Study On The Quantization Error Influence And Dynamic Error Of Electric Energy Metering Devices

Currently,smart grids have entered the lead-up phase.The large-scale access of new energy,the rapid construction of digital substations and the continuous increase of dynamic load have led to an increasing electric energy metering errors in the power system,causing huge economic losses to the country and society.Therefore,it is urgent to carry out study on the influence of quantization error and the dynamic error of electric energy metering devices,which will provide powerful theoretical guidance for the power measurement and dynamic error testing.Firstly,this paper introduces the development of transformer,electric energy meter and electric energy metering technology.At the same time,it analyzed the international research status of electric energy metering devices quantitative error influence and dynamic error in detail.Secondly,from the system point of view,the structured measurement model of digital energy metering system and smart energy meter are established.The working mechanism of A/D conversion,protocol framing and power measurement element as well as the source of quantization error and dynamic error are analyzed.It's the foundation for the study on quantizationerror influence and dynamic error of electric energy metering devices.Thirdly,aiming at the quantization error of electric energy metering devices,analytical expressions of average power uncertainty under the influence of the correlated quantization error in synchronous and asynchronous sampling are derived by means of general cyclostationarystochastic process power spectral density algorithm and autocorrelation function algorithm.The correctness of the theory analysis is verified by the Monte Carlo simulation and the experiment on a new PXIe-based digital metering instrument data collection system.The study has theoretical significance for the evaluation about random uncertainty with respect to the high-accuracy electric average power estimation.Finally,aiming at the dynamic errors of electric energy metering devices,the definitions of five important characteristics and the completeness condition of dynamic error test signal model are proposed.The general cyclostationary stochastic process theory and the input-output cross-correlation function identification method are used to prove the completeness of the m sequence modulating sine discrete(mSD)pseudo-random dynamic test signal.The internal influence factors that cause the dynamic error of the energy meter are revealed.The study has certain guiding significance for the dynamic error test signal model establishment and dynamic error test experiment of electric energy metering devices.