Research And Design Of Electromagnetic Interference For Calibrating Device Of Electric Energy Meter

Electric energy meter is an important device of electric energy measurement.Its measurement accuracy and reliability directly determine the fairness of electricity trading.Therefore,it is required to perform a full range,full performance test to ensure its performance.EMC detection is a key index and experimental content in many verification items of electric energy meter.In the process of verification of this indicator,the measurement error is larger due to the influence of electromagnetic interference.Therefore,in order to improve the accuracy of the verification test of electric energy meter,it is necessary to design an electric meter verification device which can meet the EMC test.In order to realize the accurate calibration of the electric energy meter in the electromagnetic interference environment.This paper will mainly study the electromagnetic interference design of the meter verification device.By analyzing the frequency spectrum of the interference signal,it chooses the appropriate electronic device to design the filter circuit to filter the electromagnetic interference signal.It first analyzes the principles and the internal structure of the meter and meter verification.It discusses the method of measuring the basic error of electric energy measurement.It studies the electromagnetic interference and electromagnetic compatibility related technologies,and defines the three elements of electromagnetic interference,namely interference source,propagation path and interference receiver.It also puts forward the common methods of EMC design.On this basis,it studies the anti-interference status of the meter verification device.It analyzes the sources of electromagnetic interference in the meter calibration device.It discusses the coupling of electromagnetic interference signals.It focuses on the analysis of the electric fast transient pulse group interference test and the radio frequency conducted immunity test interference of the meter verification device.Through the analysis of these two experiments,it defines the frequency characteristics of electromagnetic interference.It focuses on analyzing the methods and measures for the electromagnetic interference suppression of the meter verification device.It studies the related devices of restraining electromagnetic interference,and analyzes the basic frequency characteristics of five kinds of devices,capacitor,inductor,common mode choke coil,ferrite and photoelectric coupler.It designs the corresponding filter circuit according to the electromagnetic interference spectrum characteristics of current path,voltage path and pulse receiving circuit respectively.It gives a detailed analysis of the filter design principle,the selection of device parameters and schematic design.It analyzes the PCB design of anti electromagnetic interference circuit.It discusses in detail the basic content and points for attention of the filter PCB design.Finally,the filtering effect of the filter is verified.It uses actual measurements to measure the frequency characteristics of the front and rear ends of the filter.It describes in detail the characteristics of the interference pulse in the actual measurement experiment,the experimental equipment and the experimental results.The experimental results show that the effect of voltage path filter and current path filter is remarkable,and the frequency of EMI is better than that of the current path filter.