Study On The Influence Of Power Quality Transient Perturbation On Electric Energy Metering And Filtering

Electric as an efficient and clean energy, plays a very important role in people’s daily life and production. With the increase of nonlinear load in power system, causing a lot of transient disturbances, leading to the grid voltage and current changes. These transient disturbances are not only reduces the service life of the devices in engineering, but also affects the electrical energy measurement, increasing the error of electric energy meter, it is resulting in direct economic losses. In this paper, the wavelet transform and singular value decomposition algorithm are deeply studied, analyzing the influence of power transient disturbance on the measurement of electric energy meter, and the accuracy of the measurement of the electric energy meter is improved.In this paper, as the research background as electrical energy measurement wave filtering, transient disturbance as the object of study, presenting a combined with SVD and Dual tree complex wavelet transform based on MAP estimation algorithm, modeling in the MATLAB platform. Then using examples to verify the correctness of the simulation results. The main contents are as follows:(1) Introduced the basic principle of the wavelet transform filtering method. Detailed analysis of wavelet transform theory. It is mainly lists filtering principle and calculation method of hard threshold and soft threshold value, modulus maxima, Dual tree complex wavelet transform based on MAP estimation algorithm.(2) Used wavelet transform to filter the voltage transient signal and a variety of power transient signal. Using hard threshold, soft threshold, modulus maximum, Dual tree complex wavelet transform based on MAP estimation algorithm respectively to filter two kinds of signal. Getting waveform and SNR after denoising. It is found that Dual tree complex wavelet transform based on MAP estimation algorithm denoising effect of two kinds of signal is the best in the four algorithms. And comparing the filtering voltage error between mutation point information and the ideal value. The results show that Dual tree complex wavelet transform based on MAP estimation algorithm to the degree of retention in the point mutation is best.(3) Proposed a combined with SVD and Dual tree complex wavelet transform based on MAP estimation algorithm. First using the SVD algorithm to construct a binary matrix on the transient disturbance signal pretreatment, after processing the signal to noise is weakened greatly, then using Dual tree complex wavelet transform based on MAP estimation algorithm to filter, finally getting the SNR is higher, mutation of information is extracted, the situation is slightly better. According to the electric energy measurement formula of calculation theory to calculate the electric energy consumption value, the actual power consumption values and five filtering algorithm of electric energy consumption values, intuitive comparing and analyzing the five kinds of filtering algorithm and theory of electrical to point mutation in measurement error and filter information. The final results prove the correctness of the simulation experiment.