基于粒子群算法的APF直流侧电压控制

直流侧电压的的控制影响到有源电力滤波器(APF)的功率损耗和补偿性能,以三相三线制APF为研究对象,推导APF电压环传递函数为被控对象,构造简化定常系统和加入时变环节的时变系统。针对传统PI控制参数难整定、时变系统适应性差的问题,将引入收缩因子和惯性权重线性递减的粒子群算法(PSO)纳入到PI参数的优化中,合成离线PSO-PI控制和在线PSO-PI控制。仿真表明,较传统PI控制,在线PSO-PI控制对时变系统具有超调量小、响应快、适应性强的特点。     

混沌开关电源输出端有源滤波器的设计

混沌扩频技术是从源头上改善高频开关电源EMC特性的一种有效方法,但同时开关电源输出电压的纹波会随频率调制系数的增大而有所增加.为使输出电压的纹波降低到原来的水准,本文在开关电源的输出端增加一个简单的有源滤波器.这个有源滤波器结构简单、成本低、体积小、对开关电源输出电压的动态特性影响不大.本文主要阐述这个有源滤波器的设计.     

基于无差拍SVPWM的有源滤波器研究

采用无差拍电压空间矢量控制法来分析有源滤波器的滤波性能,给出该方法的控制策略,包括空间矢量脉宽调制（SVPWM）算法以及无差拍原理。该方法可以用来抑制和消除采样与计算方法的延时对控制精度的影响。Matlab仿真结果表明：SVPWM调制与无差拍控制结合用于有源滤波控制可以明显改进补偿的动态性能,提高滤波效果。实验结果证明该方法可行,且具有较好的实时性。     

Control techniques for a high power factor multilevel rectifier based on double boost converter

In this paper three novel control schemes for the single-phase ac/dc converter with two-level or three-level pulse width modulation are proposed to improve the power quality. A diode rectifier with two power switches is adopted as a power factor correction circuit to achieve high power factor and low harmonic distortion. The proposed control schemes are based on look-up tables with a hysteresis current controller instead of the conventional complex control algorithm. The proposed control scheme can (1) draw a sinusoidal line current, (2) achieve a unity power factor and (3) improve voltage unbalance problem on the dc bus capacitors. The software simulations and experimental results are shown to verify the proposed control algorithms. It is shown that the measured harmonic currents and input power factor satisfy the international standard requirements such as International Electrotechnical Commission 1000-3-2.     

基于LT1568的高频段有源滤波器的设计

对于高频信号,传统的由分立元件搭建的LC无源滤波网络,设计过程复杂,对信号衰减较大。为了简化高频段滤波器的设计过程、提高滤波效率,提出了使用低噪声高频有源RC滤波芯片LT1568来设计高频滤波电路,介绍其性能,分析了其工作原理。并以高频多普勒接收机内部带通滤波器设计为例,介绍滤波电路的设计方法。实验仿真表明用其搭建的高频有源滤波电路滤波效果明显、电路简单、方便易用。     

基于间谐波检测的有源滤波器设计

配电网中的间谐波是引起电压闪变的重要原因。针对上述问题,设计了基于巴特沃斯滤波器的并联型有源滤波器,并以上海某港口配电系统的谐波状况为实例进行了仿真研究。仿真结果表明:该有源滤波器能够较好的滤除电网中的间谐波电流,抑制电压闪变。证明了该方案合理,有效。     

A novel DC voltage control strategy of series hybrid active power filter

In this article, a novel DC voltage control strategy which is independent of the detection of the primary winding voltage across the series transformer is proposed to solve the DC voltage control problem of the series hybrid active power filter (APF). Meanwhile, this proposed DC voltage control method adopts an open-loop control strategy. The inverter generates unchanged DC voltage control current to ensure that the fundamental voltage loss of the series transformer remain stable. The simulation and experimental results validity and feasibility of the proposed DC voltage control the method of the series hybrid APF.     

