Transistor‐level optimization methodology for the complete design of switched‐capacitor filter circuits

This paper presents an automatic procedure for the design and optimization of switched‐capacitor (SC) filters, including the automatic sizing of transistors in the amplifiers and switches. The optimization procedure is based on genetic algorithms (GAs) where the circuit's fitness is first computed using equations describing the filter's transfer function and then using transient simulations. These equations are obtained using a fast numerical methodology that takes into consideration the electrical behavior of all components in the circuit. The poles and zeros of the SC filter's transfer function are computed using a system of differential equations, obtained from the inspection of the circuit. This system describes the filter's behavior for all switch combinations, including the non‐ideal effects of the transistors in the switches and amplifiers. Due to the low computational effort and accuracy of this methodology, it is possible to use a large population in the GA. After finding a solution through equations, the more computationally intensive SPICE transient simulations are used to fine‐tune the solution, with a much smaller population in the GA. Taking advantage of the equations' low computational load and accuracy, process, voltage, temperature (PVT) corners and mismatch errors optimizations are also performed, allowing the chromosomes fitness to be calculated taking into consideration multiple cases, thus resulting in a low sensitivity design.     

基于开关电容滤波器LTC1064的BPF设计

介绍了一种在2 kHz固定带宽条件下,中心频率可在0.5～100 kHz范围内调节的8阶椭圆带通滤波器的设计方法,采用2片LTC1064开关电容滤波器模块分别构成8阶椭圆高通和低通滤波器,然后两者级联构成带通滤波器,利用FPGA生成2路频率可控的时钟信号作为LTC1064的时钟输入,分别调节高通和低通滤波器的截止频率,从而实现带通滤波器的中心频率可调节,最后针对开关电容滤波器的直流偏移和时钟馈通问题进行后置滤波电路的设计.spice模型仿真结果表明,此带通滤波器的各项指标均达到了设计要求.     

Harmonic analysis of a single-phase rectifier with a DC filter capacitor

A single-phase diode bridge rectifier with a filter capacitor on the dc side is often employed to convert ac input into a dc voltage. The input current of the rectifier contains harmonic currents which cause undesirable power line effects. Recently, a method using the time domain analysis has been proposed to calculate the harmonic currents of rectifier considering noninfinite capacitance, i.e., non-zero dc side impedance. This method is very accurate, but it requires a long computing time and a complicated algorithm. This paper proposes a new method that makes it possible to easily calculate the harmonic currents taking into account the effects of the ac and dc side impedances of rectifier. The proposed method, which is based on the frequency domain method, can be executed only with the algebraic computation, and its accuracy is quite high. The validity of the proposed method is also demonstrated by comparison with the results of time simulation.     

滤波电路频率特性的仿真分析

采用理论计算和仿真分析的方法,对电阻和电容构成的无源低通滤波和高通滤波电路进行分析。理论计算主要研究传递函数,讨论响应的频率特性;仿真采用电子工作平台EWB软件,应用交流分析方法,从波特图仪中直观观察幅频响应和相频响应。仿真结果得到,在不同的频率下,电路输出的幅值和相位随着频率的变化而产生不同的响应,通过改变电阻和电容的参数,可得到不同的通频带宽度,说明仿真和理论分析的结果相同。但仿真分析相对硬件实验来说,优点在于改变元件参数时更加容易,仿真使电路分析更加灵活、方便。     

Nearly monotonic passband low‐pass filter design by using sum‐of‐squared Legendre polynomials

A new type of filter approximation, which utilizes orthonormal Legendre polynomials, referred to as sum‐of‐squared Legendre polynomials, is presented in this paper. Power transmission coefficient and the group delay of the proposed filter are compared with those of the Butterworth, Legendre–Papoulis, and Halpern filters. In order to illustrate the design of the proposed filter function, sum‐of‐squared Legendre polynomials coefficients and normalized element values of the low‐pass LC (inductor‐capacitor) ladder network prototype are given, up to the 10th degree. For continuous‐time domain filtering, doubly terminated LC ladder network topologies have very low sensitivities to changes of component values. In order to determine the effect of variation of all reactive components on the filter attenuation characteristic, the new sensitivity function has been proposed. Copyright © 2015 John Wiley & Sons, Ltd.     

