In this paper , the operation theory is ntroduced . we research the quasi . synchronous alternative sampling echnology in detail to improve the precision of the instrument and discuss some problem about the plication of this method . we introduce the develop of hardware and software in the whole instrument . at last , we sive out the result of experiment and the analyses of error 文中论述了该电参数测量仪的工作原理，着重研究了提高测量精度的准同步采样算法，并讨论了该算法在单片机中应用的几个实际问题。在此基础上，详细介绍了整个仪器的软硬件开发过程。最后对仪器进行了实验和误差分析，给出了实验结果和误差分析结果。
Simulations with respect to two models , prove that the method can track the frequency accurately and instantly , and have the preferable effectiveness on the abruptly fluctuating - frequency power signals , at the same time , this method overcomes the constraint of synchronous sampling and has the better astringency with different initial frequency 针对两种模型进行仿真，表明该方法能够较为精确与快速地跟踪电网频率，尤其针对突变频率的信号，具有较好的跟踪效果；同时算法克服了同步采样条件的限制，通过迭代，在不同初始频率下均具有较好的收敛性。
It deduces the interpolation formula of simultaneous sampling datum calculated by the asimultaneous sampling datum and uses fast fourier transform ( fft ) technology to calculate harmonic parameters . in the end , it gives harmonic errors " datum and curves by means of math model and computer simulation 在此基础上，导出了用非同步采样数据计算同步采样数据的插值公式，并根据复序列快速傅立叶变换（ fft ）原理对插值后的采样数据进行分析和计算，从而得到电网谐波参数。
At the same time , the method of disposal phase shift of ct by compensation is introduced . then the analysis and statistic of electrical power quality , the control scheme and compensating amount of capacitor for reactive power compensation are analyzed respectively . and in the paper , the control with a / y and the switch with ac contactor and solid state switch is valid measure not only for improving operate level economically and amending electrical power quality but also for avoiding of replacing switch frequently and decrease economic loss 然后对现有的算法进行了详细的分析、比较，筛选出既能满足硬件要求又可降低投资、保证精度、简化软件的方案，确定了准同步采样的方案，并通过对准同步采样误差的分析，提出了一种从45开始采样，从而提高精度的采样数据处理办法，同时，对于电流互感器相位漂移提出了一种补偿办法，接着对装置中电能质量分析与统计以及无功补偿中电容器的补偿量、投切原则也作了相应分析，其中对于无功补偿采用y混合接线，并利用交流接触器和固态开关共同投切电容，不但提高了经济运行水平、改善了电能质量，而且有效的避免了频繁更换开关，减少了经济损失；最后，设计了装置的硬件电路并绘制了相应的软件流程图。
Configuration and principle of sigma - delta a / d converter are simply analyzed in this paper , and the sigma - delta a / d converter is used in this measurement system . the history and development of digital sampling method are simply introduced in this paper . the important digital sampling " methods which include synchronous sampling method , asynchronous sampling method and quasi - synchronous sampling method are simply introduced and their specialties are compared in this paper 本文中对? a d转换器的结构和原理进行了简要的分析，并将其用于测量系统；简述了数字采样原理的产生和发展，对数字采样法中的三种主要方法即同步采样法、非同步采样法、准同步采样法做了介绍，并分别对其特点进行了比较。
This article has studied the deficiency and shortcoming of various kinds of methods of the parameter measurement of transmission line at present , proposed the measurement under operation on the basis of gps , researched gps application way and error that may appear in the power system synchronal sampling , put forward the parameter computing technology based on the information of both sides of transmission line , which solved some problems that exist in the parameter measurement , especially the problem that exist in the zero - sequence parameter measurement of transmission line with mutual inductance 本文研究了目前输电线路参数测量的各种方法，分析了其中存在的不足和缺点，提出了基于gps的输电线路参数在线测量方法，研究分析了gps在电力系统同步采样中的应用方式以及可能出现的误差，在同步采样的基础上提出了基于双端信息的线路参数计算方法，较好地解决了输电线路参数测量中存在的一些问题，尤其是多回互感线路零序参数测量困难的问题。
For the hardware , the device is an advanced data acquisition and parallel processing system required specifically by real - time signal monitoring in power system . a multi - channel sampling and retaining circuit , which makes it possible to acquire and transform data synchronously , is designed . to make the application of the device more flexible , two communication methods are offered , i . e . rs - 232 communication and ethernet communication 硬件设计方面,根据电力系统中数据采集和处理的实际特点,设计了信号的多通道采样保持电路,实现了多路信号的同步采样和快速转换;为了提高装置应用的灵活性,系统在通讯方式上,除了采用常用的rs - 232通讯方式,还提供了以太网通讯方式。
The controlling part of the comprehensive measuring instrument is 16 bits single - chip microprocessor 80c196kc . it is based on sampling theory and uses synchronous sampling algorithm to measure ac parameters of power system . it has many advantages as followed : complete functions , perfectperformance , portability , high - reliability , low cost and so on 该仪器以16位单片机80c196kc作为核心控制器件，采用同步采样法测量理论及实时数据处理方法，具有功能齐全、可靠性高、性能价格比高、便于携带等优点。
Because massive harmonic interference in the electrical network , it causes signal - sampling to include the very big harmonic in the measurement system , for eliminating measurement result influence by harmonic , the paper has an in - depth study of fourier transformation harmonics analysis measurement principle , analysis the forming reasons of frequency spectrum leakage and railing effect during measurement , achieves phase locked loop and frequency multiplier technique to realize integer - period synchronous sampling and eliminate impact of frequency spectrum leakage and railing effect in the result of measurement , and investigates in depth theory on phase locked loop and frequency multiplier technique , gives the method of realizing phase locked loop and frequency multiplier technique 由于电网中存在大量的谐波干扰,导致测量系统中取样信号也含有很大的谐波,为了消除谐波对测量结果的影响,论文深入研究了傅立叶变换谐波分析法的测量原理,分析了测量中频谱泄漏和栅栏效应形成的原因,提出了采用锁相环倍频技术实现信号的整周期同步采样,消除频谱泄漏和栅栏效应对测量结果的影响,并对锁相环倍频技术的理论进行了深入研究,给出锁相环倍频技术的实现方法。
Then , this thesis presents an algorithn of 2 - terminal quantity fault location based on synchronous gps sampling . this algorithm conducts fault location with only the 3 - phase fundemental wave voltage and current phasors of the 2 terminals of transmission lines and apples to lines of both symmetrical and asymmetrical parameters , irrelerant to the impedence , fault types and transitional resistance of the 2 terminals of lines 然后，本文提出了一种基于gps同步采样的双端量故障测距算法。该算法仅利用输电线路两端的三相基波电压、电流分量来进行故障定位，不受线路两端系统阻抗、故障类型、过渡电阻等因素的影响，对参数对称线路和非对称线路均适用。
