong Tang Wenhui Xi Yanjie Wei Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China College of Electronic and Information Engineering Southwest UniversityChongqing 400715China School of Software Engineering University of Science and Technology of ChinaHefei 230051China Department of Computer Science The University of Hong KongHong Kong 999077China School of Computer Science Beijing University of Posts and TelecommunicationsBeijing 100876China

Sequence-based protein tertiary structure prediction is of fundamental importance because the function of a protein ultimately depends on its 3 D *** accurate residue-residue contact map is one of the essential elements for current ab initio prediction protocols of 3 D structure ***,with the combination of deep learning and direct coupling techniques,the performance of residue contact prediction has achieved significant ***,a considerable number of current Deep-Learning(DL)-based prediction methods are usually time-consuming,mainly because they rely on different categories of data types and third-party *** this research,we transformed the complex biological problem into a pure computational problem through statistics and artificial *** have accordingly proposed a feature extraction method to obtain various categories of statistical information from only the multi-sequence alignment,followed by training a DL model for residue-residue contact prediction based on the massive statistical *** proposed method is robust in terms of different test sets,showed high reliability on model confidence score,could obtain high computational efficiency and achieve comparable prediction precisions with DL methods that relying on multi-source inputs.

关键词： multi-sequence alignment residue-residue contact prediction feature extraction statistical information Deep Learning(DL) high computational efficiency

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Constitutive modeling of ultra?fine?grained titanium flow stress for machining temperature prediction

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Bio-Design and Manufacturing 2019年第3期2卷 153-160页

作者： Jinqiang Ning Vinh Nguyen Yong Huang Karl T.Hartwig Steven Y.Liang George W.Woodruff School of Mechanical Engineering Georgia Institute of Technology801 Ferst DriveAtlantaGA 30332USA Department of Mechanical and Aerospace Engineering University of Florida231 MAE-AP.O.Box 116250GainesvilleFL 32611USA Department of Mechanical Engineering Texas A&M University3123 TAMUCollege StationTX 77843?3123USA

This work investigates the machining temperatures of ultra-fine-grained titanium(UFG Ti),prepared by equal channel angular extrusion,through analytical *** Ti has great usefulness in biomedical applications because of its high mechanical strength,sufficient manufacturability,and high *** temperatures were predicted using a physics-based predictive model based on material constitutive relation and mechanics of the orthogonal cutting *** minimization between the stress calculated using Johnson–Cook constitutive model and the same stress calculated using mechanics model yields the estimation of machining temperatures at two deformation *** agreements are observed upon validation to the values reported in the *** machinability of UFG Ti is investigated by comparing its machining temperature to that of Ti–6Al–4V alloy under the same cutting *** lower temperatures are observed in machining UFG *** computational efficiency of the presented model is investigated by comparing its average computational time(~0.5 s)to that of a widely used modified chip formation model(8900 s)with comparable prediction *** work extends the applicability of the presented temperature model to a broader class of materials,specifically ultra-fine-grained *** high computational efficiency allows the in situ temperature prediction and optimization of temperature condition with process parameters planning.

关键词： Ultra-fine-grained titanium Analytical modeling high computational efficiency Johnson–Cook model Cutting mechanics

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Characteristic matching of stochastic scenarios and flexible resource capacity optimisation for isolated microgrids

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IET GENERATION TRANSMISSION & DISTRIBUTION 2020年第24期14卷 6009-6018页

作者： Cen, Bowei Cai, Zexiang Liu, Ping Chen, Yuanju Sun, Yuyan Hu, Kaiqiang Zeng, Xing South China Univ Technol Sch Elect Power Guangzhou 510641 Peoples R China China Southern Power Grid Energy Dev Res Inst Guangzhou Peoples R China

Considering a large number of stochastic scenarios when optimising the flexible resource capacity for isolated microgrids not only improves the accuracy and credibility of the results but also enables the use of probabilistic statistical methods to obtain a scheme that balances robustness and costs. However, the consideration of massive scenarios can drastically lower the computational efficiency, and there is a lack of research on configuration methods that can result in a compromise. In this study, a characteristic-matching method is proposed to enhance the computational efficiency of optimisation, and a statistics-based prism filtering method is designed to obtain the compromise scheme for use by decision-makers. Specifically, the massive scenario set is divided into four subsets. The characteristic-matching method is proposed to obtain a near-optimal solution, which is used as the initial iteration value to accelerate the computational speed. Then, a characteristic-matching-based bi-level optimisation method is proposed to solve massive scenarios with high computational efficiency. Moreover, a prism filtering method is designed to select a compromise scheme with high economic benefits using scenario coverage, load curtailment, power curtailment and economy indicators. Simulation results verify the effectiveness of the proposed models and methods.