Combined system of a series active filter and a shunt passive filter—an optimum design of the shunt passive filter

The combined system of a series active filter and a shunt passive filter that is proposed by the authors has the ability to eliminate a major disadvantage of shunt passive filters, namely, harmonic amplification. The series active filter needs a much smaller kVA rating than a conventional shunt active filter, and as a result, the combined system has good filtering characteristics and high efficiency. This paper presents an optimum design of the shunt passive filter that makes possible a great reduction in the required kVA rating of the series active filter. It can minimize the peak voltage across the series active filter and reduce the required kVA rating of the filter to 60 percent. A computer simulation geared to practical applications of large three-phase. twelve-pulse thyristor rectifiers is used to compare the compensation characteristics of the optimized system with those of a combined system that uses a conventional shunt passive filter. Experimental results obtained with a laboratory model of the filter corroborate the design approach.     

交流滤波器C1电容器保护配合策略研究

以南方电网各工程采用的交流滤波器C1电容器保护配合策略及运行情况为研究对象,对三种不平衡保护原理的优劣进行分析,指出当前计数法不平衡保护原理中存在的动作灵敏性、准确性的缺陷。综合比值法、桥差法和脉冲法的原理,提出了改进脉冲不平衡保护计数定值的建议,并首次提出了多段位计数的方法。基于一些特殊运行情况,提出了与桥差保护的配合思路。     

基于集对分析的中压配电网网架优化规划

分析了配电网规划中存在的各种不确定性因素,引入集对分析概念,指出该理论在解决配电网规划的各种不确定性因素时所具有的优势.论述了利用模糊集对分析理论建立中压配电网规划模型的原理和步骤,并通过Prufer数编码、伪随机初始化方式、适应度函数的选择、传统遗传操作算子的改进以及约束条件的处理等方面,运用遗传算法对模型进行求解.通过两组算例对得到的基于模糊集对分析的中压配电网规划模型的实现算法进行验证,计算结果表明本模型对中压配电网网架的规划非常有效.     

一种基于NSGA-II的低频谐振滤波器优化设计方法

舰船电力系统需要为船上各种用电设备提供安全稳定的电能,因此采用了各种电力电子装置完成电能变换,这些装置不可避免的会带来各种谐波干扰。由于受到体积重量的限制,在大功率电力系统中,若采用简单的EMI滤波器滤除低次谐波,由于所需的电容电感量较大,电感需要承担所有的工作电流,工程实现较为困难。在已知谐波频率的情况下,本文采用谐振滤波原理可在保证滤波效果的情况下有效减小滤波器的体积,并基于NSGA-II算法提出了一种谐振滤波器的优化设计方法。首先阐述谐振滤波的基本原理及设计方案,然后将谐振滤波器的初期投资、滤波后直流侧谐波含量,滤波设备的体积作为三个目标,利用NSGA-II算法求解谐振滤波器的参数。最终通过实验进行验证,设计的谐振滤波器具备良好的综合性能。     

A method of new filter design based on the co‐occurrence histogram

We have proposed that the co‐occurrence frequency image (CFI) based on the co‐occurrence frequency histogram of the gray value of an image can be used in a new scheme for image feature extraction. This paper proposes new enhancement filters to achieve sharpening and smoothing of images. These filters are very similar in result but quite different in process from those which have been used previously. Thus, we show the possibility of a new paradigm for basic image enhancement filters making use of the CFI. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(1): 36–42, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20699     

Harmonic spectrum analysis of the output voltage and grid‐side filter design for three‐level voltage‐source converters

