【作者】 邢耀广；

【导师】 黄纯；

【作者基本信息】 湖南大学 ， 电力电子与电力传动， 2006， 硕士

【摘要】 随着科学技术和国民经济的发展,人们对电能质量的要求越来越高,电能质量问题受到电力企业和用户的共同关注。电能质量指标监测是开展电能质量相关工作的基础环节。将虚拟仪器技术与电能质量监测相结合,只用很少的硬件投入就能开发出功能丰富的系统。基于虚拟仪器技术的电能质量测试仪应用灵活,升级方便,“软件就是仪器”的特色使测试仪各种通用功能和预期功能的方便实现成为可能。文章对电能质量的一些主要指标:电压、电流、频率、谐波、电压波动和闪变、三相电压不平衡度等的测量算法进行了分析,寻求适合虚拟仪器实现的,切实可行、计算精确、实用性强的计算方法。给出了基于频谱校正的电气信号测量新算法与基于FFT分析的闪变计算方法,这两种测量算法均是建立在非同步采样的基础上,节约了硬件开销,可以最大限度的发挥软件的优势。在LabVIEW软件开发平台上对算法进行了仿真,对影响测量结果的因素进行了分析,证明了算法的精确性和可行性。本文开发了基于虚拟仪器的电能质量测试仪,完成了装置的硬件选型和相关软件模块的设计。测试仪可以对电网上的电压电流数据进行实时采集,并通过后台软件系统利用选定的计算方法对采样数据进行分析计算,得到所需各种电能质量指标的实时数据,并具有友好的人机界面,丰富的统计、计算,数据储存,报表打印等功能,且具有广泛的扩展升级空间。经样机的实验室试验,测量精度达到国家相关标准,其性能指标完全满足电能质量综合监测的需要。更多还原

【Abstract】 With the development of science, technology and economy, power quality problems are concerned by both power supply enterprises and customers, and the detection of power quality parameters becomes more and more important. Combining the latest virtual instrument technique with power quality measurement, a power quality detecting system with richer function but less cost in hardware is developed in this paper.In order to get suitable algorithms which are accuracy, feasible, practical and convenient to be realized by virtual instrument, this paper firstly analyzes measuring algorithms of major power quality parameters, such as voltage, current, frequency, harmonics, flicker, unbalance factor etc. Then two algorithms, the one for basic power quality parameters measurement based on spectrum correction and the other one for flicker measurement based on FFT, are presented. Both of algorithms adopt asynchronous sampling, which can save hardware expenses and make the best of the advantages of software. The algorithms, as well as the factors that impacts the measuring accuracy, are analyzed and tested by the simulations on LabVIEW platform; at the same time, the feasibility of the algorithms on LabVIEW platform is verified.Based on the above study, a power quality measurement instrument is designed. The method of hardware type selection and design of software module is detailed. The instrument not only can realize real-time sampling of voltages and currents in power system, but also can calculate the power quality parameters with the presented algorithms. With friendly interface, the device has various functions such as data saving, analysis, report forms print etc. It is convenient to use, and has extensive promotion prospects too. Practical operation proves that its performance can meet the various needs of power quality measurement.更多还原