井下能谱分析系统的电路设计

设计了一种用于对NaI晶体探测器核脉冲信号的幅度采样分析系统。对脉冲信号进行滤波放大。设计新型时序控制电路控制采样保持器对脉冲峰值保持。主控芯片为STM32F103VE。使用芯片内自带高速A-D转换器对保持峰值模一数转换。     

基于DSP的阻抗测量系统的研究

根据矢量电流电压法阻抗测量原理,以数字化测量思路,提出了一种基于DSP的阻抗测量系统。该系统以DDS信号源为测量激励,通过对标准电阻和待测阻抗元件两端的信号进行采样,将采样信号进行DFT,最终通过相关计算,实现待测信号的虚实分离,得出测量结果。系统通过设置采样频率和采样点数,有效避免了信号频谱泄漏现象而产生测量误差。通过测量试验验证,给出了几种主要测量误差引发的原因以及减小误差的有效方法,最终保证了±1%的相对误差。相比利用相敏检波器和时间数字转换器测量阻抗,该系统在保证测量精度的同时,大大简化了硬件电路和软件设计。     

感应同步器信号放大研究

感应同步器信号放大电路是实现高分辨率轴角-数字转换的核心硬件。研究信号放大对测角系统测量误差的影响,提出放大信号间的相移导致测量误差,误差具有二次谐波特征。分析运放噪声对测角系统数字信号稳定性的影响,提出信号放大电路设计方案。设计并实现了感应同步器信号放大电路,解决了跟踪鉴幅型测角系统的16bit数字信号不能稳定显示的问题。     

用于FAIMS系统的微电流检测电路

为解决电容积分式电流检测法不能满足FAIMS快速测量要求的问题,设计了一种用于FAIMS系统的微电流检测电路。该设计运用I/V电阻反馈法对信号进行放大。通过屏蔽和滤波等设计,有效地降低了FAMIS系统对检测电路的高频电磁干扰。考虑到前端电路的噪声来源,采用合理的元器件和电路设计,运用两级放大将FAIMS系统中的pA级电流放大并转换到mV量级。通过采集卡,利用LabVIEW对测得的电流信号进行采集和数据处理。实验结果表明,该电路的测量精度优于0.1 pA,采样频率高于15 Hz。进行了FAIMS系统实验,测得系统输出的背景噪声为0.2 pA。以乙醇为实验样品,在载气（N2）流量为0.8 L/min的情况下,得到了乙醇的FAIMS谱图,证明了该微电流检测电路可用于FAIMS系统。     

基-2 FFT在音频分析及输出系统中的应用

主要介绍了一种将FFT算法移植到单片机上运行,通过对数字音频信号进行分析处理,以实现音乐频谱实时显示和声音输出的系统。系统硬件部分主要由声音输入、单片机模数转换、由LED组成的点阵单元以及声音信号放大输出等电路组成。利用高性能STC12C5A60S2单片机内建的模数转换功能,先将输入的音频信号采样、量化转换为数字信号,再通过软件编程进行FFT运算。输出处理结果点亮LED点阵,完成频谱显示。LED的明暗由音乐的频率变化决定。通过LM386运放芯片及外围电路将输入的音频信号进行放大后,由喇叭或者外接音箱输出。该设计不但具有较高的实用价值和观赏性,而且硬件电路结构简洁,开发、制作成本低。     

一种基于准均匀采样的电力谐波分析方法

针对电力谐波的准同步加窗分析法存在所用信号周期多、计算复杂和谐波泄漏分布不均匀等问题,基于准均匀采样提出了一种仅需1个信号周期特别适于单片机快速、准确实现的电力谐波分析方法。准均匀采样的时间离散误差不随连续采样而积累,在1个信号周期内取2的整数次幂个同步采样点,直接采用FFT算法即可实现谐波分析。基于信号的基波近似,并假设信号采样时的时间离散误差和幅值量化误差均服从均匀分布,对采用准均匀采样的电力谐波估计误差进行了分析。给出了基于准均匀采样电力谐波分析的算法和具体实现流程,流程中通过长整型变量对采样时间进行精确控制,算法简单高效。最后对准均匀采样谐波分析算法进行了仿真,结果表明基于通用单片机即可实现电力谐波的快速、准确分析。     

