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Overview of Precious Metal Content Analysis Methods in Automotive Catalytic Converter 被引量:1
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作者 Xianpeng Yang Chengbao Xie +4 位作者 Ning Liu Xin Du Suqing Wang Huasheng Jiang Zhengang Zhang 《Journal of Materials Science and Chemical Engineering》 2023年第11期7-14,共8页
With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attenti... With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attention. The catalytic converter is able to purify harmful substances in exhaust gas. The absolute content of precious metals in the catalytic converter dominates the exhaust gas purification effect. Accurate detection of precious metal content is of great significance for controlling the cost of catalysts, ensuring catalytic performance and recovering precious metals from spent catalysts. We herein summarized several instruments for precious metals content exploration, such as X-ray fluorescence spectrometer (XRF), atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP) and spectrophotometer. In this thesis, the feasibility of using various devices for characterizing precious metal content in catalytic converters is analyzed and their strengths or weaknesses are elaborated. 展开更多
关键词 Catalytic converter Precious Metal Content analysis Methods
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Response Spectrum Analysis of 7-story Assembled Frame Structure with Energy Dissipation System
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作者 Jin Zhao Yi Wang Zhengwei Ma 《Structural Durability & Health Monitoring》 EI 2023年第2期159-173,共15页
Viscoelastic damper is an effective passive damping device,which can reduce the seismic response of the structure by increasing the damping and dissipating the vibration energy of structures.It has a wide application ... Viscoelastic damper is an effective passive damping device,which can reduce the seismic response of the structure by increasing the damping and dissipating the vibration energy of structures.It has a wide application prospect in actual structural vibration control because of simple device and economical material.In view of the poor seismic behaviors of assembled frame structure connections,various energy dissipation devices are proposed to improve the seismic performance.The finite element numerical analysis method is adopted to analyze relevant energy dissipation structural parameters.The response spectrum of a 7-story assembled frame structure combined the ordinary steel support,ordinary viscoelastic damper,and viscoelastic damper with displacement amplification device is analyzed.The analysis results show that the mechanical behavior of assembled frame structure with ordinary steel supports are not significantly different from those without energy dissipation devices.The assembled frame structure with viscoelastic damper has better seismic performance and energy dissipation,especially for the viscoelastic damper with displacement amplification devices.The maximum value of inter-story displacement angle decreases by 32.24%;the maximum floor displacement decreases by 31.91%,and the base shear decreases by 13.62%compared with the assembled frame structures without energy dissipation devices.The results show that the seismic fortification ability of the structure is significantly improved,and the overall structure is more uniformly stressed.The damping structure with viscoelastic damper mainly reduces the dynamic response of the structure by increasing the damping coefficient,rather than by changing the natural vibration period of the structure.This paper provides an effective theoretical basis and reference for improving the energy dissipation system and the seismic performance of assembled frame structures. 展开更多
关键词 Assembled frame structure energy dissipation devices response spectrum analysis viscoelastic damper
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Thermal Dissipation Modelling and Design of ITER PF Converter Alternating Current Busbar 被引量:2
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作者 郭斌 宋执权 +4 位作者 傅鹏 蒋力 李金超 王敏 董琳 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第10期1049-1054,共6页
Because the larger metallic surrounds are heated by the eddy current, which is generated by the AC current flowing through the AC busbar in the International Thermonuclear ExperimentM Reactor (ITER) poloidal field ... Because the larger metallic surrounds are heated by the eddy current, which is generated by the AC current flowing through the AC busbar in the International Thermonuclear ExperimentM Reactor (ITER) poloidal field (PF) converter system, shielding of the AC busbar is required to decrease the temperature rise of the surrounds to satisfy the design requirement. Three special types of AC busbar with natural cooling, air cooling and water cooling busbar structure have been proposed and investigated in this paper. For each cooling scheme, a 3D finite model based on the proposed structure has been developed to perform the electromagnetic and thermal analysis to predict their operation behavior. Comparing the analysis results of the three different cooling patterns, water cooling has more advantages than the other patterns and it is selected to be the thermal dissipation pattern for the AC busbar of ITER PF converter unit. The approach to qualify the suitable cooling scheme in this paper can be provided as a reference on the thermal dissipation design of AC busbar in the converter system. 展开更多
