Improved harmonic suppression efficiency of single-phase APFs in distorted distribution systems

In this study, a control method is proposed to improve the harmonic suppression efficiency of the single-phase active power filter in a distorted power system to suppress current harmonics and reactive power. The proposed method uses the self-tuning filter (STF) algorithm to process single-phase grid voltage in order to provide a uniform reference grid current, which increases the efficiency of the system. The results of the simulation study are presented to verify the effectiveness of the proposed control technique in this study.     

UPQC检测控制方法研究

介绍了一种综合型的电能质量补偿装置UPQC的功能和结构,分析了它的检测控制策略.并在此基础上,提出利用瞬时无功功率理论中的同步坐标变换来提取电网电压基波正序相位的检测方法,它简单易行,实时性好,避免了大量对三的相量计算,且无须相不对称且畸变电压进行锁相和滤波.并介绍了根据UPQC内部功率平衡来实现的串连和并联有源滤波器的综合控制方法.仿真结果验证了上述检测控制方法的正确性.     

The design of low voltage/power current-mode sinh-domain filter for biomedical applications

This paper proposes low voltage/power, current-mode second-order Butterworth high-pass filter design in the sinh-domain for biomedical applications. The proposed filter is a continuous-time filter in the companding-class. Sinh-domain filters have the advantages of electronically adjusting the frequency response without the need for non-chip capacitors and full integration on the chip, providing low power consumption and offering a high dynamic range. These advantages of the sinh-domain are beneficial for biomedical applications due to its low power consumption requirement. The proposed filter topology is suitable for eliminating low-frequency interferences of biomedical signals like electrocardiogram (ECG), electroencephalogram (EEG), and electromyogram (EMG). In the realization of this filter, the method of simulation of passive elements with sinh-domain cells is used. The proposed high-pass filter in the 0.05 Hz-20 Hz operating frequency range with a 0.5 V power supply shows the power dissipation of 12.5 nW while its dynamic range exceeds 60 dB. Additionally, no resistances are used in the proposed topology. Simulations have been performed by using OrCAD Capture CIS to demonstrate the performance of the filter. These simulations have been implemented with the TSMC 0.25 µm CMOS process parameters.

     

基于传统功率理论谐波抑制和无功补偿方法

基于传统功率理论，提出了一种谐波抑制和无功补偿方法，根据有功功率可求等效线性负载，进一步求得该时刻补偿电流值。应用于有源电力滤波器控制中，可有效地抑制谐波电流和补偿无功功率，减小了电流信号检测中偶然误差对补偿效果的影响。这种方法可以应用在单相、三相电力系统的滤波电路中。仿真证明了这种方法的有效性。     

基于最小二乘法的电力电缆FBG传感测温系统

为了提高电力电缆测温系统的测量精度和速度,提出了以光纤梳状滤波器代替参考光栅提供拟合数据参考点,采用最小二乘法拟合光纤Bragg光栅波长和F-P可调谐滤波器调谐电压的线性关系,通过F-P可调谐滤波器解调FBG传感器中心波长变化的方法,完成对电力电缆温度的测量.研究表明,光纤梳状滤波器能够代替多个恒温参考光栅实现波长标定,对反射波长的测量误差＜5pm,温度均方误差≤0.7 ℃.     

零电流开关大功率DC/DC双全桥变换器设计

提出了一种基于双全桥结构的单向零电流开关大功率（兆瓦级）DC/DC变换器,该变换器通过采用两个全桥变换器来实现零电流开关,实现了较低的功率损耗和输出滤波电感。为了验证提出的变换器在大功率应用中的有效性,构建了小型样机并在大功率直流电网进行了实际测试。实验证明,相比传统的两种单向大功率全桥变换器,提出变换器所需的滤波电感和半导体器件的功率损耗均较少,分别仅为1.72mH和924.5kW。     

A novel control algorithm for active power conditioner without load current sensor

A novel control algorithm for an active power conditioner (APC) is proposed. The operation of this APC can be divided into two modes: active power filter mode and back-up power mode. When the mains are normal, the proposed APC operates in the active power filter mode that provides the functions of active power filter and battery charger. Once the mains have failed, the proposed APC operates in the back-up power mode to supply power to the demands. In this circuit design, the control circuit is suitable for both operation modes except in the arrangement of feedback signals. Hence, the design cost can be reduced; also, no load current sensor is used in the circuit. The practicality of the method is, therefore, further enhanced.     

应用于ΣΔADC的抽取滤波器的设计与实现

介绍了一种应用于ΣΔADC的抽取滤波器的设计和电路实现方法.通过对传统设计方法的分析,提出了一种可以节省10%硬件利用率的改进方法,同时提出了一种适用于半带滤波器的串并联结构,与传统的半带滤波器相比能够提高50%的硬件利用效率.在面积、速度和功耗的折衷的情况下,灵活应用CSD、CSE和多相分解结构,在0.18μm下实现了0.59 mm2的16位数字抽取滤波器.该滤波器与不应用串并联结构的滤波器相比能够节省18%左右的芯片面积.     

一种血氧饱和度检测芯片的低功耗设计新方法

提出了一种血氧饱和度检测集成电路的低功耗设计新方法,采用先电流滤波再对数放大的前端处理思路简化电路结构、降低功耗,在相同检测条件下,使LED驱动脉冲电流占空比从原来的3％降为0.3％甚至更低,使占检测系统功耗主要部分的LED模块功耗降为原来的1/10甚至更低.检测电路包括电流滤波器、对数跨阻放大器、电流模比值运算电路.仿真结果表明,在1.8V电源电压下,输入电流为2.7～15 μA时,芯片总消耗电流仅为22～80 μA.     