一种镜像频率抑制方法研究

针对实际采样中往往有对镜像频率进行抑制的需要,提出了一种基于广义逆的镜像频率抑制系统,利用周期非均匀采样的时间延迟为采样信号的中心频率的四分之一时两通道相位差为干90°的特点,借助联合子空间理论把镜像频率抑制的过程转换为矩阵向量运算,通过广义逆就可以得到抑制的信号;由于采样通道的失配误差,提出了一种前向固定式误差补偿方式;并与传统的镜像抑制方式进行了比较得出了提出的方法在抑制效果等方面都好于传统方式.     

高电压系统电流在线监测的研究

文中介绍采用空心电流互感器采样电网电流,并将其输出的电压信号放大,处理,转换为频率信号,经空间传送的方案,实现了高电压系统电流在线自动监测。     

基于ARM的瞬变电磁数据采集系统设计

为了适应地质探测的要求,结合便携式探测系统的设计思想,根据瞬变电磁信号的特点,设计了基于ARM的高采样率和高准确度的瞬变电磁数据采集系统。通过实验测量,系统采样速率达2μs,误差为10 mV,可以满足实际使用要求。该系统的特点是:使用精密放大器组成的电阻网络对二次场信号实现了分段放大,避免了前期信号出现饱和,同时后期微弱信号可以得到准确采集;使用先进先出(FIFO)存储器节约CPU时间,保证AD7677对瞬变电磁前期信号的采集速率。     

变电站高压设备绝缘在线监测的误差分析与处理

定性分析了可能影响集中式绝缘在线监测系统监测结果的多种因素,包括传感器的角误差、信号的传输方式、PT角差、环境温湿度、并列设备的相间干扰以及A/D转换时的采样位数与采样速率。针对不同的影响因素提出了相应技术措施和对系统误差的处理方法。     

Digital input filters for measurement,control and protection of electric power systems

Power system control and protection equipment has required higher sensitivity and operational reliability than conventional one. Studies of digital signal processing suitable for electric power systems fulfill this objective using fast sampling and digital filtering by a 32-bit floating point DSP (Digital Signal Processor). The sampling rate of 3 kHz is carefully selected in order to separate the power spectrums of the A-D conversion output errors from the signal bandwidth. The new 12-bit A-D conversion unit equipped with a recursive-type digital filter achieved the equivalent high resolution of 14-bit conversion. This paper describes the design concept and the characteristics showing applications to current differential relays, distance relays and power system controllers.     

Digital input filters for measurement,control and protection in electric power systems

Power system control and protection equipment is subject to especially stringent sensitivity and operational reliability requirements. Projected digital signal processing systems suitable for electric power systems fulfill these requirements by means of fast sampling and digital filtering by a 32-bit floating point DSP (Digital Signal Processor). The sampling rate of 3 kHz is carefully selected in order to separate the power spectra of the A-D conversion output errors from the signal bandwidth. The new 12-bit A-D conversion unit equipped with a recursive-type digital filter achieved a high resolution equivalent to 14-bit conversion. This paper describes the design concept and the operating characteristics and illustrates applications to current differential relays, distance relays and power system controllers.     