关键词 thermal dissipation modelling and design AC busbar converter
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NUMERICAL ANALYSIS ON THREE-DIMENSIONAL FLOW FIELD OF TURBINE IN TORQUE CONVERTER 被引量:11
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作者 LIU Yue PAN Yuxue LIU Chunbao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第2期94-96,共3页
Three-dimensional flow field of turbine in torque converter is simulated by numerical calculation in order to improve the performance of torque converter. Calculation model of a torque converter is presented based on ... Three-dimensional flow field of turbine in torque converter is simulated by numerical calculation in order to improve the performance of torque converter. Calculation model of a torque converter is presented based on the mixing-plane technology. In the calculation of flow field, the 3D N-S equations are separated by finite-volume method and solved by semi-implicit method for pressure-linked equations(SIMPLE). Based on flow field calculation, the flow field of turbine is simulated. The velocity and pressure in the flow field of turbine are analyzed. The external performance of the torque converter is also calculated. Results of flow simulation show that there are secondary flow, off flow and velocity gradient in turbine passage. The validity of numerical simulation is verified by comparing the results of numerical simulation with experiment data. 展开更多
关键词 Torque converter Turbine Flow field Numerical analysis
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Current Sharing Analysis of Arm Prototype for ITER PF Converter Bridge 被引量:2
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作者 李金超 宋执权 +5 位作者 许留伟 傅鹏 郭斌 李森 董琳 王敏 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第3期283-287,共5页
A bridge arm prototype of ITER poloidal field (PF) converter modules has been designed and fabricated. Non-cophase counter parallel connection is chosen as the arm structure of the prototype. Among all factors affec... A bridge arm prototype of ITER poloidal field (PF) converter modules has been designed and fabricated. Non-cophase counter parallel connection is chosen as the arm structure of the prototype. Among all factors affecting current sharing, arm structure is the main one. During the design of the arm prototype, a novel method based on inductance matrixes is employed to improve the current sharing of the bridge arm. The test results on the prototype show that the current sharing performance of the arm prototype is much better than relevant design requirement, and that the matrix method is very effective to analyze and solve the current sharing problems of thyristor converters. 展开更多
关键词 thyristor converter current sharing electromagnetic analysis inductance ma-trix
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NEW PERTURBATION TECHNIQUE FOR TRANSIENT ANALYSIS AND ITS APPLICATIONS IN DC-DC PWM SWITCHING POWER CONVERTERS 被引量:1
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作者 Lin Botao Qiu Shuisheng(Department of Electronic Engineering, South China University of Technology, Guang Zhou 510641) 《Journal of Electronics(China)》 1997年第4期357-366,共10页
An improved perturbation technique proposed in a recent paper (Int. J. Electronics, vol. 63, pp.403-414) has been successfully applied to steady-state analysis of PWM switching converters. This paper extends the algor... An improved perturbation technique proposed in a recent paper (Int. J. Electronics, vol. 63, pp.403-414) has been successfully applied to steady-state analysis of PWM switching converters. This paper extends the algorithm to transient analysis of a broader class of non-linear systems. As an example, the transient response of a Boost PWM switching converter is analyzed to demonstrate its simplicity and accuracy. 展开更多
关键词 ASYMPTOTIC method TRANSIENT analysis SWITCHING converterS NONLINEAR systems
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Modeling and Dynamic Analysis of Fractional-Order Buck Converter in Continuous Conduction Mode 被引量:1
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作者 Dawei Ding Zongzhi Li Nian Wang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2019年第4期58-68,共11页
According to the fact that the actual inductor and actual capacitor are fractional, the mathematical and state-space averaging models of fractional order Buck converters in continuous conduction mode(CCM) are construc... According to the fact that the actual inductor and actual capacitor are fractional, the mathematical and state-space averaging models of fractional order Buck converters in continuous conduction mode(CCM) are constructed by using fractional calculus theory. Firstly, the parameter conditions that ensure that the converter working in CCM is given and transfer functions are derived. Also, the inductor current and the output voltage are analyzed. Then the difference between the mathematical model and the circuit model are analyzed, and the effect of fractional order is studied by comparing the integer order with fractional order model. Finally, the dynamic behavior of the current-controlled Buck converter is investigated. Simulation experiments are achieved via the use of Matlab/Simulink. The experimental results verify the correctness of theoretical analysis, the order should be taken as a significant parameter. When the order is taken as a bifurcation parameter, the dynamic behavior of the converter will be affected and bifurcation points will be changed as order varies. 展开更多