关键词： decision making stochastic processes iterative methods distributed power generation optimisation statistical analysis demand side management characteristic matching stochastic scenarios flexible resource capacity optimisation isolated microgrids probabilistic statistical methods configuration methods characteristic-matching method statistics-based prism filtering method compromise scheme massive scenario set computational speed bi-level optimisation method high computational efficiency scenario coverage decision-makers near-optimal solution initial iteration value economic benefits load curtailment power curtailment economy indicators

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Analytical modeling of lack-of-fusion porosity in metal additive manufacturing

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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING 2019年第11期125卷 1-11页

作者： Ning, Jinqiang Wang, Wenjia Zamorano, Bruno Liang, Steven Y. Georgia Inst Technol George W Woodruff Sch Mech Engn 801 Ferst Dr Atlanta GA 30332 USA Boeing Co 499 Boeing Blvd Huntsville AL 35824 USA

This work presents a physics-based analytical modeling methodology for the prediction of the lack-of-fusion porosity in powder bed metal additive manufacturing (PBMAM) considering the molten pool geometry, powder size variation, and packing. The presented model has promising short computational time without resorting to the finite element method or any iteration-based simulations. The temperature profiles were calculated using a closed-form temperature solution. Multiple transverse sectional areas of the molten pool geometry were plotted on a cross-sectional area of the part based on hatch space and layer thickness to calculate the lack-of-fusion area. The powder bed porosity was calculated using advancing front approach with consideration of powder statistical distribution and powder packing. The part porosity was converted from the calculated lack-of-fusion area by multiplying the calculated powder bed porosity. Acceptable agreements were observed upon validation against experimental measurements under various process conditions in PBMAM of Ti6Al4V. The computational time was recorded less than 26 s for the porosity calculation of five consecutive layers. The presented model has high prediction accuracy and high computational efficiency, which allow the porosity calculation for large-scale parts and process parameters planning through inverse analysis, and thus improves the usefulness of analytical modeling in real applications.

关键词： Lack-of-fusion porosity Powder bed metal additive manufacturing Closed-form temperature solution Statistical powder size variation and packing high computational efficiency

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3D deterministic ray tracing method for massive MIMO channel modelling and parameters extraction

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IET COMMUNICATIONS 2020年第18期14卷 3169-3174页

作者： Liu, Gang She, Jun Lu, Wenjun Zhang, Ming Bo, Yaming Nanjing Univ Posts & Telecommun Coll Elect & Opt Engn Nanjing 210003 Peoples R China Nanjing Univ Posts & Telecommun Coll Microelect Nanjing 210003 Peoples R China Nanjing Univ Posts & Telecommun Jiangsu Key Lab Wireless Commun Nanjing 210003 Peoples R China

Geometric stochastic method and deterministic ray tracing method are two common methods of modelling massive multiple-input multiple-output (MIMO) channels. The former has high computational efficiency but a large number of input parameters need to be extracted from measurements for different environments. Conversely, the latter is more suitable for a specific environment but consumes a lot of computing costs. In this study, a novel three-dimensional (3D) deterministic ray tracing method for massive MIMO channel modelling is proposed. The computational efficiency can be improved in two aspects compared with conventional deterministic ray tracing methods. Firstly, substantial intersection tests used in determining the propagation paths of rays are replaced with the adjacency relationships between tetrahedrons. Secondly, the process of ray tracing is independent of the location of a receiving antenna and therefore repeated ray tracing process is unnecessary for different elements of receiving antenna array. The proposed method is also used as a substitute for measurements to extract input parameters for geometric stochastic channel models. The accuracy of the proposed method in massive MIMO channel modelling and parameters extraction is verified by comparing the results with measurements and other existing channel models.

关键词： radiowave propagation receiving antennas ray tracing MIMO communication antenna arrays stochastic processes massive MIMO channel modelling parameters extraction geometric stochastic method massive multiple-input multiple-output channels high computational efficiency input parameters three-dimensional deterministic ray tracing method conventional deterministic ray tracing methods geometric stochastic channel models receiving antenna array

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MaCo: efficient unsupervised low-light image enhancement via illumination-based magnitude control

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VISUAL COMPUTER 2024年第12期40卷 8481-8499页

作者： Shi, Yiqi Liu, Duo Zhang, Liguo Xia, Xuezhi Sun, Jianguo Harbin Engn Univ Sch Comp Sci & Technol Harbin 150006 Heilongjiang Peoples R China Xidian Univ Hangzhou Inst Technol Sch Comp Sci & Technol Hangzhou 311231 Zhejiang Peoples R China

