Research On Error Analysis And Filtering Of Electric Energy Measurement Under The Background Of Harmonics

Power system has been accompanied with harmonic problems,and the development of electric power continuously promoted the development of power system harmonic.There are large number of harmonic sources in daily life,which leads to the decrease of power grid quality,the normal operation of power system equipment,at the same time seriously interferes with the accurate measurement of electric energy.The existence of harmonics in the power system has caused enormous economic and social benefit to the national power.So far the theoretical algorithms studied by domestic and foreign scholars on the harmonic problems on the harmonics problem of electric metering have been continuously improved,but they still need to be improved continuously when they are put into practice.Based on the harmonic detecyion algorithm of the energy metering system in the past,the comparison and combination of different algorithms are proposed to improve the accuracy of the energy metering.In order to solve the problem of large-scale error caused by the spectral leakage,the fence effect in FFT analysis and the wavelet base selected in the wavelet analysis,pro posed improved Hilbert-Huang harmonic analysis method and Kaiser window-based FFT.Analysis of the Improved Hilbert-Huang Transform in the presence harmonic sources or not harmonic sources suppresses the endpoint effects and modal aliasing problems by using the envelope extremum continuation method and the average empirical mode method.Design of Kaiser window based FFT filter harmonic analysis method using window function of recover coefficient to reduce amplitude error.Based on the measurement of electric energy,the energy metering simulation model is constructed by analyzing the principle of electronic energy meter structure.In the presence of harmonic sources or not,the electronic watt-hour meter to be measured current and voltage signal for high-precision sampling,according to the analog-digital conversion,current and voltage signals multiplied by the digital multiplier digital to obtain instantaneous power,through the low-pass filter extracts the active power signial and integrates the active power signal in time to obtain the measured power information.Calculate the active energy and reactive energy of each harmonic in a power calculation cycle and carry out the error analysis with the experimental results.