Dual sepic PWM switching-mode DC/DC power converter

A steady-state analysis and experimental results for a dual sepic pulse-width-modulated (PWM) DC/DC power converter for both continuous and discontinuous modes of operation are presented. The converter is dual to a sepic converter, but it can also be derived from a forward converter by replacing one of its rectifier diodes with a coupling capacitor. The circuit acts as a step-down or step-up converter, depending on the value of the ON switch duty cycle. The transformerless version of the converter has a positive DC/DC voltage transfer function. Therefore, the circuit is suitable for distributed power systems. Design equations for all circuit components are derived. Experimental results measured at 100 kHz were in good agreement with theoretical predictions     

Quasi current resonant DC link AC/AC converter

A new quasi current resonant DC link (QCRDCL) topology has been developed in this paper. Although prototype current resonant DC link topologies for AC/AC power conversion have had such problems as irregular high current peaks, uncontrollable pulse width, etc., this new topology enables the AC/AC conversion system to have the properties wherein the current peak is limited and the pulse width is adjustable. The system begins to assume an adjustable-width flat-topped current shape, whereby the system becomes particularly suitable for high power application. With control of the pulse width a very fine load current regulation can be obtained. In this system, an open loop PWM control has been adopted and almost the same quality of output waveforms as the conventional current source inverter has been achieved     

A series active power filter based on a sinusoidalcurrent-controlled voltage-source inverter

A series active power filter working as a sinusoidal current source, in-phase with the mains voltage, has been developed and tested. The amplitude of the fundamental current in the series filter is controlled through the error signal generated between the load voltage and a pre-established reference. The control allows an effective correction of power factor, harmonic distortion and load voltage regulation. Compared with previous methods of control developed for series active filters, this method is simpler to implement because it is only required to generate a sinusoidal current, in-phase with the mains voltage, the amplitude of which is controlled through the error in the load voltage. The proposed system has been studied analytically and tested using computer simulations and experiments. In the experiments, it has been verified that the filter keeps the line current almost sinusoidal and in-phase with the line voltage supply. It also responds very quickly under sudden changes in load conditions, reaching its steady-state in about two cycles of the fundamental     

Advanced power semiconductors and ICs for DC/DC converter applications

This paper describes recent advances in power semiconductor devices, integrated circuits, and packages for DC/DC converter applications. Special emphasis is placed on the latest discrete power MOSFET devices and packages. Features and trends in ICs for control of synchronous buck converters are highlighted as well. The paper will also cover a new class of miniaturized hybrid assembly that sets new efficiency standards for high current low output voltage applications.     

A versatile power converter for high-frequency link systems

A single-phase high-frequency link appears to be an attractive alternative to the DC link commonly used in power conversion systems. The authors propose a power converter suitable for one-step conversion of the single-phase high-frequency link voltage to the three-phase low-frequency voltages typically required for interfacing with system sources and loads. The converter utilizes zero voltage switching principles to minimize switching losses and uses an easy-to-implement technique of pulse density modulation for the control of the amplitude, frequency, and waveshape of the synthesized low-frequency signals. Adaptation of the proposed topology for power conversion to single-phase AC and DC voltage or current outputs is shown to be straightforward. The feasibility of the proposed power circuit and the control technique have been experimentally verified     

PCB integrated inductors for low power DC/DC converter

This paper discusses the use of printed circuit board (PCB) integrated inductors for low power DC/DC buck converters. Coreless, magnetic plates and closed core structures are compared in terms of achievable inductance, power handling and efficiency in a footprint of 10 /spl times/ 10 mm/sup 2/. The magnetic layers consist of electroplated NiFe, so that the process is fully compatible with standard PCB process. Analytic and finite element method (FEM) methods are applied to predict inductor performance for typical current waveforms encountered in a buck converter. Conventional magnetic design procedures are applied to define optimum winding and core structures for typical inductor specifications. A 4.7 /spl mu/H PCB integrated inductor with dc current handling of up to 500 mA is presented. This inductor is employed in a 1.5 W buck converter using a commercial control integrated circuit (IC). The footprint of the entire converter measures 10 /spl times/ 10 mm/sup 2/ and is built on top of the integrated inductor to demonstrate the concept of integrated passives in power electronic circuits to achieve ultra flat and compact converter solutions.     

