Dynamic Load Signal Modeling And Dynamic Error Test Software Development Of Waveform Acquisition And Communication

In recent years,high-power dynamic loads in smart grids have been increasing,and the complex dynamic characteristics of loads have led to large out-of-tolerances of electricity meters in electric energy measurement,which seriously affect the accuracy of electricity charging.Therefore,analyzing the dynamic characteristics of the dynamic load,finding out the essential characteristics and characteristic parameters that affect the accurate measurement of the smart electricity meter,and establishing a dynamic test signal model that can reflect the essential characteristics of the dynamic load have important theories for evaluating the dynamic error of the smart electricity meter Significance and practical application value.This paper first introduces the research and development status of high-power dynamic load characteristics analysis and power decomposition methods.Secondly,the characteristics of two common high-power dynamic loads of electrified railways and electric arc furnaces are analyzed;the random process of dynamic loads is defined,and the mathematical model of the non-stationary random process of dynamic load transient signals is established;The modulation model of the quasi-steady-state term and dynamic term signal in the random process of dynamic load.Thirdly,the harmonic decomposition method based on wavelet transform is introduced;the quasi-stable state signal decomposition criterion is defined,and a least-squares empirical mode decomposition method for the quasi-stable state and dynamic modal signals of dynamic load current and power fundamental signals is proposed,The signal is divided into quasi-steady-state terms and dynamic terms;by writing MATLAB program to decompose the signal collected in the field,the decomposition results are given.Then,the decomposed modal signal is analyzed to define the characteristic parameters that characterize the essential characteristics of the quasi-steady-state term and the dynamic term.According to this,a dynamic error test experiment is designed.The influence of dynamic characteristics of dynamic load on dynamic error of the electricity meter is given.The experimental results show that:the essential characteristic parameters proposed in this paper can be used to determine the test experimental scheme and set the test signal parameters to solve the dynamic error test problem of the smart electricity meter.It also proves the feasibility of the mathematical model theory in this paper and the effectiveness of the modal decomposition method.Finally,the upper computer software part of the HE5025 dynamic error test device was expanded and developed.Using the Visual Studio 2008 software development platform and C++language,the signal waveform acquisition and display program and the accurate power serial communication program were designed and developed.The debugging and test verification have been completed in the test device.