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并网变换器虚拟同步无模型参数鲁棒增强控制策略

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电力系统保护与控制 2024年第7期52卷 80-88页

作者：王天宇赵晋斌潘超毛玲上海电力大学电气工程学院上海200090 上海电力大学海上风电研究院上海200090

随着新型电力系统的发展,并网变换器已成为能量传输的关键设备。模型预测控制的虚拟同步机参数鲁棒性较低,当并网参数失配时,输出电流纹波增大,同步机功率支撑下降。针对此问题,提出一种改进的虚拟同步无模型参数鲁棒预测控制方法。首先... 详细信息

随着新型电力系统的发展,并网变换器已成为能量传输的关键设备。模型预测控制的虚拟同步机参数鲁棒性较低,当并网参数失配时,输出电流纹波增大,同步机功率支撑下降。针对此问题,提出一种改进的虚拟同步无模型参数鲁棒预测控制方法。首先,该方法采用四阶runge-kutta优化超局部无模型得到虚拟同步机参数增强鲁棒模型。然后,采用Lagrange插值法求解模型中K参数,通过前4个时刻的采样值预测下一时刻的输出。同时设计虚拟惯量无模型自适应预测算法,实现了惯量动态需求响应。最后,经过价值函数寻优比较得到虚拟同步机的优化电压矢量,实现参数鲁棒增强控制。实验结果表明,所提出的控制策略在参数失配情况下功率支撑能力稳定,频率波动时虚拟惯量能够动态响应,具有良好的稳态和动态响应性能。

关键词：并网变换器无模型预测控制参数失配 runge-kutta

B-Theory of runge-kutta methods for stiff Volterra functional differential equations

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Science China Mathematics 2003年第5期46卷 662-674页

作者：李寿佛 Department of Mathematics Xiangtan University Xiangtan 411105 China

B-stability and B-convergence theories of runge-kutta methods for nonlinear stiff Volterra func-tional differential equations (VFDEs) are established which provide unified theoretical foundation for the studyof runge-kutta methods when applied to nonlinear stiff initial value problems (IVPs) in ordinary differentialequations (ODEs), delay differential equations (DDEs), integro-differential equations (IDEs) and VFDEs ofother type which appear in practice.

关键词： stiff functional differential equations, runge-kutta methods, B-stability, B-con-vergence.

Algebraic dynamics algorithm:Numerical comparison with runge-kutta algorithm and symplectic geometric algorithm

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Science China(Physics,Mechanics & Astronomy) 2007年第1期50卷 53-69页

作者： WANG ShunJin ZHANG Hua Center of Theoretical Physics Sichuan UniversityChengdu 610064China

Based on the exact analytical solution of ordinary differential equations, a truncation of the Taylor series of the exact solution to the Nth order leads to the Nth order algebraic dynamics algorithm. A detailed numerical comparison is presented with runge-kutta algorithm and symplectic geometric algorithm for 12 test models. The results show that the algebraic dynamics algorithm can better preserve both geometrical and dynamical fidelity of a dynamical system at a controllable precision, and it can solve the problem of algorithm-induced dissipation for the runge-kutta algorithm and the problem of algorithm-induced phase shift for the symplectic geometric algorithm.

关键词： algebraic dynamics algorithm for ordinary differential equations preserving both geometrical and dynamical fidelity numerical comparison with runge-kutta algorithm and symplectic geometric algorithm

Symplectic partitioned runge-kutta method based onthe eighth-order nearly analytic discrete operator and its wavefield simulations

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Applied Geophysics 2014年第1期11卷 89-106,117,118页

作者：张朝元马啸杨磊宋国杰大理学院数学与计算机学院大理671003 清华大学数学科学系北京100084 西南石油大学理学院成都610500 清华大学计算机系北京100084

