功率连接型数字物理混合仿真系统 (一)接口算法特性

功率连接型数字物理混合仿真结合了实时数字仿真和动态物理模拟的优点,是未来研究新能源发电和储能设备物理特性和接入技术的关键手段。接口算法是功率连接型混合仿真系统的关键技术。文中从稳定性和精确性2个方面,研究并建立了功率连接型混合仿真系统的接口特性。对阻抗阻尼接口进行了化简,分析了简化阻尼阻抗接口和理想变压器接口的稳定性。分析了简化阻尼阻抗接口对数字仿真系统精确性的影响,得出在阻抗匹配时阻尼阻抗法不受接口延迟影响的透明特性。针对物理模拟系统无源和有源2种情况,分析了简化阻尼阻抗接口和理想变压器接口对物理被试系统精确性的影响,得出理想变压器接口带有源负载能力优于阻尼阻抗接口的结论。根据理论分析结果,给出了在各种情况下选择接口算法的原则。

功率连接型数字物理混合仿真系统(二)适应有源被试系统的新型接口算法

将实时数字仿真技术和动态物理模拟技术结合起来,可以对含可再生能源和储能的微网系统进行研究与测试。由于被试系统为有源系统,对混合仿真系统的接口算法提出了更高的要求。针对简化阻尼阻抗接口,设计了一种适用于有源被试系统的阻抗跟踪算法,实现了实时阻抗匹配。提出了一种新的混合接口模型,新接口用理想变压器接口构成前向驱动器,以激励物理模拟系统;由简化阻尼阻抗接口构成反向观测器,以获得精确的数字仿真结果。MATLAB仿真表明,对于有源被试系统,新接口算法兼顾了简化阻尼接口算法对数字仿真系统的"透明性"以及理想变压器接口的带有源负载能力。

功率连接型数模混合仿真系统接口特性分析

为解决功率连接型数模混合仿真中闭环稳定性与仿真精确性两个关键问题,提出基于系统传递函数的稳定性分析方法和精确性评估方法。介绍并比较了5种接口算法的特性,研究论证了其稳定性与精确性的优劣。在Matlab/Simulink中搭建了简单电路数字仿真子系统与物理被试系统的模型,对5种接口算法的稳定性与精确性进行了离线仿真,结果表明特定应用中阻尼阻抗法相比于其他算法可行性更高。

结晶器出钢拉速系统的SIMULINK优化实现

PID或PI控制器参数之间的匹配关系,一直是PID控制算法所研究的问题。该文提出了一种基于SIMULINK,借助于最小平方优化函数lsqnonlin,遵循ItAE积分准则,针对于像结晶器出钢拉速的动态扰动,多变结构系统的PID或PI控制器参数优化方法。仿真与现场分析表明了该方法简捷、实效、可靠。除此之外,还就PID控制,SIMULINK仿真,ItAE积分准则,交流矢量电机控制模型等涉及到PID参数优化等问题进行简要的讨论。

实时倒立摆系统的设计与实现

为了克服商业倒立摆存在通用性差,不便于改装升级,不利于新的控制算法探索和研究等问题,一种实时倒立摆系统被设计和实现。系统硬件采用PC机+运动控制器方式;软件采用Real-Time Windows Target方式,使用SIMULINKC MEX S函数在PC机上开发了设备驱动模块,并通驱动模块构成实时倒立摆控制系统。实验结果表明,该系统通用性能高,倒立摆系统的软件和硬件参数完全已知,无任何加密或者固化,便于改装和升级,也方便算法研究者进行算法设计和实现。

JUNCTION BETWEEN GANJIANG FAULT AND TANLU FAULT AND ITS SIGNIFICANCE TO MINERALIZATION

The concept of fault junction is proposed to describe the relationship between the two faults by the authors. The junction relationship between Ganjiang and Tanlu faults is analyzed in this paper, and this has been elucidated through numerical simulation about the tectonic stress field analysis. Numerical simulation of the tectonic stress field conducted for the major mineralization stage of the Jiujiang-Ruichang junction area reveals that the stress field of the junction structure at the major mineralization stage shows a relatively close relationship with the formation of the ore deposits (occurrences).

Epidemic Spreading Model Based on Social Active Degree in Social Networks

In this paper,an improved Susceptible-Infected-Susceptible(SIS) epidemic spreading model is proposed in order to provide a theoretical method to analyze and predict the spreading of diseases.This model is based on the following ideas:in social networks,the contact probability between nodes is decided by their social distances and their active degrees.The contact probability of two indirectly connected nodes is decided by the shortest path between them.Theoretical analysis and simulation experiment were conducted to evaluate the performance of this improved model.Because the proposed model is independent of the network structure,simulation experiments were done in several kinds of networks,namely the ER network,the random regular network,the WS small world network,and the BA scale-free network,in order to study the influences of certain factors have on the epidemic spreading,such as the social contact active degree,the network structure,the average degree,etc.This improved model provides an idea for studying the spreading rule of computer virus,attitudes,fashion styles and public opinions in social networks.

Design and implementation of a SPMD simulation platform

This paper describes the design and implementation of HITASE, a general-purpose architecture Simulation Environment for evaluating performance of parallel machine architecture. This simulation environment is designed for SPMD parallel machines and implemented by using program-driven methodology. Compared to other similar simulation systems, our simulation environment has strong generalities, and can study new architecture, such as a reconfigurable multistage interconnection network.

Precise simulation of surface acoustic wave devices using frequency-dependent coupling-of-modes parameters

Herein we extract all the frequency-dependent coupling-of-modes （COM） parameters, which will be used to the rapid simulation and optimal design of surface acoustic wave （SAW） devices. FEM/BEM is used to calculate the exact field distributions of forward and backward surface acoustic waves within a finite-length periodic grating at every frequency. The middle compo- nent of the grating, regarded as a periodic structure, is selected to be investigated which can satisfy the presupposition of the COM model. From these field distributions, the values of P-matrix elements of one cell are calculated. The COM parameters taken as functions of frequency are accurately obtained. Specifically, the frequency-dependent relationships of reflection coefficient and propagation velocity are obtained independently. Using the resultant COM parameters, a one-port resonator on the substrate of 128°YX-LiNbO3 is simulated and the admittance curve shows good agreement with the simulating results using FEM/BEM. These results verify the validity and accuracy of this method.