Analysis Of Run-length And Harmonic Characteristics Of Power Dynamic Load And Evaluation Of Dynamic Test Signal

The development of the Energy Internet brings convenience and a series of challenges.The nonlinear load in the power grid increases,the harmonic content increases,and the load presents random fluctuation characteristics.These characteristics bring challenges to the measurement accuracy of smart electric energy meters.Therefore,analyzing the fluctuation characteristics and harmonic characteristics of the load current to provide a basis for testing the dynamic error of the smart electric energy meter has become an urgent problem to be solved.First of all,the research status of power load modeling,dynamic test signal modeling and power harmonic analysis are introduced.Summarize the impact of the introduction of nonlinear loads into the power grid,and point out that dynamic test signals can reflect the importance of load characteristics.Secondly,the run-length distribution characteristics of typical high-power loads are analyzed.Based on the run-length distribution characteristics of the load,the relationship between pseudo-random dynamic test signal model parameters and load characteristics is established,which provides preconditions for evaluating pseudo-random dynamic test signals.Thirdly,From the perspective of the influence of different load types on the electric energy meter,the method of power load classification is studied.According to the work system classification and the run distribution characteristics of the load,a detailed classification of the load power load based on the run characteristics is proposed.At the same time,according to the load classification of run-length characteristics,the relationship between dynamic test signal model parameters and dynamic load types is established.Then,the harmonic distribution of IT line and IF line of LanzhouWulumuqi high-speed railway is analysed by FFT and Hanning window method,and the average possession rate of 2-10 harmonic is given.Finally,by setting up an experimental system and using a non-synchronous test method,the errors of different manufacturers’electric energy meters under dynamic test signals are tested.The experimental results show that the pseudo-random dynamic test signals with different parameters can characterize the impact on the dynamic error of the smart electric energy meter under the above-mentioned detailed classification of electric load conditions;Under different electric load characteristics,the dynamic error of the electric energy meter has a big difference.It can provide an improvement direction for the smart electric energy meter to improve the accuracy.