The On-line Detection Of Harmonic And Inter-harmonic In Power System

The on-line detection of harmonic and inter-harmonic in power system is cutting-edge technology and hot research topic in power quality research area.In this paper, harmonic power of the inter-harmonic detection core issue down "inter-harmonic harmonic preprocessing (denoising) --- Harmonic Detection ---Detect Inter-harmonics --- power harmonics detection device the design of "the main line of this technology, the use of wavelet transform theory, fast Fourier transform theory, interpolation theory, bimodal spectrum amendment theory, inter-harmonic noise power harmonics, harmonic detection, inter-harmonic detection, harmonic power device design systems.First, the traditional denoising algorithm is based mainly on the Wiener filter linear least squares method at the same time high-frequency noise, but least squares is also some useful information for fault diagnosis of high-frequency disadvantage, and based on wavelet Transform non-linear denoising algorithm can overcome this disadvantage, a threshold based on a custom function denoising algorithm and the algorithm-based de-noising effect HardThresh, SoftThresh function comparative study of algorithms. Simulation and experimental results show that threshold based on a custom function of wavelet denoising algorithm in power quality harmonic inter-harmonics detection is effective.Second, add a window based on Fast Fourier interpolation algorithm error characteristics of the power grid through the estimation of the fundamental frequency, and then use this integer multiple of the baseband sampling frequency of the grid containing harmonic signals Plesiochronous sampling, re-use Fast Fourier Transform to estimate the harmonic parameters. The proposed new method of simulation, simulation results can be adequately demonstrated that the method of measurement accuracy is better than windows add the Fast Fourier interpolation algorithm, during the quasi-synchronous sampling can be reduced when the sampling period, and further improve the algorithm real-time. Meanwhile electric power system in accordance with the characteristics of inter-harmonics, based on the bimodal spectrum of the amendment theory, proposed a new algorithm - "elimination" to carry out inter-harmonic detection. The proposed new method of simulation, simulation results show that the method of full inter-harmonic detection accuracy can be better. This method is easy to achieve at DSP Medium for Online Application of rapid detection devices. Finally,theory can be applied for the actual conduct of the power harmonics detection device. To hardware development platform for the OMAP5912, add a window using the Fast Fourier interpolation algorithm implementation harmonic detection parameters. The use of the algorithm can achieve in a non-synchronous sampling harmonic under the conditions of implementation parameters (frequency, amplitude, phase) of the accurate measurement, simplifying the hardware circuit. Focuses on the detection of the overall implementation of hardware devices and software design flow program. In software development using DSP / BIOS operating system, to facilitate the development process, the detection device have high measurement accuracy and good real-time, so very suitable for industrial applications, coupled with the OMAP5912 platform integrated ARM core network to facilitate implementation, it is worth popularizing.