数字仪冲击刻度系数的校准和测量误差的研究

本文介绍了数字仪的误差，数字仪冲击刻度系数的校准和数字仪冲击测量误差的计算，讨论了冲击电压数字测量的信号处理，研究了温度对数字仪冲击测量误差的影响。     

Comment and discussion on digital processing of PD pulses

Some of the more salient aspects of the digital processing technology of PD signals are examined. Most of the efforts in this field are concentrated on the application of digital analyzers for pulse height analysis, pattern recognition and identification of the physical phenomena. It is demonstrated that errors in the signal processing unit can lead to dominant mistakes in the interpretation of the test results     

Error control coding

The basic goal in digital communications is to transport bits of information without losing too much information along the way. The level of information loss that is tolerable/acceptable varies for different applications. The loss is measured in terms of the bit error rate, or BER. An interesting application that employs error control coding is a system with a storage medium such as a hard disk drive or a compact disc (CD). We can think of the channel as a block that causes errors to occur when a signal passes through it. Regardless of the error source, we can describe the problem as follows: when the transmitted signal arrives at the receiver after passing through the channel, the received data will have some bits that are in error. The system designer would like to incorporate ways to detect and correct these errors. The field that covers such digital processing techniques is known as error control coding     

基于DSP5416的语音采集与保密通信的实现

设计了基于数字信号处理器TMS320VC5416的语音保密通信系统。主要包括语音信号采集和数字信号处理2个模块,采用I2 C模式控制和SPI模式传输信号实现无缝连接。语音信号采集模块采用TLV320AIC23芯片,进行语音信号的采集和编解码。核心处理器采用循环异或算法,对音频信号进行加密或解密处理。设计系统语音采集与传输主程序和保密子程序,并调试实现了保密通信功能。测试结果表明,该系统实现方便、算法精度高、抗干扰性能力强,能够满足实时信号处理和保密通信的基本要求。     

On-line correction of errors introduced by instrument transformersin transmission-level steady-state waveform measurements

The successful implementation of a transmission level harmonic measurement system requires accurate and reliable measurement of harmonic voltages and currents. Existing substation instrument transformers are designed for 60 Hz measurements and they have been shown to cause resonance errors in the measurements. In this paper, we propose an on-line error correction method to correct for these resonance errors as well as possible saturation errors. The error correction is formulated as an output tracking problem where the distorted measurements are used along with the experimentally developed transformer model to reconstruct the transformer input. The method is generic, thereby permitting its use with any measurement system that utilizes a transducer with nonideal properties. It is also cost effective since it can be implemented on a personal computer or a digital signal processing chip     

基于LabVIEW的数字信号处理虚拟实验室构建

本文首先简要介绍了当前数字信号处理教学的现状,并针对目前实验室的具体情况,分析了研究虚拟实验室的必要性及意义。并在此基础上使用LabVIEW构建了数字信号处理虚拟实验室。该系统界面友好,维护简单等优点。此外,用户可以根据需要对典型的数字信号处理实验参数进行设置。实验证明该系统具有很好的教学实验效果。     

Decoding information on the state of electrotechnical objects by using Reed–Solomon codes

This paper considers the problem of digital information processing by the example of encoding and decoding the control signal of a wireless working cycle correction technology for an autonomous electrical grid. Being subjected to random interferences or intentional attacks, the encoded signal may be decoded incorrectly, causing disruption (change) in the system operation. In this work, we simulate different types of interference. For subsequent software implementation, algorithms are proposed that simulate group and single errors, as well as errors that are combinations of these two types. The effects of errors of different types on the results of decoding the compressed and uncompressed image files are investigated. This paper also proposes some options for representation of graphic files encoded in the software implementation. The files are encoded using the Reed–Solomon codes and are decoded using the Guruswami–Sudan list-decoding algorithm. A comparison between the files obtained after decoding for different types of errors simulated in the process of encoding is presented.     

基于DSP的语音录放和数字回声的实现

数字信号处理是现代数字语音通信的核心技术之一,DSP技术的应用为实现语音信号的采集、处理和播放奠定了基础.设计基于DSP的语音信号处理系统,运用TMS320VC5416处理器和AIC23语音芯片构建出硬件平台.分析DSP处理器和Codec芯片性能特点,配置软件控制接口,实现数字音频数据通信传输.采用C语言和汇编语言混合方式编写系统主程序和模块子程序,调试实验语音处理系统的信号采集、数字回声和播放,实现语音处理系统设计功能.