Because of the complex arithmetic computation of the traditional three‐level space vector modulation (SVM), its hardware implementation is difficult to achieve. Moreover, the normal approach of acquiring the output voltage harmonic is sensitive to the simulation step, measurement accuracy, system noise, etc. This paper proposes a new method for analyzing the voltage harmonic spectrum of the three‐level converter. Furthermore, the minimum value of the inductance of the grid‐side filters is designed on this basis. First, the formulas of the duty cycle and the modulation waveform of the three‐level SVM algorithm are easily derived using some simple linear calculations under the 120° coordinate. Then, considering the characteristics of the digital circuits, the harmonic components of the output voltage are calculated using Fourier analysis. Third, a precise analytical design of the minimum inductance value of grid‐connected converters with LCL and L input filters is presented. Finally, the validity of this approach is verified by using experimental results. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A design of waveguide elliptic filter based on resonant diaphragms with a complex aperture

A novel approach to the synthesis of waveguide band-pass elliptic filters on the transverse metal resonant diaphragms with the complex aperture is proposed. The aperture of the diaphragm is considered to be a rectangular window with two L-shaped metal ridges. For the complex conductivity of the diaphragm, we solve the corresponding electrodynamic problem. We also construct and investigate an equivalent circuit of the resonant diaphragm containing a series-parallel LC circuit. The geometry of the diaphragm aperture is found to be corresponding to the parameters of the equivalent circuit. We construct a third-order elliptic filter and provide a computer simulation of the diaphragms satisfying the amplitude-frequency characteristics of its resonators. We show that some resonators can be located on one complex resonant diaphragm, which then reduces the length of the filter. The band-pass filter for a rectangular waveguide WR137 is developed and manufactured. The central frequency of the filter is 6.6 GHz, the passband width 7.5 % with return loss of −20 dB, and the total length is 34 mm.     

Steiglitz–McBride adaptive notch filter based on a variable‐step‐size LMS algorithm and its application to active noise control

This paper proposes a new Steiglitz–McBride (SM) adaptive notch filter (SM‐ANF) based on a robust variable‐step‐size least‐mean‐square algorithm and its application to active noise control (ANC). The proposed SM‐ANF not only has fast convergence but also has small misadjustment. The variable‐step‐size algorithm uses the sum of the squared cross correlation between the error signal and the delayed inputs corresponding to the adaptive weights. The cross correlation provides robustness to the broadband signal, which plays the role of noise. The proposed SM‐ANF is computationally simpler than the existing Newton/recursive least‐squares‐type ANF. The frequency response of the new SM‐ANF has a notch depth of about ?25 dB (for each of the three frequencies considered) and has spectral flatness within 5 dB (peak to peak). This robust notch filter algorithm is used as an observation noise canceller for the secondary path estimation of an ANC system based on the SM method. The ANC with proposed SM‐ANF provides not only faster convergence but also an 11‐dB improvement in noise attenuation over the SM‐based ANC without such a SM‐ANF. Copyright © 2015 John Wiley & Sons, Ltd.     

新型混合有源滤波装置的电流控制策略研究

针对混合有源电力滤波装置中有源滤波部分容量大小的问题,提出一种三相三线制并联型混合有源电力滤波装置的新型拓扑结构.这种混合有源滤波装置中每一相的无源滤波器与一个小的附加电感串联,并且这个附加电感通过一个单相耦合变压器与有源滤波器并联.其中,有源滤波器被控制成一个谐波电流源.这个附加电感为滤波支路的基波电流提供了通路,并且能够减小有源滤波器的输出电压.因而,有源滤波器的容量得到了有效的降低.详细介绍了包括负载电流检测、系统电流电测和复合控制的统一控制策略,并且讨论了该装置的有源滤波器的容量要求.最后,计算机仿真结果和实验样机的实验结果证实了所提出的新型混合式有源滤波器拓扑结构和统一控制策略是可行的并且是有效的.     

