网侧PWM整流器LCL输出滤波器优化设计

提出一种网侧PWM整流器LCL滤波器的参数设计方法,通过对LCL滤波器单相模型传递函数的研究,得到谐振频率、谐波电流幅值衰减比与r（网侧电感与整流器侧电感的比例因子）之间的关系式。利用关系式分析各变量的变化规律,确定总电感值、滤波电容值和r。分析结果表明,谐振频率可确定总电感和滤波电容的下限值。给出了一个设计实例,进行系统建模仿真验证。仿真对比结果证明了该设计方法的正确性和优越性。     

三相高功率因数可逆变流器的主电路参数设计

高功率因数变流器可对输入电流进行实时控制,使系统具有高功率因数,低谐波含量,改变装置中的有功和无功电流,因此可显著提高输电系统传输功率的能力。本文主要阐述该变流器的主电路参数即交流侧电感和直流侧电容在系统中的核心作用,从系统稳定性、电感及电容与功率因数的关系等方面考虑,给出了主电路参数的设计思想以及设计方法。通过仿真分析验证了主电路参数设计的正确性。     

一种新的低压大电流DC-DC变换器的研究

该文比较了低压大电流DC-DC变换器各种拓扑结构的优缺点，对称半桥一倍流整流对于48V的输入电压是一种合适的拓扑结构。它可以通过两个滤波电感纹波电流的叠加，极大地减小滤波电容上的纹波电流。从而可以减小滤波电感的值。而且在滤波电容旁串联一个电感，可以极大地发挥它的作用，将滤波电容上的纹波电流进一步减小。给出了电路的仿真模型，并使用PSpice对该模型进行仿真，最后得到的仿真结果同理论分析一致，取得满意效果。     

带CLC滤波的双管反激四阶小信号模型

普通双管反激变换器的输出端只有一级电容滤波,存在着电流纹波大、稳定性差、精度低等缺点。为克服上述缺点,在这种变换器的输出端增加了一级电感-电容（LC）滤波器,构成了输出端带有电容-电感-电容（CLC）滤波的新型变换器,并应用状态空间平均法确定了电路的静态工作点,推导出该变换器的动态四阶小信号模型。应用该模型设计了一个实际变换器,并通过分析该变换器的波特图给出系统补偿网络参数,利用MATLAB仿真以及实验验证了该四阶小信号模型的正确性。     

电脑的第一道保护 电源的EMI滤波电路

相信很多读者朋友也都注意到了,在电源评测文章中,作者大多喜欢通过EMI滤波电路的做工用料来判断电源的品质,这说明EMI滤波电路是非常重要的。那么,到底EMI滤波电路对电源品质的提高有什么好处呢？普通消费者如何通过这一电路来看电源的品质呢？     

基于PCB平面线圈的电动球阀手动扳手检测电路设计

该文提出了新的基于PCB(printed circuit board)平面线圈的电动球阀手动扳手检测方案，计算了不同线宽、间距、匝数等参数PCB线圈的总电感量、串联电阻等参数，并制作了双层PCB平面线圈，设计了电容三点式LC振荡电路、幅度检波电路。测试结果表明，手动扳手插入后，LC振荡波形的幅度有明显的减小，其电压峰峰值由2.24 V减小到1.28 V，检波电路输出电平幅度由0.64 V增大到2.76 V，能够满足实际测量的要求。     

新型脉冲电源等效电路动态特性研究

研究电感储能的新型脉冲电源提高效能问题,采用脉冲电容储能型电源,制造复杂。采用开关控制,限制了发展,同时由于给出了脉冲电源的等效电路并导出电路对应的变系数微分方程,方程的解析求解较为复杂。为解决上述问题,建立了电感储能型等效电路的模型,进行仿真,结果明确了电路各元件参数对输出脉冲特性的影响,验证了计算结果的可靠性。研究电感储能型脉冲电源电路参数的取值对输出脉冲电压的特性有着较明显的控制效果,通过适当选择各元件参数的取值,可以获得较小脉冲电压脉宽的同时又有较高的电压幅度。仿真结果为新型脉冲电源系统设计过程中参数的选择提供了可靠的依据。     

基于风洞的电容式加速度计检测电路设计

针对风洞试验中的振动,设计了变面积式电容式加速度传感器,阐述了弱信号检测系统并着重介绍了几个重要的模块电路即交流激励信号源电路、电容电压电路、滤波电路、并利用电子自动化检测仿真软件multisim对设计的主要模块电路分别进行了仿真分析。仿真结果表明设计的电路能完成微弱电容信号的检测。同时,为了提高电路性能,对弱信号检测电路中的杂散电容干扰进行了分析研究,并设计了电路对噪声进行了抑制。     

