多路隔离输出全数字伺服系统开关电源设计

根据设计全数字永磁交流伺服系统的需要,使用Power Integration公司生产的开关电源专用集成芯片TOP224Y,设计了单端反激式多输出辅助开关电源。使用该芯片设计的小功率开关电源,可大大减少外围电路,降低成本,提高可靠性,同时,可以改善电源的电磁兼容性能。重点论述了开关电源的电路设计及高频变压器的设计。本辅助电源稍经改动也可以直接用在其他电机控制系统中。     

基于成对错误概率的空时编码性能分析

空时编码综合了空间分集和时间分集的优点，能够获得远大于单天线系统的频带利用率，从成对错误概率的角度出了，详细分析比较了现有3种时编码增益和分集增益，以及它们与频带利用率之间的关系，结果表明，分层空时码可以获得的频带利用率远大于其他两种空时码；但对分集增益而言，网络空时码和分组空时码均可达到系统所能提供的最大分集增益，而分层空时码由于受实现方式的制约，只能得到其中一部分分集增益。     

高效紧凑的高频地波雷达天线阵列设计

分析了高频地波雷达阵列单元天线和阵列的设计原理,提出并成功设计出了一套高效紧凑、一发八收、收发共用的高频地波海洋环境监测雷达天线阵列.计算机模拟和现场试验结果说明了本文设计方案的合理性.     

数字PWM方法的改进

数字化PWM调制在高频应用中存在精度受限制的问题，本文提出一种新的PWM技术——双调制PWM，结合高频和低频的优势，解决了数字化PWM中高频与精度之间的矛盾，使数字化PWM可用于高频、高精度电能变换器之中，理论分析、仿真和实验结果均论证了这一方法的优越性。     

一种便携式多功能测量仪

介绍用８０９８单片机为核心组成的便携式多功能测量仪。该仪器采用模块式插入技术实现了多功能测量，利用软件修正误差技术提高了仪器的测量准确度，使之具有较高的性能价格比，特别是高频电压实现了数字化测量，且通过频响误差修正达到了较高的准确度。该仪器的研制成功对设计制造具有中国特色的电子测量仪器有一定的参考价值。     

On a Modification of the PID Controller

In this article we propose a modification of the PID controller. Theexpression for static error for systems with a modified controller isderived. We have obtained the parametric equations describing the boundariesof the asymptotic stability domain in the space of feedback gains. Theasymptotic stability domain for the system of second order with modifiedcontroller is derived. Some numerical results and example arepresented.     

The Eigenvalue Problem for the 2D Laplacian in ℋ-Matrix Arithmetic and Application to the Heat and Wave Equation

A class of matrices (-matrices) has recently been introduced by Hackbusch for approximating large and fully populated matrices arising from FEM and BEM applications. These matrices are data-sparse and allow approximate matrix operations of almost linear complexity. In the present paper, we choose a special class of -matrices that provides a good approximation to the inverse of the discrete 2D Laplacian. For these 2D -matrices we study the blockwise recursive schemes for block triangular linear systems of equations and the Cholesky and LDL^T factorization in an approximate arithmetic of almost linear complexity. Using the LDL^T factorization we compute eigenpairs of the discrete 2D Laplacian in -matrix arithmetic by means of a so-called simultaneous iteration for computing invariant subspaces of non-Hermitian matrices due to Stewart. We apply the -matrix techniques to approximate the solutions of the high-frequency 2D wave equation for smooth initial data and the 2D heat equation for arbitrary initial data by spectral decomposition of the discrete 2D Laplacian in, up to logarithmic factors, optimal complexity.     

Covariance control with observed-state feedback gains for continuous nonlinear systems using T-S fuzzy models

The design problem of state variance constrained control for stochastic systems has received rather extensive attention in recent years. This paper solves the state variance constrained controller design problem by using the covariance control theory, with observed-state feedback gains for continuous Takagi-Sugeno (TS) fuzzy models. By incorporating the technique of state estimation into the practical covariance control theory, a variance constrained control methodology is developed for the continuous TS fuzzy models. Finally, a numerical example is shown to demonstrate the efficiency and applicability of the proposed approach.     

充电器大功率变压器的设计

介绍开关电源高频大功率变压器设计的材料选择、计算方法和过程,并给出了一个充电器大功率变压器的设计实例,实验证明该变压器符合实际要求。     

开关电源高频变压器电容效应建模与分析

该文分析了开关电源中高频变压器在考虑了变压器绕组导体的电位分布情况下的电场储能特性和共模电磁干扰发射特性。指出采用一端口入端电容描述电场储能效应，而采用二端口转移阻抗电容描述共模电磁干扰发射效应，并提出了相应的参数计算方法。在此基础上，建立了新的高频变压器电容效应模型，该模型可以同时兼顾变压器的电场能量储存特性和共模噪音抑制特性，能合理地揭示变压器内共模噪音电流的流动机理。实验和仿真结果均验证了理论分析和模型。