A single-phase capacitor clamped converter operated simultaneously as a PWM rectifier and an active power filter

A control scheme is proposed that employs an active rectifier to work simultaneously as an active power filter to decrease current harmonics. The adopted capacitor clamped rectifier is controlled to draw a sine wave line current with low current harmonics. A voltage controller, three capacitor voltage compensators and one current controller are used in the proposed control algorithm to achieve a constant DC bus voltage, balanced capacitor voltages and line current tracking. The validity of the proposed system is proved by the results of computer simulations and experimental tests.     

级联型有源电力滤波器的研究

把级联型变流器应用于有源滤波装置是实现大容量谐波补偿的重要途径。介绍级联型有源电力滤波器的基本原理,针对级联型拓扑结构基于瞬时无功功率理论改进了指令电流的计算,使其三相直流侧电压独立控制,满足有源电力滤波器运时对直流侧电压稳定性的要求。用载波相移—正弦脉宽调制(CPS-SPWM)实现电流跟踪控制,并对CPS-SPWM进行了数学分析,同时为了降低启动过程中直流侧电压和电流的过冲,设计一种直流侧预充电方案。最后通过仿真软件MATLAB/Simulink进行仿真验证设计可行性。     

A novel active power filter based on the least compensation currentcontrol method

A new least compensation current technique to detect the harmonic and reactive current for active power filters is presented in this paper. With the technique, a novel active power filter based on the least compensated current control is proposed, in which the measurement of harmonic and reactive current and the generation of compensated current are completed in the same closed-loop. Compared with the existing control methods of active power filter, the proposed method has simpler structure, quicker dynamic, higher reliability and better compensation performance. Simulating and experimental results are provided that verified theoretical predictions and demonstrate the effectiveness of the proposed control method and circuit configuration     

A novel shunt hybrid active power filter based on magnetic flux compensation

In this article, the principle of a novel shunt hybrid active power filter (APF) based on magnetic flux compensation is proposed. The parallel transformer can exhibit nearly zero impedance to harmonic current whereas the zero magnetic flux condition is satisfied for harmonics, which leads harmonic current to flow into the transformer branch. Meanwhile, the transformer can exhibit continuously adjustable impedance to the fundamental current based on fundamental magnetic flux compensation, which works together with the passive power filter to compensate for reactive power. A mathematical model is established for system stability analysis and steady state estimation. The experimental results verify that the performance of the proposed APF is satisfactory in harmonic suppression as well as reactive power compensation.     

基于滑模控制的三相四线制有源滤波器的研究

为了实现三相四线制系统中有源滤波器电流跟踪控制的快速性和鲁棒性．提出了一种基于滑模控制的有源滤波器。在d-q-0坐标系中建立三相四线有源滤波器的数学模型,通过逆系统的方法实现解耦和线性化,并对滑模控制的趋近律进行改进以削弱抖振、加快跟踪速率。仿真结果表明,采用滑模控制实现指令电流跟踪的有源滤波系统鲁棒性强、快速性好、跟踪误差低,总体性能得到明显提升。     

模块化多电平静止无功补偿器控制策略研究

随着多电平逆变器在电力系统无功功率补偿领域的广泛应用,提出了一种基于模块化多电平( MMC)技术的新型静止无功补偿器( STATCOM)的拓扑结构。该拓扑结构具有模块化程度高、可靠性好、便于维护及容量拓展等特点,是一种极具发展潜力的拓扑结构。首先对MMC-STATCOM的工作原理和数学模型进行了分析,提出了无功功率解耦控制策略以及提出了一种新的控制子模块电容电压平衡的控制算法。仿真和测试结果均表明MMC-STATCOM具有补偿效果好,动态响应速度快等优点,是一种具有工程应用价值的大容量STATCOM主电路拓扑。     

A novel ZVS DC/DC converter for high power applications

This paper presents a novel zero voltage switch (ZVS) pulse-width modulation (PWM) DC/DC converter for high power, high output voltage applications. By using two active switches in the secondary side of a transformer, the proposed converter achieves not only ZVS of the active switches in the entire load ranges but also soft commutation of the output rectifier diodes. The proposed topology has simple structure and control strategy. Simulation results and experimental results of a 2.8 kW 200 kHz DC/DC converter are presented.