数字电路板EMI的短时分形维数模糊控制滤波

基于短时分形维数的模糊控制滤波方法,对数字印制电路板(PCB)电磁干扰(EMI)信号中的噪声进行滤波;该方法提出了网络分形维数和短时分形维数的新算法,并讨论了模糊控制滤波方法中的模糊控制参数的选取算法;基于虚拟仪器(VI)LabVIEW6.i平台上对数字印制电路板传导干扰信号进行实时检测;经过信号处理,该系统还具有信噪分离、测量传导干扰信号的功率谱等功能;结果表明,该方法滤波效果良好.     

开关电容滤波器混叠效应仿真及抑制

在模拟信号调理过程中,模拟信号的滤波电路是硬件设计的关键。普通的低阶有源滤波电路无法满足传感器信号滤波电路对衰减率的要求,高阶集成开关电容滤波芯片能够实现高精度、稳定的滤波特性,但由于开关电容滤波芯片具有采样特性,不可避免地会出现混叠现象。通过对滤波芯片混叠效应的理论分析,定量地计算出后续二阶压控低通滤波电路的截止频率。实验证明,该方法能够有效抑制开关电容滤波电路出现的混叠效应。     

Dual‐band differential bandpass filter using stepped impedance resonators

In this article, a novel dual‐band differential bandpass filter using (SIRs) is designed. To demonstrate the design ideas, the differential and common mode equivalent half circuits are built and studied. Two resistors are connected between the two ends of the SIRs to consume the power in common mode. A capacitor is connected between the Ground and Center of the SIR to adjust the spurious frequencies, also strength the coupling of the two SIRs. The theoretical analysis shows the second band can be obtained by the proper impedance ratios of the resonances and the capacitor connected to the resonator. Two through ground vias (TGVs) connecting the top and bottom sides of the SIR filter, are used to realize the common mode rejection. To investigate the proposed filter in detail, a set of design equations are derived based on the circuit theory and transmission line theory. A phototype dual‐band differential filter operating at 1.5 and 2.75 GHz has been realized to validate the proposed concept and theory. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:468–473, 2015.     

Versatile energy recovery circuit for driving AC plasma display panel with single sustain circuit board

This paper presents an energy recovery (ER) circuit which can operate either in a series or a parallel resonance mode and can drive an AC plasma display panel (PDP) with a single sustain circuit board. The proposed ER circuit consists of one energy storage capacitor, two energy recovery inductors, and three insulated-gate bipolar transistors. The circuit operations in the series and parallel resonance modes are similar to conventional ones, except for the leading edge of the first sustain pulse and the trailing edge of the last sustain pulse. To reduce power consumption in the parallel resonance mode of operation, these two pulse edges are generated using a series resonance between the panel capacitance and the energy recovery inductor. The proposed circuit had energy recovery efficiencies in both the series and parallel resonance modes that were nearly the same as the efficiency of the conventional series resonance ER circuit. Experimental results on a 42-inch XGA single-scan PDP show that the proposed ER circuit is suitable for use in a PDP drive circuit.     

高功率低通滤波器的设计

高功率低通滤波器是微波电路中的关键部件。介绍了高功率低通滤波器的设计新方法,对滤波器中的关键元件电感的设计进行了详细的描述,并且对电容进行了热设计分析。电容的设计思想来源于微带高低阻抗线低通滤波器和集中参数低通滤波器,实现方便,与高低阻抗线低通滤波器相比,可以承受更高的功率容量,最后进行了实例性能测试,与测试电性能指标一致,并且满足功率容量的要求,通过相关试验证明了该设计的可行性。     

基于低温共烧陶瓷的无线无源传感器设计

设计一种基于低温共烧陶瓷(LTCC)的无线无源压力传感器。电感器和电容器并联组成的LC谐振回路构成传感器的工作电路,采用厚膜工艺完成了平面螺旋电感器和平行板电容器的制备。传感器利用LC谐振回路的谐振频率对不同压力的响应来表征传感器的应变特性,采用2个电感耦合的方式来实现无线检测。测试结果显示:传感器的谐振频率随外加压力的增大而减小,其谐振频率变化对压力的响应灵敏度约为331.70 kHz/bar。     