We propose a symplectic partitioned runge-kutta （SPRK） method with eighth-order spatial accuracy based on the extended Hamiltonian system of the acoustic waveequation. Known as the eighth-order NSPRK method, this technique uses an eighth-orderaccurate nearly analytic discrete （NAD） operator to discretize high-order spatial differentialoperators and employs a second-order SPRK method to discretize temporal derivatives.The stability criteria and numerical dispersion relations of the eighth-order NSPRK methodare given by a semi-analytical method and are tested by numerical experiments. We alsoshow the differences of the numerical dispersions between the eighth-order NSPRK methodand conventional numerical methods such as the fourth-order NSPRK method, the eighth-order Lax-Wendroff correction （LWC） method and the eighth-order staggered-grid （SG）method. The result shows that the ability of the eighth-order NSPRK method to suppress thenumerical dispersion is obviously superior to that of the conventional numerical methods. Inthe same computational environment, to eliminate visible numerical dispersions, the eighth-order NSPRK is approximately 2.5 times faster than the fourth-order NSPRK and 3.4 timesfaster than the fourth-order SPRK, and the memory requirement is only approximately47.17% of the fourth-order NSPRK method and 49.41% of the fourth-order SPRK method,which indicates the highest computational efficiency. Modeling examples for the two-layermodels such as the heterogeneous and Marmousi models show that the wavefields generatedby the eighth-order NSPRK method are very clear with no visible numerical dispersion.These numerical experiments illustrate that the eighth-order NSPRK method can effectivelysuppress numerical dispersion when coarse grids are adopted. Therefore, this methodcan greatly decrease computer memory requirement and accelerate the forward modelingproductivity. In general, the eighth-order NSPRK method has tremendous potential value forseismic exploration and seismology research.

关键词： Symplectic partitioned runge-kutta method Nearly analytic discrete operator Numerical dispersion Wavefield simulation

Stability analysis of runge-kutta methods for nonlinear neutral delay integro-differential equations

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Science China Mathematics 2007年第4期50卷 464-474页

作者： Yue-xin YU Shou-fu LI Department of Mathematics Xiangtan UniversityXiangtan 411105China

The sufficient conditions for the stability and asymptotic stability of runge-kutta methods for nonlinear neutral delay integro-differential equations are derived. A numerical test that confirms the theoretical result... 详细信息

关键词： neutral delay integro-differential equations runge-kutta methods stability asymptotic stability

runge-kutta Multi-resolution Time-Domain Method for Modeling 3D Dielectric Curved Objects

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Transactions of Nanjing University of Aeronautics and Astronautics 2014年第4期31卷 440-444页

作者：朱敏曹群生赵磊王毅 College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Nanjing ASSEN Environment Technology Co.Ltd.

A conformal runge-kutta multi-resolution time-domain(C-RKMRTD)method is present and applied to model and analyze curved objects.Compared with the non-conformal method,the proposed method is more accurate.The scattering analyses of the cylinder and ellipsoid are presented to validate the proposed method.The numerical results demonstrate that the proposed scheme perform better than the MRTD method and other higher order methods with a higher accuracy.

关键词： conformality runge-kutta multi-resolution time-domain(MRTD) scattering

基于runge-kutta的NURBS曲线实时前瞻插补算法

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华南理工大学学报（自然科学版） 2017年第10期45卷 121-128页

作者：吴玉香王鹏华南理工大学自动化科学与工程学院广东广州510640

针对传统的NURBS曲线加工过程中插补算法插补参数计算精度低、实时性不高以及加速度过大对机床造成的冲击大的问题,提出了基于runge-kutta的NURBS曲线实时前瞻插补算法.该算法采用经典runge-kutta方法计算插补参数,基于弓高误差和法向... 详细信息

针对传统的NURBS曲线加工过程中插补算法插补参数计算精度低、实时性不高以及加速度过大对机床造成的冲击大的问题,提出了基于runge-kutta的NURBS曲线实时前瞻插补算法.该算法采用经典runge-kutta方法计算插补参数,基于弓高误差和法向加速度约束条件自动调整进给速度,根据进给步长预期值与实际值的偏差进行参数校正.由粗插补得到的离线数据寻找进给速度极值点,并对曲线进行前瞻分段,找到各前瞻插补区间上的首末速度敏感点.根据敏感速度与插补距离之间的关系重新进行加减速控制,避免速度急剧变化,从而满足机床的加减速性能要求.最后,通过Matlab仿真验证了算法的有效性.

