蒸汽管网实时数据采集与计算机模拟优化系统

在现有蒸汽管网实时数据采集系统的基础上，利用计算机技术建立蒸汽管网模拟与优化系统，通过该系统能在线监测整个管网系统，以保证蒸汽管网优化运行。     

SAGCM-APD增益影响因子分析与优化

应用二维漂移扩散模型研究具有分立吸收层、渐变层、电荷层和倍增层结构(SAGCM)的InGaAsP-InP雪崩光电探测器(APD),仿真分析了不同电荷层、倍增层厚度和掺杂浓度对电场分布、电流响应及击穿电压的影响,特别是参数变量对增益计算模型的影响,载流子传输过程的时间依赖关系和倍增层中所处位置的影响,仿真结果表明:较高掺杂浓度和较薄电荷层结构可以改变器件内部的电场分布,进而提高增益值.当入射光波长为1.55μm,光功率为500 W/m2时,光电流响应量级在10-2A;阈值电压降低到10V以下,击穿电压为42.6V时,器件倍增增益值大于100.     

永磁同步电机变频调速 矢量控制系统的研究和仿真分析

以电压空间矢量控制的基本原理和概念为基础,结合Matlab/simulink软件包构建了永磁同步电机变频调速矢量控制系统的仿真模型,并详细给出各模型的具体参数。仿真结果显示,该方法简单,控制精度高,用于永磁同步电动机变频调速系统中具有良好动、静态性能。     

人字形板式换热器板片结构参数对流动型式的影响分析

建立了人字形板式换热器换热区液-液换热的三维稳态流场模型,得到不同结构参数下板间流体的三维流线图,通过观察不同板片结构参数下流体的流线走向来研究板片结构参数对人字形板式换热器板间流体流动型式的影响,得到了板间流体随板片结构参数的变化规律,为板式换热器设计和性能优化提供参考。     

Roughness of amorphous/crystalline interface in pre-amorphization implantation: Molecular dynamic simulation and modeling

Pre-amorphization implantation has been applied as a shallow junction technology. Roughness at amorphous/crystalline (a/c) interface should be controlled to improve junction characteristics. To understand and model a/c interface roughness, molecular dynamic method is applied in simulating pre-amorphization implantation. A method to reproduce roughness at a/c interface by molecular dynamic simulation is presented. A model of interface roughness is presented. Si and Ge implantation from 2-20 keV at a dose of 1 × 10¹⁵ cm⁻² is simulated. The depth of a/c interface is reproduced. Experimental results of a/c interface roughness are successfully simulated. The interface roughness is well reproduced and interpreted by the model presented.     

同步电机气隙磁场定向控制系统的仿真研究

文章根据矢量控制的基本原理，基于MATLAB/SIMULINK构造了同步电机气隙磁场定向控制系统的仿真模型。通过仿真试验验证了模型的正确性，并分析验证了文中所建立的调速系统具有良好的调速性能和抗扰动性能。     

数字滤波器仿真软件评估的谱分析方法研究

本文讨论了仿真模型验证常用的技术方法,针对数字滤波器仿真软件的特点,提出了采用谱分析的方法进行可信性评估.以双线性变换法设计的IIR数字滤波器仿真软件的可信性评估为例,应用Matlab软件分别采用程序设计法、基于SPTool的频谱分析方法和基于Simulink的频谱分析方法实现了对数字滤波器仿真软件滤波结果的频谱分析.     

High-voltage and low specific on-resistance power UMOSFET using P and N type columns

For the first time, we present the unique features exhibited by power 4H–SiC UMOSFET in which N and P type columns (NPC) in the drift region are incorporated to improve the breakdown voltage, the specific on-resistance, and the total lateral cell pitch. The P-type column creates a potential barrier in the drift region of the proposed structure for increasing the breakdown voltage and the N-type column reduces the specific on-resistance. Also, the JFET effects reduce and so the total lateral cell pitch will decrease. In the NPC-UMOSFET, the electric field crowding reduces due to the created potential barrier by the NPC regions and causes more uniform electric field distribution in the structure. Using two dimensional simulations, the breakdown voltage and the specific on-resistance of the proposed structure are investigated for the columns parameters in comparison with a conventional UMOSFET (C-UMOSFET) and an accumulation layer UMOSFET (AL-UMOSFET) structures. For the NPC-UMOSFET with 10 µm drift region length the maximum breakdown voltage of 1274 V is obtained, while at the same drift region length, the maximum breakdown voltages of the C-UMOSFET and the AL-UMOSFET structures are 534 and 703 V, respectively. Moreover, the proposed structure exhibits a superior specific on-resistance (R_on,sp) of 2 mΩ cm², which shows that the on-resistance of the optimized NPC-UMOSFET are decreased by 56% and 58% in comparison with the C-UMOSFET and the AL-UMOSFET, respectively.     

VLSI的计算机模拟模型研究

本文回顾了器件模型的发展历程,分析了在电路模拟中广泛使用的SPICE Leve13模型的器件输入、输出、衬偏、亚阈值等特性,指出该模型在模拟小尺寸器件时的不足之处,详细分析了影响MOS器件特性的主要小尺寸效应：自顾不暇 、窄沟道效应、非均匀掺杂效应、迁移率衰减效应、速度饱和效应、漏感应势垒降低效应、热电子效应、亚阈值电导等物理机理以及对器件性能的影响,分析了建立在上述多种效应基础之上的小尺寸器件的BSIM模型的机理（Berkley Short Channel IGFET Model）。     

一类新型 PWM 可逆整流器

针对传统的桥式ＰＷＭ可逆整流器直流侧工作电压要求较高的限制,提出一种新型ＰＷＭ可逆整流器拓扑,运用状态空间平均法进行了建模和稳态理论分析,并给出该变流器的参数选择方法。ＭＡＴＬＡＢ数值仿真与样机实验结果证实了该拓扑、模型及理论的正确性。