Study On Electric Energy Measurement Method Of Distorted Signal Based On Multiwavelet Transform

With the rapid development of modern industrial technology,a large number of nonlinear devices and devices are connected to the power grid,resulting in serious distortion of the power grid signal.In particular,uncontrollable and phased rectifier equipment,which was widely used earlier,was widely used.These nonlinear loads will inevitably infuse harmonic pollution into the power grid when they are connected to the power grid,which will affect the quality of power and lead to the error of electric energy metering.The existing metering methods can not be accurately measured in such a case.At the same time,so far,our country has not yet unified the measurement standard under such a distortion condition,nor has studied the accurate and reasonable measurement method based on the general model.Therefore,this article has carried on the thorough research to this question.In this paper,a nonlinear load signal model under distorted signal condition is established by using Wiener functional series.The correctness of the model is verified by testing three typical nonlinear loads.Secondly,a simplified model of the current network,the signal power condition of distorted signals and the expressions are given,the analysis of the traditional electric energy measurement method in the current distortion under the electrical energy measurement exists,then based on the Wiener functional model of the nonlinear load of three kind of typical simulated the power flow,the experimental results show that the application of Wiener to establish the nonlinear functional load model can be used for power flow analysis,and gives the reasonable electric energy metering method.Then,the principle of multiwavelet transform based on information entropy is studied,and a Multiwavelet Based Power Metering algorithm is presented.The correctness of multi wavelet energy metering algorithm is verified by simulation analysis.Finally,a modularized way to design the distortion electric energy measurement instrument based on FPGA+ARM is designed,and the real-time test of multiwavelet algorithm is carried out on the tester.The results show that the Multiwavelet Based Power Metering algorithm has good real-time performance.The hardware part of the tester mainly includes analog signal generator,AD acquisition circuit,main operation module and peripheral configuration circuit.In software,the software design of multi wavelet power metering is completed.In addition,the GUI graphic interface module of the communication between ARM and FPGA and the test instrument is also designed.