A new control system with a control delay compensation for a current-source active power filter

In this paper, a new control system for the current-source active power filter is presented. The harmonic current compensation is realized using combined feedforward control of the load currents and closed-loop control of the supply currents. The control system includes a simple method for compensating the sampling and calculation delays of the digital control system. The compensation in the proposed method is achieved using the regular LC filter of the active power filter as an energy storage for load currents, and no additional components is needed in the main circuit. Furthermore, the calculation power demand of the compensation method is very low and is, therefore, suitable for single-chip microcontroller implementations. The proposed control system is realized using a 32-bit Motorola MPC555 microcontroller. The simulation and experimental results show effective filtering performance also for higher order harmonics of the distorted load currents.     

A low power 8-tap digital FIR filter for PRML read channels

This paper presents a low power 8-tap digital Fourier infrared (FIR) filter for partial response signalling with maximum likelihood (PRML) disk-drive read channels. Enhancements on power consumption and speed are achieved by adopting the row compression scheme with a proposed conditional carry selection method. The 8-tap digital FIR filter is fabricated by 0.8µm CMOS technology and occupies by 3.9mm × 1.5mm. The experimental results show that the FIR filter operates up to 180MHz and dissipates 1.4mW MHz^?1 with 3.7V power supply. It is proved that 20% power reduction is readily attainable with the proposed scheme.     

A digital power spectrum estimation method for the adaptation of high-speed equalizers

This work presents a method to estimate the power spectrum of digital signals, which is then used to generate an error signal to tune Gbps data rate equalizers for digital communications. The proposed power spectrum estimation method can be realized with standard digital circuits and has been fabricated and tested in 0.35-/spl mu/m CMOS technology for 1-Gbps data rate. Compared with the traditional bandpass filter followed by a rectifier implementation, this method has wider input signal range and is scalable to higher speed technologies beyond the gigahertz range, in addition to largely reduced power dissipation and die area. Also presented are system simulations on the bit-error rate performance and the error space analysis of the proposed method in comparison with the method of using a bandpass filter followed by a rectifier.     

Design of optimal symmetric FIR receive filters

A method for designing optimal symmetric odd-length finite impulse response digital receive filters is proposed. The filter jointly minimises the mean power of intersymbol interference and additive noise or interference under the constraint that the filter coefficients are symmetric. The method yields exactly symmetric filters with the same performance as the earlier unconstrained design but with a lower computational complexity     

基于引导滤波的电力设备热故障诊断方法研究

电力设备热故障为一种常见的设备故障类型。本文提出一种基于引导滤波的电力设备热故障诊断方法。该方法包括两个主要步骤。首先,基于热故障区域与图像背景在红外图像上的温度差异特性,逐像素计算热故障区域与图像背景的马氏距离,获得初始的热故障诊断结果。然后,采用引导滤波对初始诊断结果进行优化,充分利用相邻像素之间的空间相关性,优化提升诊断结果。实验结果表明,与其他广泛应用的异常目标检测方法相比,本文提出的方法在热故障诊断精度上具有较大的优势,满足电力设备带电检测的应用需求。     

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     

一种基于有源滤波与光伏发电的并网逆变器控制方法

文中提出了一种基于有源滤波与光伏发电的并网逆变器的控制方法,在并联型有源电力滤波器的基础上拓展了新能源发电功能,采用电压电流双环对并网逆变直流侧电压和系统电网输出有功电流进行控制。该并网逆变器既可以滤除负载的谐波和补偿负载的无功功率,也可以实现有功功率的有效传输,适于未来微电网中并网逆变器的应用研究。     

A new simple method for analysing of thermal noise in switched-capacitor filters

Thermal noise is one of the most important challenges in analogue integrated circuits design. This problem is more crucial in switched-capacitor (SC) filters due to the aliasing effect of wide-band thermal noise. In this article, a new simple method is proposed for estimating the power spectrum density of output thermal noise in SC filters, which have acceptable accuracy and short running time. In the proposed method, first using HSPICE simulator, accurate value of accumulated sampled noise on sampler capacitors in each clock state is achieved. Next, using difference equations of the SC filter, frequency response of the SC filter is shaped by time domain analysis. Based on the proposed method, a SC low-pass filter and a second-order SC band-pass filter are analysed. The results are validated by comparing to the previously measured data.     

中性滤光片提高生化检测动态范围的研究

采用真空蒸发的方法制作变透过率的Cr膜中性密度滤光片,安装在CCD接受窗之前,不同程度的衰减卤钨灯能量相对过高的波段,使各部分能量趋于平衡,通过实验得出该方法能够提高可见部分的动态测量范围,并且为真空蒸发方法制作特定厚度膜层提供理论依据.     

基于线性神经网络预测的实时谐波检测

随着电力电子装置的应用日益广泛，电网中的谐波污染也日趋严重。准确、快速地检测系统电流中的谐波成分，是保证有源电力滤波器具备良好工作性能的关键。文中详细地阐述了针对电网中谐波变化的特点，给出一种谐波电流实时检测方法，能够正确预测出未来时刻的谐波电流值。本文给出的基于线性神经网络的实时谐波检测系统，可以利用前5个采样点的值来预测下一个采样点的值，也就是可以在第五个采样周期后准确地跟踪上基波的变化。实现了谐波检测的实时性。     

有源电力滤波器新型控制策略

基于瞬时无功功率理论和预测控制算法，提出了一种新型有源电力滤波器控制方法，该方法消除了电源电流在负载电流发生突变处产生的锯齿抖动。实时检测负载电流的二阶导数，判断负载电流是否发生突变。发生突变则采用预测控制程序模块进行补偿电流控制。这种方法可以应用在单相、三相电力系统的滤波电路中。仿真结果证明了这种算法的有效性。