关键词 BUCK converter FRACTIONAL order continuous conduction mode(CCM) MODELING dynamic analysis BIFURCATION
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Modal analysis of the torque converter in different prestress 被引量:1
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作者 Zhang Zeyu Hui Jizhuang +3 位作者 Shi Ze Suo Xuefeng Zhang Xuhui Fan Hongwei 《High Technology Letters》 EI CAS 2020年第1期61-67,共7页
In order to study the mechanical properties and the dynamic performance of torque converter,to reduce the vibration and noise during the operation and to improve the stability,a 215 mm hydraulic torque converter is ta... In order to study the mechanical properties and the dynamic performance of torque converter,to reduce the vibration and noise during the operation and to improve the stability,a 215 mm hydraulic torque converter is taken as the research object,and modal analyses are performed based on the finite element method.The weak parts of the impeller structure are obtained after calculating the models of the impeller and turbine without prestress.The variation of the modal frequency of the turbine and impeller are obtained under different prestress conditions by calculating different rotational speeds of the transmission shaft.The fundamental frequencies of the impeller and the turbine increase by 0.43%and 4.82%respectively when the rotational speed ranges from 100 rpm to 4500 rpm.The results of the present research indicate that the modal frequencies at different speeds are similar to the fundamental frequencies of the structure.Therefore,it is possible to estimate the vibration characteristics of the structure and optimize the structural design by numerical modal analysis in the static state instead of the dynamic state. 展开更多
关键词 HYDRAULIC TORQUE converter MODAL analysis PRESTRESS FINITE element analysis
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Fluid-solid interaction analysis of torque converters 被引量:1
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作者 Zhang Zeyu Hui Jizhuang +2 位作者 Suo Xuefeng Zhang Fuqiang Lei Jingyuan 《High Technology Letters》 EI CAS 2019年第3期239-244,共6页
In order to extend the service life of torque converters, it is essential to predict the pressure condition and improve its weak areas. According to computational fluid dynamics and structural statics, a model of torq... In order to extend the service life of torque converters, it is essential to predict the pressure condition and improve its weak areas. According to computational fluid dynamics and structural statics, a model of torque converter is constructed using software ANSYS. Then, a fluid-solid interaction(FSI) analysis method is proposed to obtain its stress distribution, in which the fluid pressure is applied to the coupling surface to calculate the interaction between fluid and solid. The results show that the fluid pressure at the inlet of the impeller is maximum and decreases along the flow direction, the pressure at the inlet of the turbine blade is minimum and the outlet pressure is the largest, increasing along the flow direction gradually;the pressure distribution of the impeller is concentrated mainly at the corner, especially between the inner ring and the impeller blades;the pressure of the turbine is concentrated mainly on the connection between turbine and the outer edge of the blade. 展开更多
关键词 torque converter fluid-solid interaction(FSI) stress distribution pressure analysis SIMULATION
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Residue analysis and dissipation of a new fungicide 2-allylphenol in tomato
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作者 HUJi-ye ZHANGWen-ji LIJian-zhong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第3期491-493,共3页
The method of residue analysis of a new synthesized fungicide 2-allylphenol was studied by simulating the active compound structure in Gingko tree(Gingko biloba L.) and its dissipation rate and terminal residue levels... The method of residue analysis of a new synthesized fungicide 2-allylphenol was studied by simulating the active compound structure in Gingko tree(Gingko biloba L.) and its dissipation rate and terminal residue levels in tomato under field condition. Residues of 2-allylphenol were extracted from tomato matrix with acetone, purified by liquid-liquid extraction and Florisil cartrieges, and then determined by HPLC with UV-detector. The minimum detectable amount of 2-allylphenol was 3×10 -9 g, the minimum detectable concentration of 2-allylphenol in the samples of tomato were 0.01 mg/kg. The ranges of average recoveries and coefficient variation of the method were 87.7%—90.2% and 1.25%—2.06%, respectively. The dissipation rate and terminal residue levels in tomato were determined with the method described above. The results showed that the half-life of 2-allylphenol in tomato was 6.37 d, and 2-allylphenol declined with 82.6% of the initial deposit remaining in tomato at harvest. The terminal residue levels in tomato were 0.15 mg/kg and 0.20 mg/kg following the recommended doses and time intervals. 展开更多
