【作者】 张宏财；

【导师】 王学伟；

【作者基本信息】 北京化工大学 ， 计算机应用技术， 2010， 硕士

【摘要】 随着国民经济和科学技术的迅猛发展,电力系统中的非线性、冲击性、非对称性负荷显著增加,电能质量问题带来的经济损失越来越严重,如何有效的治理电能质量问题已经成为广大科技工作者研究的重点。改善和提高电能质量的首要前提是对电能质量扰动类型进行检测、分析与识别,只有快速准确地检测出电能质量问题,并进行有效的分析,识别扰动的类型,才能对其进行有效的控制和治理。本文系统地分析了电能质量问题的分类、产生原因及主要分析方法,并构建了电能质量扰动较完善的信号模型。利用目前电力系统中广泛应用的时频分析方法小波变换,对暂态电能质量扰动进行了时间定位,并分析了小波变换在处理电能质量扰动检测上的优点和性能。利用S变换对常见电能质量扰动的特征信息进行了检测,并分析了S变换在处理电能质量扰动检测上的优点。比较了小波变换和S变换在处理电能质量扰动问题时的区别,分析结果表明S变换比小波变换更适合应用于电能质量扰动检测与识别领域。为了实现电能质量扰动信号自动分类和识别,本文提出了一种基于S变换和最小二乘支持向量机的电能质量扰动分类识别的新方法：S变换主要用于提取电能质量扰动的特征向量；最小二乘支持向量机主要用于根据提取的特征向量对电能质量扰动进行分类识别。仿真结果表明,该方法识别准确率高,抗噪能力强,且训练样本少,训练时间短,适用于电能质量扰动辨识系统。最后,本文设计了基于DSP5416的电能质量分析实验平台的硬件电路,为进一步分析处理电能质量问题提供了基础。硬件电路主要由5个部分组成：数据采集模块、数据处理模块、串行通信模块、电源模块及复位模块。其中数据采集模块由信号调理电路和模数转换电路构成,数据处理模块主要由DSP数字信号处理器及外围存储器件组成。更多还原

【Abstract】 With the rapid development of national economy and scientific technology, a great deal of nonlinear, impact and unsymmetrical load increased significantly in the power system, power quality problems caused more and more serious economic losses, how to effectively reduce the impact of power quality problems has become a research focus of the technology workers. The first step to improve the power quality is the detection, analysis and identification of power quality disturbances. Only to detect power quality problems rapidly and accurately, conduct effectively analysis, and identify the type of disturbances, power quality problems can be controled and governed effectively.This paper systematically analysed the classification, causes and analysis method of power quality problems and established the signal models of power quality disturbances, identified the time of the transient power quality disturbances by using the wavelet transform and analyzed the characteristics of the walvelet transform in processing power quality disturbances, and detected the feature of common power quality disturbances by using the S-transform and analyzed the characteristics of the S-transform in detecting power quality disturbances. The comparison of the wavelet transform and S-transform in dealing with power quality disturbances showed the S-transform was more suitable for the area of power quality disturbances detection and identification.In order to achieve automatic classfication and identification of power quality disturbances, a new method based on S-transform and least square support vector machine was proposed. S-transform was used for extracting the feature vector of power quality disturbances and the least square support vector was used for classification and identification of power quality disturbances. Simulation results showed that the proposed method had an good performance on correct ratio and training speed, and strong resistances to nosies, so it is suitable to classification system for power quality disturbances.Finally, the hardware circuit of the power quality analysis experimental platform based on DSP 5416 was designed. The hardware circuit provided a basis for future analysis and processing of power quality problems. The hardware circuit was made up of the following five parts:data acquisition circuit, data processing circuit, serial communication circuit, power circuit and reset circuit. The data acquisition circuit consisted of signal conditioning circuit and analog-digital conversion circuit. The data processing circuit was mainly composed of the DSP5416 and external storage decives.更多还原