自主均流高频开关电源的研究

由于大功率负载需求和分布式电源系统的发展，越来越多的电源系统采用模块并联技术。本文介绍了一种新型高频开关电源及220V／10A整流模块的实现。整流模块采用具有高可靠性的电流型PWM整流器及全桥变换电路，分别实现三相功率因数校正和DC／DC变换，模块间采用最大电流自动均流法(又叫自主均流法)实现自主均流。     

大功率IGBT模块并联均流特性研究

大功率IGBT并联运行能够承受更高的负载电流,但是大功率IGBT并联设计时需要考虑静、动态均流问题。PSpice仿真分析表明,影响静态均流的主要因素是IGBT模块的饱和导通压降和集电极、发射极引线的等值电阻;影响动态均流的主要因素涉及驱动电路、IGBT器件参数和主电路布局。提出了IGBT并联均流的措施,分析了IGBT并...     

基于改进主从法的并联双向直流电源系统控制

随着各种用电设备容量的增加,对大功率电源的需求日益迫切。由于大容量的单体电源技术尚不成熟,因此多电源模块并联运行技术成为解决当前实际需求的有效手段之一。对于并联直流电源系统,提出了一种电源模块基于主从控制的数字均流改进算法。该算法在主从控制的基础上,通过限制主模块最大输出电流、电路启动时主模块采用软启动控制等技术,使输出电压分段上升,降低了并联电源主从控制中主模块出现故障和系统瘫痪的概率。针对不同电源模块的电路特性,设定系统响应时间慢的电源模块为主模块,并且设置从模块PWM调节速率大于主模块,可以降低PID参数对于每个电源模块调节稳定性和均流精度的影响,减少实际PID参数调试时间。实验结果表明,改进的算法可以实现较好的系统稳定性且均流精度高,均流误差低于1.5%,而且硬件电路设计简单。     

基于单片机的电流比任意可调并联电源设计与实现

开关电源并联系统中往往存在两个并联电源性能参数不同甚至差异较大的情况,因此不能采用传统的并联均流方案来平均分摊电流,这就需要按各个电源模块的输出能力分担输出功率。基于这种灵活性的需要,本设计在采用主从设置法设计并联均流开关电源的基础上新增加了单片机控制模块,实现了分流比可任意调节、各模块电流可实时监控的半智能化并联开关电源系统。实测结果表明,该并联开关电源系统分流比设置误差小于0.5%,具有总过流和单路过流保护功能。     

并联变换器均流控制策略研究

将模糊控制引入并联变换器均流控制技术中,对模糊控制规则以及选择模糊控制器输入变量的量化因子和输出控制量的比例因子进行了分析。提出了一种按中间电流自主均流方法。该方法减小了各相电流调节幅度,使得各相电流很快均衡。仿真实验结果表明,均流控制策略能够使得并联变换器具有良好的动态均流与负载均分特性,能够在大负载变化内良好运行。     

DC/DC变换器平均电流自动均流并联控制的研究

采用三环控制策略,其中电流环为内环,电压环和均流环并行为外环,且反馈量是输出电流与输出电压,可将功率电路视为黑匣子,方便了各模块样机的并联;最后以并联Buck变换器为研究对象,设计了各环补偿网络,且对系统进行了稳定性分析。仿真结果表明,系统的动态响应与稳定性均达到要求,抗干扰能力强,且均流效果良好。     

并联IGBT动态均流分析

在我公司许多泵站大功率输油泵电机应用了基于IGBT变频装置的场合,有时需要对IGBT并联使用,本文对于影响IGBT并联静态均流和动态均流的因素进行了分析,并使用Pspice软件对其进行了仿真,最后得出结论,并给出IGBT并联的措施。     

大功率APFC开关电源中的并联均流技术

本文在对APFC大功率高频开关电源研究的过程中,着重对开关管的并联均流技术进行了深入研究,并对一种新的并联均流技术进行了理论分析、模拟仿真,结合中功率(3KW)ZVT-APFC模块电路实验,探讨了这种并联均流技术应用在APFC电路中的设计方法.     