关键词 FUNGICIDE 2-allylphenol residue analysis dissipation
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DYNAMIC RESPONSE AND ENERGY DISSIPATION ANALYSIS OF THE WALL WITH HORIZONTAL SHORT KEYWAYS AND LOWRISE SHEARWALL
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作者 戴航 丁大钧 《Journal of Southeast University(English Edition)》 EI CAS 1993年第1期33-39,共7页
A new type of ductile lowrise shearwall with many short horizontalkeyways is proposed in this paper in order to improve the earthquake resistant behav-ior of ordinary lowrise shearwall.The behavior of this wall is stu... A new type of ductile lowrise shearwall with many short horizontalkeyways is proposed in this paper in order to improve the earthquake resistant behav-ior of ordinary lowrise shearwall.The behavior of this wall is studied through low-frequency cyclic loading test.Based on the test results,the paper puts forward thedifferent restoring force models for different lowrise shearwalls,and a program fortheir nonlinear dynamic analysis is worked out.Thr(?)h directly inputting earth-quake waves,the paper analyses the dynamic response and energy dissipation of 3types of lowrise shearwalls.The calculation results dem(?)strate that the newly de-vised ductile shearwall has good earthquake resistant behavior. 展开更多
关键词 DUCTILE SHEAR WALL dynamic structural analysis energy dissipation
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EFFICIENT STEADY-STATE ANALYSIS METHOD FOR CLOSED-LOOP PWM SWITCHING CONVERTERS
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作者 尹有为 马西奎 《Journal of Pharmaceutical Analysis》 SCIE CAS 2006年第1期6-12,共7页
An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means... An analysis technique of steady state and stability for closed-loop PWM DC/DC switching converters is presented. Using this method, the closed-loop switching converter is transformed into an open-loop system. By means of the fact that in steady state, the two boundary values are equal in one switching period. The exponential matrix is evaluated by precise time-domain-integration method, and then the related curve between feedback duty cycle and the input one is obtained. Not only can the steady-state duty cycle be found from the curve, but also the stability and stable domain of the system. Compared with other methods, it features with simplicity and less calculation, and fit for numerical simulation and analysis for closed-loop switching converters. The simulation results of examples indicate the correctness of the presented method. 展开更多
关键词 closed-loop system STEADY-STATE stability analysis switching converters
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Design and Analysis of the Main AC/DC Converter System for ITER
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作者 盛志才 许留伟 傅鹏 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第4期338-342,共5页
A design of the main AC/DC converter system for ITER is described and the configuration of the main AC/DC converters is presented. To reduce the reactive power absorbed from the converter units, the main AC/DC convert... A design of the main AC/DC converter system for ITER is described and the configuration of the main AC/DC converters is presented. To reduce the reactive power absorbed from the converter units, the main AC/DC converters are designed to be series-connected and work in a sequential mode. The structure of the regulator of the converter system is described. A simulation model was built up for the PSCAD/EMTDC code, and the design was validated accordingly. Harmonic analysis and reactive power calculation of the converters units are presented. The results reveal the advantage of sequential control in reducing reactive power and harmonics. 展开更多
关键词 AC/DC converter sequential control harmonic analysis reactive power reduction
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Short-circuit fault analysis and isolation strategy for matrix converters
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作者 王莉娜 L.De Lillo +2 位作者 C.Brunson L.Empringham P.Wheeler 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3458-3470,共13页
The behavior of matrix converter(MC) drive systems under the condition of MC short-circuit faults is comprehensively investigated. Two isolation strategies using semiconductors and high speed fuses(HSFs) for MC short-... The behavior of matrix converter(MC) drive systems under the condition of MC short-circuit faults is comprehensively investigated. Two isolation strategies using semiconductors and high speed fuses(HSFs) for MC short-circuit faults are examined and their performances are compared. The behavior of MC drive systems during the fuse action time under different operating conditions is explored. The feasibility of fault-tolerant operation during the fuse action time is also studied. The basic selection laws for the HSFs and the requirements for the passive components of the MC drive system from the point view of short-circuit faults are also discussed. Simulation results are used to demonstrate the feasibility of the proposed isolation strategies. 展开更多
关键词 matrix converter short-circuit fault fault analysis fault behavior fault isolation
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Analysis of Transforming dq Impedances of Different Converters to A Common Reference Frame in Complex Converter Networks