关键词：数控系统 NURBS曲线 runge-kutta 前瞻插补算法

Mathematical modeling of malaria transmission dynamics in humans with mobility and control states

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Infectious Disease Modelling 2023年第4期8卷 1015-1031页

作者： Gbenga Adegbite Sunday Edeki Itunuoluwa Isewon Jerry Emmanuel Titilope Dokunmu Solomon Rotimi Jelili Oyelade Ezekiel Adebiyi Covenant University Bioinformatics Research Covenant UniversityOtaNigeria Department of Computer and Information Sciences Covenant UniversityOtaNigeria Department of Mathematics Covenant UniversityOtaNigeria Department of Biochemistry Covenant UniversityOtaNigeria Covenant Applied Informatics and Communications-African Centre of Excellence Covenant UniversityOtaOgun StateNigeria Division of Applied Bioinformatics German Cancer Research Center(DKFZ)HeidelbergGermany

Malaria importation is one of the hypothetical drivers of malaria transmission dynamics across the globe.Several studies on malaria importation focused on the effect of the use of conventional malaria control strategies as approved by the World Health Organization(WHO)on malaria transmission dynamics but did not capture the effect of the use of traditional malaria control strategies by vigilant humans.In order to handle the aforementioned situation,a novel system of Ordinary Differential Equations(ODEs)was developed comprising the human and the malaria vector compartments.Analysis of the system was carried out to assess its quantitative properties.The novel computational algorithm used to solve the developed system of ODEs was implemented and benchmarked with the existing runge-kutta numerical solution method.Furthermore,simulations of different vigilant conditions useful to control malaria were carried out.The novel system of malaria models was well-posed and epidemiologically meaningful based on its quantitative properties.The novel algorithm performed relatively better in terms of model simulation accuracy than runge-kutta.At the best model-fit condition of 98%vigilance to the use of conventional and traditional malaria control strategies,this study revealed that malaria importation has a persistent impact on malaria transmission dynamics.In lieu of this,this study opined that total vigilance to the use of the WHO-approved and traditional malaria management tools would be the most effective control strategy against malaria importation.

关键词： Malaria importation Traditional malaria control Ordinary differential equation Quantitative properties Novel algorithm runge-kutta

Numerical Computational Heuristic Through Morlet Wavelet Neural Network for Solving the Dynamics of Nonlinear SITR COVID-19

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Computer Modeling in Engineering & Sciences 2022年第5期131卷 763-785页

作者： Zulqurnain Sabir Abeer S.Alnahdi Mdi Begum Jeelani Mohamed A.Abdelkawy Muhammad Asif Zahoor Raja Dumitru Baleanu Muhammad Mubashar Hussain Department of Mathematics Hazara UniversityMansehraPakistan Department of Mathematics and Statistics Faculty of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)RiyadhSaudi Arabia Department of Mathematics Faculty of ScienceBeni-Suef UniversityBeni-SuefEgypt Future Technology Research Center National Yunlin University of Science and TechnologyYunlinTaiwan Department of Mathematics Cankaya UniversityAnkaraTurkey Institute of Space Sciences Magurele-BucharestRomania Department of Mathematics University of PunjabJhelum CampusJhelumPakistan

The present investigations are associated with designing Morlet wavelet neural network(MWNN)for solving a class of susceptible,infected,treatment and recovered(SITR)fractal systems of COVID-19 propagation and control.The structure of an error function is accessible using the SITR differential form and its initial conditions.The optimization is performed using the MWNN together with the global as well as local search heuristics of genetic algorithm(GA)and active-set algorithm(ASA),i.e.,MWNN-GA-ASA.The detail of each class of the SITR nonlinear COVID-19 system is also discussed.The obtained outcomes of the SITR system are compared with the runge-kutta results to check the perfection of the designed method.The statistical analysis is performed using different measures for 30 independent runs as well as 15 variables to authenticate the consistency of the proposed method.The plots of the absolute error,convergence analysis,histogram,performancemeasures,and boxplots are also provided to find the exactness,dependability and stability of the MWNN-GA-ASA.

关键词： Nonlinear SITR model morlet function artificial neural networks runge-kutta treatment genetic algorithm treatment active-set