The subsynchronous oscillations(SSOs)related to renewable generation seriously affect the stability and safety of the power systems.To realize the dynamic monitoring of SSOs by utilizing the high computational efficie...The subsynchronous oscillations(SSOs)related to renewable generation seriously affect the stability and safety of the power systems.To realize the dynamic monitoring of SSOs by utilizing the high computational efficiency and noise-resilient features of the matrix pencil method(MPM),this paper propos es an improved MPM-based parameter identification with syn chrophasors.The MPM is enhanced by the angular frequency fitting equations based on the characteristic polynomial coeffi cients of the matrix pencil to ensure the accuracy of the identi fied parameters,since the existing eigenvalue solution of the MPM ignores the angular frequency conjugation constraints of the two fundamental modes and two oscillation modes.Then,the identification and recovery of bad data are proposed by uti lizing the difference in temporal continuity of the synchropha sors before and after noise reduction.The proposed parameter identification is verified with synthetic,simulated,and actual measured phase measurement unit(PMU)data.Compared with the existing MPM,the improved MPM achieves better accuracy for parameter identification of each component in SSOs,better real-time performance,and significantly reduces the effect of bad data.展开更多
A modified matrix enhancement and matrix pencil (MMEMP) method is presented for the scattering centers measurements in step-frequency radar. The method estimates the signal parameter pairs directly unlike the matrix e...A modified matrix enhancement and matrix pencil (MMEMP) method is presented for the scattering centers measurements in step-frequency radar. The method estimates the signal parameter pairs directly unlike the matrix enhancement and matrix pencil (MEMP) method which contains an additional step to pair the parameters related to each dimension. The downrange and crossrange expressions of the scattering centers are deduced, as well as the range ambiguities, from the point of view of MMEMP method. Compared with the Fourier transform method, the numerical simulation shows that both the resolution and precision of the MMEMP method are higher than those of the Fourier method. The processing results of the real measured data for three cylinders prove the above conclusions further.展开更多
The problem of correcting simultaneously mass and stiffness matrices of finite element model of undamped structural systems using vibration tests is considered in this paper.The desired matrix properties,including sat...The problem of correcting simultaneously mass and stiffness matrices of finite element model of undamped structural systems using vibration tests is considered in this paper.The desired matrix properties,including satisfaction of the characteristic equation,symmetry,positive semidefiniteness and sparsity,are imposed as side constraints to form the optimal matrix pencil approximation problem.Using partial Lagrangian multipliers,we transform the nonlinearly constrained optimization problem into an equivalent matrix linear variational inequality,develop a proximal point-like method for solving the matrix linear variational inequality,and analyze its global convergence.Numerical results are included to illustrate the performance and application of the proposed method.展开更多
To aim at the distribution parameter characteristics of UHV transmission line, this paper presents a fast extraction method (FE) to extract the accurate fundamentals of current and voltage from the UHV transmission li...To aim at the distribution parameter characteristics of UHV transmission line, this paper presents a fast extraction method (FE) to extract the accurate fundamentals of current and voltage from the UHV transmission line transient process, and locates the fault by utilizing two-end unsynchronized algorithm. The simulation result shows that this method has good performance of accuracy and stability, and has better location precision by comparing with results of one cycle Fourier algorithm. Therefore the method can efficiently improve the precision of fault location during the transient process, and makes the error of location results less than 0.5%.展开更多
Deep geothermal energy presents large untapped renewable energy potential could significantly contribute to global energy needs. However, developing geothermal projects involves uncertainties regarding adequate geothe...Deep geothermal energy presents large untapped renewable energy potential could significantly contribute to global energy needs. However, developing geothermal projects involves uncertainties regarding adequate geothermal brine extraction and huge costs related to preparation phases and consequently drilling and stimulation activities. Therefore, evaluating utilization alternatives of such projects is a complex decision-making problem effectively addressed using multi-criteria decision-making (MCDM) methods. This study introduces the MCDM method utilizing analytic hierarchy process (AHP) and weighted decision matrix (WDM) to assess different utilization alternatives (electricity generation, direct heat use and cogeneration). The AHP method determines the weight of each criterion and sub-criterion, while the WDM calculates the final project grade. Five criteria groups - technological, geological, economic, societal and environmental – comprising twenty-eight influencing factors were selected and used for the assessment of investment in Enhanced Geothermal Systems (EGS) projects. The AHP-WDM method was used by 38 experts from six categories: industry, educational institution, research and technology organization (RTO), small- and medium-sized enterprises (SME), local community and other. These diverse expert inputs aimed to capture varying perspectives and knowledge influence investment decisions in geothermal energy. The results were analysed accordingly. The results underscore the importance of incorporating different viewpoints to develop robust, credible, and effective investment strategies for EGS projects. Therefore, this method will contribute to more efficient EGS project development, enabling thus a greater penetration of the EGS into the market. Additionally, the proposed AHP-WDM method was implemented for a case study examining two locations. Locations were assessed and compared on scenario-based evaluation. The results confirmed the method's adequacy for assessing various end uses and comparing project feasibility across different locations.展开更多
基于增广矩阵束方法(Matrix Enhancement and Matrix Pencil,MEMP),以使用尽可能少的阵元逼近期望的方向图为目标,提出了一种求解阵元位置和设计激励幅度的新方法.首先对期望平面阵的方向图进行采样得到离散的数据集,再构造增广矩阵,对...基于增广矩阵束方法(Matrix Enhancement and Matrix Pencil,MEMP),以使用尽可能少的阵元逼近期望的方向图为目标,提出了一种求解阵元位置和设计激励幅度的新方法.首先对期望平面阵的方向图进行采样得到离散的数据集,再构造增广矩阵,对此增广矩阵进行奇异值分解(Singular Value Decomposition,SVD),确定逼近期望方向图所需的最小阵元数目;基于广义特征值分解求解两组特征值,并根据类基于旋转不变技术的信号参数估计(Estimating Signal Parameters Via RotationalInvariance Techniques,ESPRIT)对这两组特值配对;在最小二乘准则下求解稀布面阵的阵元位置和激励.仿真试验验证了该方法在稀布平面阵优化问题中的高效性和数值精度.展开更多
基金supported by National Natural Science Foundation of China(No.52077004).