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作者 Qi Xiao Paolo Mattavelli +1 位作者 Aram Khodamoradi Fen Tang 《CES Transactions on Electrical Machines and Systems》 CSCD 2019年第4期342-350,共9页
DQ impedance-based method has been widely used to study the stability of three-phase converter systems.As the dq impedance model of each converter depends on its local dq reference frame,the dq impedance modeling of c... DQ impedance-based method has been widely used to study the stability of three-phase converter systems.As the dq impedance model of each converter depends on its local dq reference frame,the dq impedance modeling of complex converter networks gets complicated.Because the reference frames of different converters might not fully align,depending on the structure.Thus,in order to find an accurate impedance model of a complex network for stability analysis,converting the impedances of different converters into a common reference frame is required.This paper presents a comprehensive investigation on the transformation of dq impedances to a common reference frame in complex converter networks.Four different methods are introduced and analyzed in a systematic way.Moreover,a rigorous comparison among these approaches is carried out,where the method with the simplest transformation procedure is finally suggested for the modeling of complex converter networks.The performed analysis is verified by injecting two independent small-signal perturbations into the d and the q axis,and doing a point-by-point impedance measurement. 展开更多
关键词 Complex converter networks impedance transformation synchronous rotating dq frame stability analysis.
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Sulfur poisoning mechanism of three way catalytic converter and its grey relational analysis
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作者 蔡皓 刘亚飞 +3 位作者 龚金科 鄂加强 耿玉鹤 余立平 《Journal of Central South University》 SCIE EI CAS 2014年第11期4091-4096,共6页
Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, ste... Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC. 展开更多
关键词 sulfur poisoning three-way catalytic converter reaction mechanism numerical simulation grey relational analysis
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Effect of Different Raft Shapes on Hydrodynamic Characteristics of the Attenuator-Type Wave Energy Converter
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作者 WANG Jin WANG Shu-qi +2 位作者 JIANG Qing-dian XU Yun-xin SHI Wei-chao 《China Ocean Engineering》 SCIE EI CSCD 2023年第4期645-659,共15页
A numerical simulation method based on CFD has been established to simulate the fully coupled motion for an atten-uator-type wave energy converter(WEC).Based on this method,a detailed parametric analysis has been cond... A numerical simulation method based on CFD has been established to simulate the fully coupled motion for an atten-uator-type wave energy converter(WEC).Based on this method,a detailed parametric analysis has been conducted to investigate the design of the rafts.The effects of different parameters(wave parameters,structural parameters and PTO parameters)on the hydrodynamic characteristics of the attenuator-type WEC were studied in detail.The results show that in terms of wave parameters,there is an optimal wave period,which makes the relative pitching angle amplitude of the WEC reach the maximum,and the increase of wave height is conducive to the relative pitching angle amplitude of wave energy.Under different wave conditions,the relative pitch angle of the parallelogram raft device is the maximum.In terms of structural parameters,the parallelogram attenuator-type device has the optimal values in different relative directions,different distances and different apex angle,which makes the relative motion amplitude of the device reach the maximum,and the spacing and the apex angle have influence on the motion frequency of the device,while the relative direction has almost no influence on it.In terms of PTO parameters,there is an optimal damping coefficient,which makes the power generation efficiency of the WEC reach the maximum.The research results provide a valuable reference for future research and design of the attenuator-type WEC. 展开更多
关键词 wave energy converter attenuator-type shape hydrodynamic analysis power generation efficiency
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Influence of dissipation on solitary wave solution to generalized Boussinesq equation
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作者 Weiguo ZHANG Siyu HONG +1 位作者 Xingqian LING Wenxia LI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第3期477-498,共22页