一种PSK接口电路的容差设计研究

介绍了电路容差设计、分析和分配的定义,并提出了一种基于EDA仿真技术的电路容差设计方法.该容差设计方法综合运用了参数扫描分析、灵敏度分析和最坏情况分析等多种容差分析手段,可以对电路中影响电路容差性能的关键参数进行仿真分析和确认.利用Saber软件将该容差设计方法应用在PSK接口电路中,根据容差设计步骤,通过调整电路组成元器件的参数标称值,并通过为各元器件分配公差,提高了该电路输出特性的容差性能,为提高航天电子产品的可靠性水平提供了一种新的途径.     

基于排序交叉优化算法的冷热电联供微电网经济调度

为提高冷热电联供微电网运行的灵活性,减少运行成本,将地源热泵引入微网,建立一种包含风机、光伏、微型燃气轮机、地源热泵、燃料电池、蓄电装置和蓄冷/热装置的冷热电联供型微电网经济优化模型,并提出一种排序交叉优化算法对各机组的出力进行优化调度.同时,为了满足负荷平衡等式约束和各机组出力约束,提出一种启发式约束处理方法.为验证...     

New class of filter functions generated directly by the modified Christoffel–Darboux formula for classical orthonormal Jacobi polynomials

The new solution of determining the prototype analogue filter function as the response that satisfies the specifications of all pole low‐pass continual time filter functions of odd and even order is presented in this article. The approximation problem of filter function was solved mathematically, applying the summed Christoffel–Darboux formula for the orthonormal polynomials. The starting point in solving the approximation problem is the direct application of the Christoffel–Darboux formula for the initial set of continual Jacobi orthonormal polynomials in the finite interval [?1, + 1] in full respect to the weighting function with two free real parameters. Solution for the monotonic and non‐monotonic filter functions is obtained in an explicit form, which is shown to enable generation of the Jacobi filter functions in a simple way by choosing the values of the free real parameters. Moreover, the proposed solution with the same criterion of approximation is used to generate for particular specifications the appropriate best known classical approximation functions of free parameters: the Gegenbauer, Legendre, and Chebyshev filter functions of the first and second kind as well. The example of the proposed all‐pole low‐pass lossless LC filter in the frequency domain for frequency responses of the 11th‐order filter is illustrated. This work is concerned with the approximation of an all‐pole low‐pass filter to design a circuit assuring an optimum realization of the required specifications. The article proposes new class filter functions with an approach to ideal filter magnitude characteristic. Copyright © 2012 John Wiley & Sons, Ltd.

     

Effects of the input filter on the stability of a voltage‐mode controlled buck converter

This letter presents a favorable effect of the input filter on the stability of a filter‐converter system, which employs a cascade configuration of a voltage‐mode controlled buck converter and a third‐order input filter. Such an effect can enlarge the stable region of the stand‐alone buck converter when appropriately selecting the damping resistor of the input filter. Effectively, the frequency‐domain model based on the extra element theory is used to analyze and illustrate the input filter interaction regarding this favorable effect. Our work provides a supplementary view for engineers to deal with input filter interaction. Copyright © 2007 John Wiley & Sons, Ltd.     

C波段高阻带抑制的微带带通滤波器设计

在二三次谐波处是否具有比较高的衰减是衡量低通和带通滤波器性能的重要指标之一.为了实现带通滤波器在二三次谐波处能有比较高的衰减,利用将发夹形带通滤波器与椭圆微带线低通滤波器串联的形式来实现此目标,其中串联椭圆微带线低通滤波器是为了更好的衰减二三次谐波.给出了利用ADS和Ansoft Designer的具体设计过程.最后测试结果表明:该滤波器通带内插入损耗小于4 dB,二三次谐波处具有50 dB衰减,整个阻带内衰减大于50 dB,满足了实际应用需求.