交流采样电量变送器

文档编号:ZD611 文档字数:19524,页数:44，有外文翻译

摘 要
 用传统方法测量交流电气信号时，往往使用磁电式、电动式、感应式等常规模拟仪表，而现在一般都使用基于电子技术的变送器，将交流电气信号转换成直流信号后通过模数转换，再由计算机进行测量。随着微电子技术的发展，计算机直接对交流信号进行采样测量已进人工业实用阶段，这样不仅缩小了仪器体积，降低了成本，减小了时间延滞，而且提高了测量的准确度和精度，同时也为电力生产与使用中的调度管理全面实现自动化，为达到无人值班、少人值守创造了有利的条件。所以进行交流采样，设计出合理的硬件电路和编制出高效的检测计算程序是值得进一步探讨和研究的。
 本文分析了电量变送器的多种算法，指出了它们存在的问题。基于傅立叶算法的理论推导，提出了能消除衰减直流分量的幅值算法和高精度的测频算法。新的幅值算法对衰减时间常数未作假设和要求;测频算法根据传统傅氏测频算法存在的误差，通过实时调整修正系数的方法，实现了高精度地跟踪系统频率。结合算法，以80C196KC单片机为核心，详细介绍了电量变送器的硬件构成和软件编程。同时对A/D采样结果的处理和开平方算法提出了新的方法，并在硬件和软件两个方面上提高了变送器的可靠性。
 
 关键词：电量变送器，交流采样，傅立叶算法，单片机，频率测量
ABSTRACT
 Using traditional methods when measuring the exchange of electrical signals, often used magnetic-electric, electric, induction, such as conventional analog instrumentation, and now are generally based on the use of electronic technology of the transmitter, the exchange will be converted into electrical signals DC signal through modulus Conversion, then measured by the computer. With the development of micro-electronics technology, computer exchange of signals directly to the sample survey has industry people into practical stage, so not only reduce the volume of equipment, lower costs, reduce the time delay and improve the measurement accuracy and precision, But also for electricity production and use in the management of scheduling the full realization of automation, to achieve unattended, few people on duty to create favorable conditions. So exchange sampling, to design a reasonable hardware circuit and the preparation of a highly efficient testing program is worthy of further exploration and study.
 This thesis examines the various algorithms that are currently applied to electrical quantity transducer. It is identifies and proposes a magnitude algorithm, and frequency measurement algorithm, Both of which are based on the Fourier algorithm. The proposed magnitude algorithm can eliminate the decaying DC component, and the proposed frequency measurement algorithm can produce a high accurate output the new magnitude algorithm dose not require the decaying constant τ to be known in advance. The frequency measurement algorithm can accurately track the system frequency by adjusting the amendatory coefficient in real time according to the error of the original Fourier frequency measurement algorithm, The thesis introduce in detail the hardware structure and software programming of electrical quantity transducer, In combination with algorithm and based on single chip microcomputer-80C196KC.It provides new solutions for the handling of the result of A/D sampling and the square root algorithm. While the reliability of transducer is improved in both hardware and software.
 
 KEY WORDS：electrical quantity transducer, AC sampling, Fourier algorithm, single chip microcomputer, frequency

目  录

第1章 绪论 1
1.1 电量变送器及其在电力系统中的应用 1
1.2 交流变送器的发展现状 2
第2章 电力系统的信号及其测量方法 4
2.1 电力系统的信号 4
2.2 基于基频信号的各种交流采样测量方法及其特点 6
2.3 交流采样的电量变送器算法的选择 11
第3章 高精度测频算法的研究 12
3.1 傅立叶算法原理 12
3.2 高精度的测频算法 13
3.3 其它电量的计算公式 17
第4章 交流电量变送器的设计 19
4.1 电量变送器的硬件设计 19
4.2 电量变送器的软件设计 21
4.3 开平方算法的改进 28
4.4 电量变送器同步采样的实现 31
第5章 电量变送器的抗干扰措施 34
5.1 概述 34
5.2 软件抗干扰措施 35
第6章 结论与展望 37
参考文献 38
致  谢 40

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