Study On The Effect Of Harmonic On Electric Energy Metering

Due to the large number of power electronic devices and the access of nonlinear loads,more and more harmonics and interharmonics are mixed in the power system,which makes the harmonic problem of power system more and more serious.Harmonics can lead to a decline in the quality of power,which makes the use of electrical equipment and the grid to a certain extent affected.With the increasing attention and demand of power and quality for users and power supply departments,accurate harmonic analysis has become an important aspect of power quality research.This paper studies the influence of harmonic on the electric energy measurement from two aspects of accuracy and rationality.The main works and achievements obtained in this paper are as follows:(1)The importance of electric energy measurement in the calculation of economic settlement and technical index is analyzed.The universality of harmonic in the power system and the serious harm of harmonics are expounded,and the significance of studying the measurement of electric energy under the harmonic conditions is explained.(2)On the basis of the introduction of the structure of inductive and electronic two type electric energy meter,the measurement principle of induction and electronic watt hour meter is explained in detail.In the theoretical analysis of the influence of harmonic on the accuracy of electric energy measurement,the simulation test and analysis of these two kinds of tables are carried out,and the unreasonable points in the electric energy metering are pointed out by the analysis of current electric energy measurement.(3)The measurement test of the electronic watt hour meter and the induction watt hour meter is done in the harmonic state,and the measurement accuracy of two kinds of electric energy meters under different power factors,different single harmonics and different times harmonics content are tested respectively.Taking the switching power supply as an example,the rationality of the current electric energy metering mode is discussed based on the measured data.And the influence of harmonic distortion power on the rationality of electric energy metering.In view of the problem of electric energy measurement under the harmonic condition,this paper puts forward some suggestions for improving the current energy metering mode and the calculation mode of electricity cost,and realizes reasonable,accurate and fair measurement.