Nowadays, new energy has been massively accessed to the distribution network. Since its complex topological structure and control characteristics increase the complexity of the new energy source model, it is necessary...
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ISBN:
(纸本)9781538614273
Nowadays, new energy has been massively accessed to the distribution network. Since its complex topological structure and control characteristics increase the complexity of the new energy source model, it is necessary to study the simplifiedmodeling of new energy sources for the relay protection simulation analysis. Utilizing the modeling idea of testing and analysis and the simplified modeling method based on experimental data, the author treats the generation unit with complex architecture and control information as a black-box model in this paper. The fault current expression is depicted by means of the typical control system response;meanwhile, the relationship between the fault current expression and the fault voltage amplitude is created with sample data of the voltage drop test, the nonlinear mapping relationship between fault current and fault voltage is obtained, thus the new energy source model can be equivalent to a voltage controlled current source. Taking the Doubly Fed Induction Generators (DFIGs) as the modeling object and using fine modeling to simulate the transient fault under symmetrical short circuit conditions, the author establishes a simplified model with the consequential sample data.
This paper proposes and analyzes some simplified dynamic modelingmethods for parallel robots. The proposed methods are based on a Lagrangian approach where the key concept consists in simplifying the expression of th...
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This paper proposes and analyzes some simplified dynamic modelingmethods for parallel robots. The proposed methods are based on a Lagrangian approach where the key concept consists in simplifying the expression of the energy for robots, especially for the distal links. First, the slender link method is discussed, where the link energy is calculated from the endpoints' velocities. Then, the commonly used equivalent point mass (EPM) method is analyzed. Since the EPM method uses point masses to replace links, the main problem is how to assign the values of point masses. According to the energy equivalence principle, some methods are proposed to solve the value-assigning problem. The derivations of the proposed methods are given, and the errors caused by each method are analyzed. Based on the error analyses, some simple approaches are introduced to improve the accuracy of the EPM methods. Inverse dynamic models of a spatial robot are established based on the proposed methods. Then, detailed comparisons and analyses of the different dynamic models are given to show that the proposed methods are simple and have relatively high accuracy.
The complex simulation calculation process and slow solving speed are important factors that constrain the development of modular multi-level device simulation modeling. In this paper, the equivalent modeling of modul...
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A method of simplifiedmodeling based on Part Influence Coefficient (PIC) for vehicle crash is presented. A frontal impact model of minibus is established and verified by comparing with crash test. Through the researc...
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A method of simplifiedmodeling based on Part Influence Coefficient (PIC) for vehicle crash is presented. A frontal impact model of minibus is established and verified by comparing with crash test. Through the research of the influence of typical parts, the Vehicle Acceleration Criterion and Part Influence Coefficient are investigated. The simplified modeling method is presented in combination with weight control method and requirement of data output. The results show that the simplified model provides the deformation and energy absorption, the acceleration of body and engine, and the intrusion of parts accurately. The vehicle crashworthiness is fully considered in the design by the simplifiedmethod, and the computing time is reduced by 53% in the minibus case.
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