This paper presents a novel low-light image enhancement (LLIE) method based on magnitude control (MaCo). Our method establishes a relationship between the low-light image and illumination, using pixel intensity and image brightness. Exploiting this relationship, MaCo enhances pixels with varying magnitudes, achieving pixel-wise LLIE. This yields high-quality enhanced images without local overexposure. We also introduce a set of carefully formulated unsupervised loss functions to enable training using only low-light images. Concretely, our method first trains a lightweight deep network, Low-res Coefficient Estimation Network (LCE-Net), to estimate the feature map in low-resolution space. Next, the high-res Illumination Estimation Module (HIE Module) is proposed to perform bilateral-grid-based upsampling for obtaining the high-res illumination. The illumination is finally utilized to light up the low-light image, yielding the enhanced image. MaCo is efficient and consumes fewer resources, as most computations occur in low resolution and the network is lightweight. Current LLIE datasets are mostly synthesized or generated through altered camera settings. These datasets are often limited in accurately representing real-world situations. To address this problem, we create a new dataset, IOLD, containing 572 images captured under real low- and normal-light conditions. In particular, the potential advantage of MaCo for face detection in the dark is also discussed. Extensive qualitative and quantitative experiments demonstrate that our method performs favorably against state-of-the-art methods in terms of effectiveness and efficiency. The IOLD dataset will be made publicly available at https://***/drive/folders/1VAkuj9gheZ4aPEhBZ5MszHF6zpbrE_9_?usp=sharing.

关键词： Low-light image enhancement (LLIE) Unsupervised learning Magnitude control high computational efficiency

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An Efficient Disk-Based Discontinuous Deformation Analysis Model for Simulating Large-Scale Problems

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INTERNATIONAL JOURNAL OF GEOMECHANICS 2020年第7期20卷

作者： Huang, Gang-Hai Xu, Yuan-Zhen Yi, Xiong-Wei Xia, Ming Hunan Univ Sci & Technol Hunan Prov Key Lab Geotech Engn Stabil Control & Sch Civil Engn Xiangtan 411201 Peoples R China Hunan Univ Sci & Technol Sch Resource & Environm & Safety Engn Xiangtan 411201 Peoples R China Xiangtan Univ Coll Civil Engn & Mech Xiangtan 411105 Peoples R China

Simulating large-scale problems are still challenging for discontinuous deformation analysis (DDA). To this end, this paper develops an efficient disk-based DDA (DDDA) model considering the efficiency in searching contact pairs and solving linear equations. First, an efficient contact search algorithm, namely the lattice search algorithm (LSA), is proposed, and efficiency tests of the LSA and direct search algorithm (DSA) demonstrate the high efficiency of the LSA. Second, three equations solvers, namely Jacobi iterative method (J), conjugate gradient method (CG), and preconditioned CG (PCG), are adopted to respectively solve the equations of the DDDA, and efficiency tests of these solvers show that the best solver is the PCG and the J is unsuited to solving the equations when using large penalty spring stiffness. Finally, a landslide simulation which includes 30,000 disks, 5,990 line segments, and 180,000 calculation steps is conducted, the result of which shows that: (1) up to 41.1 h, which is 99.2% of the time consumed in contact search using the DSA, is reduced by using the LSA;(2) up to 18.22 h, which is 69.8% of the time consumed in solving the equations using the CG, is reduced by using the PCG as the equation solver;(3) the time consumed in the simulation is 68.72 h when using the DSA to search contact pairs and using the CG to solve the equations;while the consumed time reduces to 9.4 h when using the LSA to search contact pairs and using the PCG to solve the equations, whose reduction proportion is 86.3%. The simulation indicates the large-scale computation capacity and further application in engineering with the DDDA.

关键词： Disk-based discontinuous deformation analysis Lattice search algorithm Equations solver high computational efficiency Large-scale problem

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Calculation of AC resistance of single-layer coils using boundary-element method

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IET ELECTRIC POWER APPLICATIONS 2021年第1期15卷 1-12页

作者： Luo, Yao Theodoulidis, Theodoros Zhou, Xinglong Kyrgiazoglou, Athanasios Wuhan Univ Sch Elect Engn & Automat Wuhan Peoples R China Univ Western Macedonia Dept Mech Engn Kozani Greece State Grid Shanghai Municipal Elect Power Co Shanghai Peoples R China

Boundary-element method (BEM) is applied to the analysis of AC resistance of single-layer coils. For simplification of the analysis, the coil windings are replaced by a system of parallel straight conductors. Applying the method of images and closed-form solutions of off-diagonal matrix elements, and exploiting the symmetry of submatrices, high computational efficiency can be achieved by the proposed approach. As a numerical method, it is suitable for solenoids or pancake coils evenly wound by round or rectangular wires, or other wire shapes with proper symmetry. The proposed method is verified by the numerical results compared with those of finite-element method (FEM) and measurements, from which it is confirmed that the proposed approach has the same accuracy as the FEM, and the former is much faster and more memory efficient.

关键词： coil windings Finite element analysis pancake coils parallel straight conductors Conductors solenoids single-layer coils matrix algebra conductors (electric) high computational efficiency finite-element method Linear algebra (numerical analysis) off-diagonal matrix elements coils AC resistance boundary-element method closed-form solutions numerical method Inductors and transformers finite element analysis boundary-elements methods

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