Research On Power Grid Harmonic Detection System Based On ARM

With the rapid increase of power electronic equipment and the increase of various nonlinear loads in the power grid,the harmonic content in the grid voltage and current is increasing.The harm caused by the harmonics has seriously affected the safe,economic and stable operation of the power system.The traditional harmonic detection device has been unable to meet the requirements of high accuracy and high efficiency.Therefore,a new generation of ARM hardware platform based on Exynos 4412 is proposed in this paper,and wavelet neural network is selected as the detection algorithm in this paper.Firstly,the current situation of harmonic detection at home and abroad,as well as the existing problems in harmonic detection,and then studies the related detection algorithms.The detection algorithm Fourier transform based and the BP neural network detection algorithm and the simulation results are analyzed.The simulation results show that the Fourier transform is spectral leakage and fence effect which can be improved by windowing and interpolation,but the detection error is relatively large.The detection speed and accuracy of BP neural network are better than Fourier transform processed with window and interpolation,but BP neural network has some shortcomings,such as slow training and easy to fall into local minimum.In view of the problems of the above two detection algorithms,the detection algorithm based on wavelet neural network is studied in this paper.A model of wavelet neural network is constructed,and the steps,training algorithm,initialization of weights and thresholds of wavelet neural network are given,and the basis for selecting wavelet function is provided.Simulation analysis of the wavelet neural network constructed in this paper shows that the accuracy and speed of the algorithm is much higher than the above two detection algorithms,which verifies the feasibility of the algorithm.Finally,this paper introduces the design of hardware and software of the whole system,Exynos 4412 is selected as the main control chip,and the hardware part of the LCD display circuit,communication circuit,memory circuit,signal transducer and conditioning circuit,AD conversion circuit and the button and the reset circuit are chosen and designed.In the software part,the overall process of the system is designed,and the program of communication,AD conversion,storage module and detection algorithm is designed,so as to complete the design of the whole system.