Research On Two-way Electric Energy Measurement Technology Considering Harmonic/interharmonics

With the integration of distributed power sources,the realization of two-way energy metering has become a new demand for energy metering,and it also brings more serious harmonic/interharmonic pollution problems.The large increase in harmonics/interharmonics has a certain impact on energy metering.In order to make the electric energy measurement more accurate and fair,this article has launched the analysis and research on the two-way electric energy measurement considering the harmonics/interharmonics.First,according to the characteristics of household distributed power sources that are connected to the grid for self-generation and self-use,and the residual power is connected to the grid,the demand for two-way energy measurement is proposed.The harmonics/interharmonics generated after the household distributed power sources are connected to the grid are measured from the accuracy of the measurement.Based on the analysis from the perspective of fairness,it is necessary to consider the two-way energy measurement of harmonics/interharmonics,and based on the four-quadrant theory of power,the judgment standard for the direction of electric energy is explained,and based on this,the two-way electric energy considering harmonics/interharmonics is derived.The formula for measurement.Secondly,in accordance with the requirements of two-way measurement for the accuracy of harmonic/inter-harmonic parameters,the problem of FFT spectrum leakage under asynchronous sampling is analyzed and explained,combined with the spectral characteristics and characteristics of the existing window function,and the adjacent spectrum line of the cosine window function The phase characteristics between the adjacent spectral lines reduce the leakage of the remote spectrum components through the superposition of adjacent spectral lines.The improvement analysis of the window function spectrum leakage is made,a new DFT sequence is established,and four RifeVincent(I)with better characteristics are selected among them.Window made an improved interpolation algorithm,and deduced the parameter correction formula,which reduces the amount of calculation and also improves the measurement accuracy of the algorithm.The simulation shows that the proposed method still has good performance in the case of fundamental frequency fluctuations and white noise.On this basis,a two-way electric energy metering simulation verification analysis is done.In addition,when the inter-harmonics are close to the fundamental/harmonic,the improved window interpolation algorithm cannot accurately measure the fundamental/harmonic and inter-harmonic interference due to the main lobe interference.A spectrum separation based on quasi-synchronous sampling is proposed.Wave/interharmonic parameter measurement method.According to the frequency component superposition model,a new fundamental frequency measurement method is proposed,and the quasi-synchronous sequence reconstruction of 5th Newton interpolation is carried out.At the same time,the fundamental wave/harmonic of adjacent interharmonics is corrected through the mathematical model to accurately separate the fundamental wave /Harmonic and interharmonic components,complete accurate measurement of fundamental frequency parameters,harmonics/interharmonic parameters,simulations show that the proposed algorithm still has good performance in the case of fundamental frequency fluctuations and white noise,and is based on This method completes the two-way measurement simulation verification considering harmonics/inter-harmonics,and at the same time builds an algorithm experimental verification platform based on AD7606+DSP28335.