【作者】 赵永秀；

【导师】 傅周兴；

【作者基本信息】 西安科技大学 ， 电力电子与电力传动， 2003， 硕士

【摘要】 近年来，随着电力电子技术的广泛应用，非线性负载不断引入电力系统，造成电力系统中谐波含量急剧上升和电压波形严重“畸变”，致使电能质量下降。这些谐波给用电设备的安全可靠运行带来了极大的危害，同时对传统测量方法及常用工频仪表的使用也带来了一系列的影响。如果能够在电力系统运行前后对所有谐波参数进行准确分析，在满足电能质量谐波标准的基础上，就能有效地投运用电设备。因此，谐波分析是电力系统研究的一个重要方面。 电力系统谐波分析通常都是通过快速傅立叶变换(FFT)实现的，但是这种方法存在栅栏效应和频谱泄漏，使计算出的谐波参数即频率、幅值和相位不准，尤其是相位误差很大，无法满足准确的谐波测量要求。为了提高FFT的精度，本文在分析目前国内外各种谐波分析及测量方法利弊的基础上，提出了利用复序列加窗插值分裂基快速傅立叶变换(SRFFT)。该算法能极大地提高FFT计算的精度，从而满足谐波测量中对谐波参数的精度要求。文中给出了计算实例，实例表明该算法具有很高的计算精度，即使对于幅值较小的偶次谐波也能准确地求出其各项参数，尤其是对于提高相位计算的精度更为明显。 本文针对电力系统谐波测量的要求，设计数据采集电路。其中，运用PⅢ／800EB工控机来处理采样值，并使用并行口实现数据的快速传输。这样就大大减少测量时间，提高运算速度和抗干扰能力。为了消除频率混叠带来的误差，专门设计具有较好性能的低通滤波器和数字滤波器；由于系统频率波动性，设计有硬件电路组成的频率跟踪环节，最终实现采样周期和信号周期同步。并编写A／D转换驱动程序、控制程序和算法子程序，将它们应用于谐波测量单元，从而完成电力系统谐波分析。更多还原

【Abstract】 Recently, along with the broad application of Power Electronics Technology, many non-linear loads are used continuously in power systems, which make harmonic content rising rapidly, voltage shape distorting badly and power quality descending. The harmonics bring huge harm to equipment’s safe and reliable run. As the same time, these make a series of influence on traditional measure methods and common instrument in 50Hz.If all harmonic parameters are measured exactly, electro-equipments go into power systems effectively on base of satisfying power quality harmonic standard. So power systems harmonic analysis is a significant aspect of power systems research.Power system harmonic analysis was realized usually with fast Fourier Transform (FFT),but the method exits spectrum leakage, and can not analyse all harmonic parameters exactly, such as frequency, amplitude and phase, in particular has big phase error. The paper analyses the advantages and disadvantages of a large number of harmonic analysis methods and puts forward to a new algorithm in order to improve precision of FFT, which is plural list and interpolating windowed split-radix FFT(SRFFT).The simulating result shows that the algorithm can meet precision of harmonic parameters. Moreover a example makes know, it can calculate lesser even harmonics exactly. Especially it is more obvious to improve the pricision for calculating their phases.The paper designs a data gather circuit aimed at the require of power system harmonic measure . Industrial computer(PIII800EB) processes the fact sampling value, also with its LPT1 transmits fastly data to reduce the measure time , to improve velocity and anti-disturbance. The paper designs a more LPF and a numberical filter to eliminate the error, and a frequency tracing tache because system frequency fluctuatesceaselessly. This guarantes synchronization sampling. Moreover the result realizes Real-time power system hamonic analysis based on A/D conversion drivers, control programme and algorithm sub-programme.更多还原