【作者】 孙益辉；

【导师】 陈众；

【作者基本信息】 长沙理工大学 ， 电力系统及其自动化， 2009， 硕士

【摘要】 谐波带来的影响己经严重危及到电力系统的安全、经济、稳定运行。解决谐波污染的关键在于精确实时地确定谐波的成分、幅值和相位等因素。而今普通工业控制计算机已越来越不能满足系统运行的高效性、高实时性、高稳定运行性和高可靠性等要求,给谐波的测量带来误差,因而开发新一代基于ARM平台和嵌入式Linux系统的电力谐波检测装置来满足这些要求显得很重要。同时,友好的图形界面也己经成为人们普遍关注的一个热点问题。电力谐波检测装置的图形用户系统更是存在着进程独立、网络通信能力、跨平台等特殊需求。在众多的图形用户界面软件中,因QT/Embedded具有跨平台、面向对象、能设计精美的人机界面等优点,系统便选取QT/Embedded作为支撑平台,并解决了QT/Embedded跨平台移植和中文化等问题。因频谱泄露和栅栏效应以及系统基本频率的波动,普通的FFT算法不能准确测量谐波和间谐波成份。为了提高测量精度,本文先用频域插值法确定系统的基本频率,以及插值多项式方法重构时域采样信号,接下来用FFT计算整数次谐波成份,以及频域插值方法计算间谐波成份。系统选用长沙科瑞捷机电有限公司提供的基于ARM处理器的SAM7430模块,在此基础上开发谐波检测软件,包括数据采集、FFT分析以及界面显示程序。经初步调试系统工作稳定可靠,具有一定的实用参考价值。更多还原

【Abstract】 The impact of harmonics has been a serious threat to security, economic, and stable operation of power system. To solve the harmonic pollution lies in the accurate, real-time to determine the composition, amplitude and phase of harmonics. Now the general industrial control computer has become increasingly unable to satisfy the requirements of high effects, high real-time, high stable and high reliability of systems operation, and brings to the harmonic measurement error. Thus to develop a new generation of power harmonics detection devices based ARM and embedded Linux system to meet these requirements is very important.At the same time, a friendly graphical interface becomes a hot issue. Graphical user in power harmonics detection devices has such special demands as process independence, network communications, cross-platform. The QT/Embedded has advantages of cross-platform, object-oriented, and etc., so the system will select the QT/Embedded as a supporting platform, and solved its cross-platform migration and Chinese Localization.Because of spectral leakage and picked-fence effects associated with the system fundamental frequency variation, a direct application of the FFT algorithm may lead to inaccurate results for measuring harmonics and interharmonics. In order to improve the measurement accuracy, a frequency-domain interpolation approach is adopted to determine the system fundamental frequency, and the polynomial interpolation method is applied to reconstruct the sampled time-domain signal,it is followed by using the FFT to calculate the actual harmonic components. Then, the frequency-domain interpolation is again applied to find the interharmonic components.The System selected SAM7430 based on the ARM processor, on this platform, the harmonic detection software including data acquisition, FFT analysis and graphical interface is developed. The initial testing proved that the system can work reliably and has a reference and practical value.更多还原