基于自主均流技术的功率因数校正电路的研究

针对现有的功率因数校正电源模块(PFC)直接并联后均流精度差的问题,提出一种基于自主均流技术的功率因数校正电路。该策略在电源模块的输出端引入负电压采样电路和自主均流电路,实现了功率因数校正电源模块的自动均流,提高了电源模块并联后的均流精度。基于Saber仿真软件搭建了基于自主均流技术的功率因数校正电路。仿真结果不仅验证了该电路的有效性,而且也表明了电源模块的均流精度在轻载并联时能控制在5%以内。     

静电除尘用大功率高频高压电源预测控制研究

静电除尘用大功率高频高压电源系统具有非线性、时变性、迟滞性等特点,需要一类数学模型要求低、自适应能力强的非线性控制方法;以自主研发的静电除尘用大功率高频高压电源为研究对象,基于现场实际电源系统试验结果,采用最小二乘法辨识系统的近似传递函数模型,最后设计了一种新颖的基于动态矩阵算法(DMC)的模型预测控制器,实现针对电源输出电压的控制;仿真结果表明,该算法具有稳定性好、自适应强等优点,并具有良好的控制效果。     

Nonlinear multivariable control of nuclear power plants based onthe unknown-but-bounded disturbance model

A nonlinear control system that is based entirely on the time-domain representation of dynamic systems is proposed for the control of a simplified pressurized-water-reactor (PWR) nuclear power plant model. The initial stage consists of designing several linear control systems using plant models linearized at preselected operating points. A set-theoretic algorithm is used that explicitly treats the control, control rate, and state constraints. The control objective is to design a system that uses only the available control, at the available rate, in the presence of an input disturbance, without violating the prespecified state constraints. The final stage of the design process uses the gain-scheduling technique to implement the linear control systems a global nonlinear control system. The final design is evaluated through transient response simulations using a simplified nonlinear model of a PWR-type nuclear power plant, with encouraging results     

基于VXI总线的雷达装备测试网络体系构建研究

雷达装备的发展对测试系统提出了越来越高的要求。本文对綦于VXI总线的雷达装备测试网络系统进行了研究。介绍了基于VXI虚拟仪器技术的雷达自动测试系统的硬件构成,通过对雷达测试测试需求的分析,阐述雷达装备测试网络系统的组成方案,对基于网络化方式的测控系统软件进行了设计。本文设计的系统对于雷达的综合测试具有借鉴意义。     

基于ADS的宽带微波功率放大器设计

宽带微波功率放大器在雷达和电子对抗中的应用越来越广泛,而宽带微波功率放大器的设计在国内还处于起 步阶段。本文采用实频技术方法和负载线仿真的方法设计了输入输出匹配电路,并使用先进的微波电路设计软件ADS 对电 路进行了优化和仿真,最终设计出一款X 波段宽带微波功率放大器。     

An improved Backstepping technique using sliding mode control for transient stability enhancement and voltage regulation of SMIB power system

The problem of transient stability and voltage regulation for a single machine infinite bus (SMIB) system is addressed in this paper. An improved Backstepping design method for transient stability enhancement and voltage regulation of power systems is discussed beginning with the classical Backstepping to designing the nonlinear excitation control of synchronous generator. Then a more refined version of this technique will be suggested incorporating the sliding mode control to enhance voltage regulation and transient stability. The proposed method is based on a standard third-order model of a synchronous generator connected to the grid (SMIB system). It is basically implemented on the excitation side of the synchronous generator and compared to the classical Backstepping controller as well as the conventional controllers which are the automatic voltage regulator and the power system stabiliser. Simulation results prove the effectiveness of the proposed method which ameliorates to a great extent the transient stability compared to the other methods.     

