【作者】 房国志；

【导师】 赵洪；

【作者基本信息】 哈尔滨理工大学 ， 精密仪器及机械， 2013， 博士

【摘要】 本文针对电力系统中存在的暂态扰动、暂态谐波与间谐波等电能质量问题如何准确定位和快速检出，进行了系统的分析与相关检测算法的研究，以及这些算法以硬逻辑方式在FPGA中实现。为了有效地检出在电网中存在的暂态扰动信号，去除噪声，本文提出了一种改进的小波阈值去噪方法，该方法在阈值点具有连续性，克服原系数与小波系数之间恒定偏差造成的重构精度的不足，但是运算量大。针对这一问题，提出了一种混合广义形态滤波器去噪法。该方法运算量小，去噪的同时能更好的保留波形的特征量，且结构简单。为了择优选取小波函数和增强检测算法的抗噪性，本文对比8种常用小波函数的特性。仿真分析表明，Meyer小波函数的定位精度比采用其他小波函数好，但是运算量大。本文提出一种改进的形态小波算法，该算法可对暂态扰动有效检出，同时具有去噪功能，该方法结构简单、运算量小等特点。为了快速检出电网中存在的且有是我们关注暂态谐波信号，本文提出了FFT和小波包的方法检测暂态谐波。该方法对谐波信号进行FFT运算，确定频率成分，根据相应频谱，确定分解频段，然后得到无频谱泄漏的各次谐波分量，实现暂态谐波的检测，解决了小波包运算量大的问题。针对暂态谐波检测问题，本文提出了FFT变换和Meyer小波的法检测暂态间谐波。通过FFT运算得到相应的频谱，确定信号的中心频率，得到无频谱泄漏的各次间谐波分量，实现暂态暂态间谐波的检测。鉴于FPGA具有并行处理、灵活性强、实时性好等特点，本文提出了采用DSP Builder实现对暂态信号检测，并以高通和低通分解滤波器的形式实现小波变换算法及扰动信号的快速分析。并对小波算法进行了实时性优化。更多还原

【Abstract】 This paper aims at how accurate positioning and rapid detection the existingproblem in power system such as transient disturbances, transient harmonics andinter-harmonics. The paper carried out a systematic analysis and correlationdetection algorithm, and the way these algorithms in hardware logic implementedin the FPGA.In order to effectively detect and denoise the disturbance signal, animproved wavelet thresholding method was proposed, to overcome the originalconstant coefficients and wavelet coefficients deviation caused by the lack ofreconstruction, but it has a large amount of computing time computation. Tosolve this problem, a hybrid generalized morphological filter denoising methodwas proposed. this method has a small amount of computation and the structureis simple.In order to merit-based selection the wavelet function and enhanced noiseimmunity detection algorithm, this paper compared eight kinds of commonlyused wavelet features. Simulation results show that, Meyer wavelet functionpositioning accuracy better than using other wavelet function, but it has largeamount of computation. This paper presents an improved morphological waveletalgorithm can effectively detect transient disturbances, but also has de-noisingfunction, the method is simple, less calculation and so on.For fast detecting of the transient harmonic signals, a FFT and waveletpacket method was proposed to detect transient harmonics. The method use FFTto identify harmonic components, determine the frequency components, and thenget the harmonic components with no spectral leakage, to achieve the detectionof transient harmonics to solve the large amount of computation of waveletpacket problem.For transient harmonic detection problem, we propose a FFT and Wavelet Meyer method to detect interharmonic. We use FFT to identify interharmoniccomponents, determine the frequency components, and then get the harmoniccomponents with no spectral leakage. Achieve the transient inter-harmonicdetection.In view of the fact that FPGA has the characteristics of parallel processing,high flexibility, good real-time, this paper uses DSP Builder to achieve transientsignal detection, in the form of high-pass and low-pass filter to achieve wavelettransform algorithm and analysis disturbance signals And the wavelet algorithmfor the real-time optimization. Optimize the wavelet algorithm in real time.更多还原