This paper uses the theory of planar dynamic systems and the knowledge of reaction-diffusion equations,and then studies the bounded traveling wave solution of the generalized Boussinesq equation affected by dissipatio... This paper uses the theory of planar dynamic systems and the knowledge of reaction-diffusion equations,and then studies the bounded traveling wave solution of the generalized Boussinesq equation affected by dissipation and the influence of dissipation on solitary waves.The dynamic system corresponding to the traveling wave solution of the equation is qualitatively analyzed in detail.The influence of the dissipation coefficient on the solution behavior of the bounded traveling wave is studied,and the critical values that can describe the magnitude of the dissipation effect are,respectively,found for the two cases of b_3<0 and b_3>0 in the equation.The results show that,when the dissipation effect is significant(i.e.,r is greater than the critical value in a certain situation),the traveling wave solution to the generalized Boussinesq equation appears as a kink-shaped solitary wave solution;when the dissipation effect is small(i.e.,r is smaller than the critical value in a certain situation),the traveling wave solution to the equation appears as the oscillation attenuation solution.By using the hypothesis undetermined method,all possible solitary wave solutions to the equation when there is no dissipation effect(i.e.,r=0)and the partial kink-shaped solitary wave solution when the dissipation effect is significant are obtained;in particular,when the dissipation effect is small,an approximate solution of the oscillation attenuation solution can be achieved.This paper is further based on the idea of the homogenization principles.By establishing an integral equation reflecting the relationship between the approximate solution of the oscillation attenuation solution and the exact solution obtained in the paper,and by investigating the asymptotic behavior of the solution at infinity,the error estimate between the approximate solution of the oscillation attenuation solution and the exact solution is obtained,which is an infinitesimal amount that decays exponentially.The influence of the dissipation coefficient on the amplitude,frequency,period,and energy of the bounded traveling wave solution of the equation is also discussed. 展开更多
关键词 generalized Boussinesq equation influence of dissipation qualitative analysis solitary wave solution oscillation attenuation solution error estimation
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Four-parameter velocity analysis and its applications to the Ken-71 area converted-wave data 被引量:2
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作者 石建新 《Applied Geophysics》 SCIE CSCD 2008年第1期50-56,共7页
3-D converted-wave data were acquired using digital MEMS (micro-electromechanical system) three component (3C) sensors in the alternating sand and shale sequence in the overburden of the Shengli Ken-71 area. This ... 3-D converted-wave data were acquired using digital MEMS (micro-electromechanical system) three component (3C) sensors in the alternating sand and shale sequence in the overburden of the Shengli Ken-71 area. This gives rise to serious non-hyperbolic moveout effects in the converted-wave data due to both the asymmetrical ray path and anisotropic effects. Conventional velocity analysis and moveout correction based on isotropic methods do not flatten reflections events. Here, we use a four-parameter theory to evaluate these effects and process the data. These four parameters include the PS converted wave stacking velocity (Vc2), the vertical velocity ratio (Y0), the effective velocity ratio (Yeff), and the anisotropy parameter (xoff), The method utilizes the moveout information at different offsets to estimate the different parameters and ensures that the events are properly aligned for stacking, As a result, this four-parameter theory leads to an improvement in imaging quality and correlation between the P-waves and converted-waves. 展开更多
关键词 converted waves four-parameter velocity analysis prestack time migration.
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Analysis and Optimization of Boost Converter Parameters in Internal Model Control for Voltage Source Converter-based AC Microgrids
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作者 Chiebuka Eyisi Qifeng Li 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第5期2038-2054,共17页
This paper investigates integration of distributed energy resources(DERs)in microgrids(MGs)through two-stage power conversion structures consisting of DC-DC boost converter and DC-AC voltage source converter(VSC)subsy... This paper investigates integration of distributed energy resources(DERs)in microgrids(MGs)through two-stage power conversion structures consisting of DC-DC boost converter and DC-AC voltage source converter(VSC)subsystems.In contrast to existing investigations that treated DC-link voltage as an ideal constant voltage,this paper considers the non-ideal dynamic coupling between both subsystems for completeness and higher accuracy,which introduces additional DC-side dynamics to the VSC.The analysis shows parameters of the boost converter’s power model that impact stability through the DC-link.Carefully selecting these parameters can mitigate this effect on stability and improve dynamic performance across the DC-link.Hence,an optimization framework is developed to facilitate in selecting adequate boost converter parameters in designing a stable voltage source converter-based microgrid(VSC-MG).The developed optimization framework,based on particle swarm optimization,considers dynamic coupling between both subsystems and is also effective in avoiding inadequate boost converter parameters capable of propagating instability through the DC-link to the VSC.Simulations are performed with MATLAB/Simulink to validate theoretical analyses. 展开更多
关键词 AC microgrid boost converter DEAD-TIME droop control internal model control particle swarm optimization small-signal analysis time delay virtual impedance voltage source converter
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