Research And Implementation Of Flicker Detection Algorithm

In recent years,with the development of smart grid and power electronic technology,and a variety of new energy into the distribution network as a distributed power supply,and the extensive application of nonlinear load,it is easy to generate power quality problems.In morden society,the electric energy is the most important secondary energy,and the voltage flicker is one of the important items in power quality detection,it should be detected effectively.First of all,flicker detection needs to extract the envelope of flicker amplitude wave,in view of the current envelope extraction algorithm,this paper mainly introduces the square demodulation method and Hiltber transform detection method,and uses a method based on Teager-Kaiser energy operator demodulation,it’s simple,and it can track the signal waveform in real time,the effectiveness of the detection is verified by MATLAB simulation.In the same time,due to energy operator demodulation method is sensitive to noise,in order to reduce the influence of white noise on the accuracy of the algorithm,this paper improved the wavelet threshold denoising method to eliminate noises from the acquisition signal,the simulation results show that the proposed method can overcome the influence of noise on the energy operator detection method.In this paper,the measurement method of flicker value recommended by IEC is analyzed,and the model is verified by Simulink.But it has some shortcomings,so this paper introduces the method of analyzing flicker value based on FFT,simplified calculation of flicker.However,considering the error of FFT under the asynchronous sampling conditions,the Nuttall window with excellent side-lobe performance and high accuracy of the triple-spectral-line interpolation algorithm are used to improve FFT.The algorithm formulas are proposed,and the simulation results prove the accuracy and effectiveness of the method.The algorithm not only has high accuracy,but also is easy for hardware implementation.Based on the flicker detection algorithm,a detector with micro controller TMS320F2812 as the core is designed.Determine the hardware implementation of the system.According to the modular design scheme,The software flow of each module is designed,the voltage flicker detection instrument has the functions of measuring flicker value,fault record storage,human-computer interaction and communication function.At last,the paper discusses the shortage of the system,and gives the expectation for future work.