雷达模拟器中可视化仿真技术的实现

实验室要调试和验证雷达系统设计与雷达数据处理算法,雷达模拟器是必不可少的实物。雷达模拟器可仿真雷达的各种功能。为了实现这些功能进行可视化。针对模拟器可视化的要求,将MapObjects组件技术应用到雷达模拟器中,在VC环境下结合Windows编程技术具体实现了战场地理环境信息的建立,控制地理信息对象的设置与显示。建立想定目标运动仿真和雷达波位扫描等功能,能直观、准确、动态地表现雷达战场环境。仿真实验表明,雷达模拟器实现了目标运动和雷达数据处理算法的工作效果,为设计新型雷达提供可靠参考。     

Improving transient performance in tracking control for linear multivariable discrete-time systems with input saturation

In this paper, we present a composite nonlinear feedback (CNF) control technique for linear discrete-time multivariable systems with actuator saturation. The CNF control law serves to improve the transient performance of the closed-loop system by adding an additional nonlinear feedback. The linear feedback can be designed to yield a quick response at the initial stage, then the nonlinear feedback is introduced to smooth out overshoots when the system output approaches the target reference. As such, the resulting closed-loop system typically has very fast transient response and small overshoots. The goal of this work is to complete the theory for general discrete-time systems. The technique is applied to a magnetic-tape-drive servo system design and yields a huge improvement in settling time compared to that of a purely linear controller.     

雷达数字射频存储模块设计

在辐射式多目标雷达模拟测试系统中,研究了数字射频存储(DRFM)模块的设计,基于系统的设计要求提出一种新的数字射频存储模块设计方法;对数字射频存储模块的设计思路进行了详细阐述,分析了系统的设计方案以及各模块的功能,进行了设计结果的验证,验证表明所设计DRFM模块满足系统要求。     

A predictive current control method for shunt active filter with windowing based wavelet transform in harmonic detection

This paper has been established based on harmonic detection and compensation on power system. The present work deals with two powerful methods in harmonic detection field of digital signal processing. The first one is the windowing technique and the other one is wavelet transform. A traditional synchronous fundamental dq-frame algorithm is modified in filtering process. As an improvement, the Fourier-based low pass filter is replaced with a windowing–wavelet method. The adopted windowing aspect is Hamming window to reduce traditional rectangular window effete in frequency domain. In addition, the applied mother wavelet is selected in terms of its effectiveness on transient response, low overshot and low oscillation at frequency domain. Due to these concepts, the db8 is selected as mother wavelet. In harmonic elimination procedure, the detected harmonic is injected using a shunt active filter based on predictive current control technique. The presented method has been verified with MATLAB–SIMULINK model and wavelet toolbox. The results confirm that this method is superior to traditional FFT based and wavelet based filters because of fast transient response and small negligible sidelobes. As a consequence this technique is able to reduce power system harmonic.     

Switched control of frequency of interconnected power systems using variable structure†

This paper proposes a new technique based on eigenvalue assignment for the design of a variable structure load frequency controller for interconnected power systems. An important feature of the variable structure controller is that it can effectively improve the transient performance of the system while at the same time ensuring zero steady-state error. Further, when the variable structure system is operated in the so-called sliding mode, the response of the system becomes insensitive to plant parameter variations. The control problem is formulated and the results of a digital simulation study are presented for illustration. For comparison purposes, results obtained using a conventional integral controller and a linear optimal controller are also included.     

A duality principle for state estimation with partially noise-corrupted measurements. Volume 37, number 5, pp. 1039–1056

This paper deals with the design and evaluation of a variable-structure stabilizer (VSS) for a synchronous machine using variable-structure systems theory. The stabilizer design is based on a recently proposed geometric approach for finding out the switching hyperplanes for discontinuous control. The transient response of the variable-structure stabilizer is compared with those obtained using a power system stabilizer (PSS) based on a speed signal. The computer simulation results show that the VSS is more effective in improving system damping, transient stability and post-fault recovery of the terminal voltage. It is also shown that by operating the control system in a sliding mode, the performance of the controlled synchronous machine can be made insensitive to changes in the system parameters.