文摘The subsynchronous oscillations(SSOs)related to renewable generation seriously affect the stability and safety of the power systems.To realize the dynamic monitoring of SSOs by utilizing the high computational efficiency and noise-resilient features of the matrix pencil method(MPM),this paper propos es an improved MPM-based parameter identification with syn chrophasors.The MPM is enhanced by the angular frequency fitting equations based on the characteristic polynomial coeffi cients of the matrix pencil to ensure the accuracy of the identi fied parameters,since the existing eigenvalue solution of the MPM ignores the angular frequency conjugation constraints of the two fundamental modes and two oscillation modes.Then,the identification and recovery of bad data are proposed by uti lizing the difference in temporal continuity of the synchropha sors before and after noise reduction.The proposed parameter identification is verified with synthetic,simulated,and actual measured phase measurement unit(PMU)data.Compared with the existing MPM,the improved MPM achieves better accuracy for parameter identification of each component in SSOs,better real-time performance,and significantly reduces the effect of bad data.
文摘A modified matrix enhancement and matrix pencil (MMEMP) method is presented for the scattering centers measurements in step-frequency radar. The method estimates the signal parameter pairs directly unlike the matrix enhancement and matrix pencil (MEMP) method which contains an additional step to pair the parameters related to each dimension. The downrange and crossrange expressions of the scattering centers are deduced, as well as the range ambiguities, from the point of view of MMEMP method. Compared with the Fourier transform method, the numerical simulation shows that both the resolution and precision of the MMEMP method are higher than those of the Fourier method. The processing results of the real measured data for three cylinders prove the above conclusions further.
基金The work was supported by the National Natural Science Foundation of China(No.11571171)。
文摘The problem of correcting simultaneously mass and stiffness matrices of finite element model of undamped structural systems using vibration tests is considered in this paper.The desired matrix properties,including satisfaction of the characteristic equation,symmetry,positive semidefiniteness and sparsity,are imposed as side constraints to form the optimal matrix pencil approximation problem.Using partial Lagrangian multipliers,we transform the nonlinearly constrained optimization problem into an equivalent matrix linear variational inequality,develop a proximal point-like method for solving the matrix linear variational inequality,and analyze its global convergence.Numerical results are included to illustrate the performance and application of the proposed method.
文摘To aim at the distribution parameter characteristics of UHV transmission line, this paper presents a fast extraction method (FE) to extract the accurate fundamentals of current and voltage from the UHV transmission line transient process, and locates the fault by utilizing two-end unsynchronized algorithm. The simulation result shows that this method has good performance of accuracy and stability, and has better location precision by comparing with results of one cycle Fourier algorithm. Therefore the method can efficiently improve the precision of fault location during the transient process, and makes the error of location results less than 0.5%.
基金funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 792037support from Department of Energy and Power Systems of University of Zagreb Faculty of Electrical Engineering and Computing.
文摘Deep geothermal energy presents large untapped renewable energy potential could significantly contribute to global energy needs. However, developing geothermal projects involves uncertainties regarding adequate geothermal brine extraction and huge costs related to preparation phases and consequently drilling and stimulation activities. Therefore, evaluating utilization alternatives of such projects is a complex decision-making problem effectively addressed using multi-criteria decision-making (MCDM) methods. This study introduces the MCDM method utilizing analytic hierarchy process (AHP) and weighted decision matrix (WDM) to assess different utilization alternatives (electricity generation, direct heat use and cogeneration). The AHP method determines the weight of each criterion and sub-criterion, while the WDM calculates the final project grade. Five criteria groups - technological, geological, economic, societal and environmental – comprising twenty-eight influencing factors were selected and used for the assessment of investment in Enhanced Geothermal Systems (EGS) projects. The AHP-WDM method was used by 38 experts from six categories: industry, educational institution, research and technology organization (RTO), small- and medium-sized enterprises (SME), local community and other. These diverse expert inputs aimed to capture varying perspectives and knowledge influence investment decisions in geothermal energy. The results were analysed accordingly. The results underscore the importance of incorporating different viewpoints to develop robust, credible, and effective investment strategies for EGS projects. Therefore, this method will contribute to more efficient EGS project development, enabling thus a greater penetration of the EGS into the market. Additionally, the proposed AHP-WDM method was implemented for a case study examining two locations. Locations were assessed and compared on scenario-based evaluation. The results confirmed the method's adequacy for assessing various end uses and comparing project feasibility across different locations.
文摘基于增广矩阵束方法(Matrix Enhancement and Matrix Pencil,MEMP),以使用尽可能少的阵元逼近期望的方向图为目标,提出了一种求解阵元位置和设计激励幅度的新方法.首先对期望平面阵的方向图进行采样得到离散的数据集,再构造增广矩阵,对此增广矩阵进行奇异值分解(Singular Value Decomposition,SVD),确定逼近期望方向图所需的最小阵元数目;基于广义特征值分解求解两组特征值,并根据类基于旋转不变技术的信号参数估计(Estimating Signal Parameters Via RotationalInvariance Techniques,ESPRIT)对这两组特值配对;在最小二乘准则下求解稀布面阵的阵元位置和激励.仿真试验验证了该方法在稀布平面阵优化问题中的高效性和数值精度.