New improved two-phase interleaved converter with clamp circuit and diode capacitor cell

This paper introduces a new improved two-phase DC–DC interleaved converter with clamp circuit and diode capacitor cell with coupled inductor for DC micro grid. The key focus of this research is to amend voltage gain and to cut down the stress of the switches. The diode capacitor arrangement with coupled inductor used to attain twice the voltage gain. The capacitors are connected end to end at the output to dismiss the voltage ripple. The gain of the modified converter is improved by secondary winding of coupled inductor. The leakage energy of the inductance is recycled and voltage spikes of power switches during turn off operation are suppressed by clamp circuit. The theoretical analysis of the modified converter is verified through simulation. A prototype of 150 W is constructed to demonstrate the efficient operation of the converter.     

A printed circuit board capacitive sensor for air bubble inside fluidic flow detection

This paper presents a three-electrode capacitive fluidic sensor for detecting an air bubble inside a fluidic channel such as blood vessels, oil or medical liquid channels. The capacitor is designed and fabricated based on a printed circuit board (PCB). The electrodes are fabricated by using copper via structure through top to bottom surface of the PCB. A plastic pipe is layout through the capacitive sensor and perpendicular to the PCB surface. Capacitance of sensor changes when an air bubble inside fluidic flow cross the sensor. The capacitance change can be monitored by using a differential capacitive amplifier, a lock-in amplifier, filter and an NI acquisition card. Signal is processed and calculated on a computer. Air bubble inside the liquid flow are detected by monitor the unbalance signal between the three electrode potential voltages. Output voltage depends on the volume of the air bubble due to dielectric change between capacitor’s electrodes. Output voltage is up to 53 mV when an 2.28 mm³ air bubble crosses the sensing channel. Air bubble velocity can be estimated based on the output pulse signal. This proposed fluidic sensor can be used for void fraction detection in medical devices and systems; fluidic characterization; and water–gas, oil–water and oil–water–gas multiphase flows in petroleum technology. That structure also can apply to the micro-size for detecting in microfluidic to monitor and control changes in microfluidic channels.     

Automated passive filter synthesis using a novel tree representation and genetic programming

This paper proposes a novel tree representation which is suitable for the analysis of RLC (i.e., resistor, inductor, and capacitor) circuits. Genetic programming (GP) based on the tree representation is applied to passive filter synthesis problems. The GP is optimized and then incorporated into an algorithm which can automatically find parsimonious solutions without predetermining the number of the required circuit components. The experimental results show the proposed method is efficient in three aspects. First, the GP-evolved circuits are more parsimonious than those resulting from traditional design methods in many cases. Second, the proposed method is faster than previous work and can effectively generate parsimonious filters of very high order where conventional methods fail. Third, when the component values are restricted to a set of preferred values, the GP method can generate compliant solutions by means of novel circuit topology.     

基于目标轮廓几何特征的电容元件定位方法

随着印刷电路板(PCB)生产工艺愈加复杂,电容元件的定位识别难度也随之增加。在实际生产中,为了节约成本、减少出错率,需要在焊接之前对电路板进行检测,同时为了固定电路板上元器件,一般会使用压板固定电路板。针对此种情况,提出一种复杂背景下被遮盖电容元件的定位方法,通过对采集到的PCB图像进行预处理、阈值分割、边缘提取和Harris角点检测等操作,进而根据电容元件目标轮廓的几何特征对元件进行定位。该方法已经在实践中得到应用,定位准确率高、速度快,能广泛应用于实际生产中。     

低噪声硅微陀螺敏感电容电荷读出电路设计

硅微陀螺敏感电容电荷读出电路性能的优劣直接决定着陀螺仪测量精度.通过对敏感电容读出电路的建模分析,采用差分调制技术实现了低噪声信号输出,从电路组成、参数设置、PCB布局布线等多方面综合考虑,优化设计了能抑制低频噪声以及高灵敏度电荷读出电路.实验结果表明:该电路输出噪声为-116.24 dBV/√Hz,敏感电容检测分辨率可达1.16 ×10-19 F√Hz.     

新型ZCS-PWM Buck变换器的磁集成研究

研究新型ZCS-PWM Buck变换器,通过电感和电容的谐振使流过功率开关管的电流呈正弦波形,为开关管提供了零电流开关条件。提出将分立的谐振电感和滤波电感集成在同一个平面磁芯上。理论分析和仿真结果证明了该方案的正确性和可行性。