Study And Inplementation Of Transient Power Quality Detection Method

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.