Research On High Precision Measurement Technology Of AC Signal Based On SOC

This paper based on SOC for ac electrical signal digital measuring method of theory analysis,put forward a new method for measurement of ac electrical signal effective value,different from traditional ac electrical signal measurement,this paper adopts the ac digital method for measuring the electrical signals of innovation,communication and digital method for measuring the electrical signal has carried on the comprehensive analysis,points out the ac electrical signal measurement,digital measurement of peak average and RMS measurement principle,starting from the principle of measurement is analyzed the three measuring methods,the applicable scope of the use of the effects of the three measuring methods,points out the practical significance of the ac signal effective value measurement.Simulated ac electrical signal after filtering pre-processing,use ADC sampling,make it become a discretization of the digital signal,FFT and window ac electrical signal spectrum can be obtained after calculation,spectrum after correction algorithm can get accurate signal amplitude calculation,again through the relationship between amplitude and RMS calculation,so as to achieve the aim of ac electrical signal effective value measurement.Not old function to get the amplitude spectrum of different precision,this paper adopts the method of comparative analysis,through the analysis of MATLAB ac electrical signal through not old function spectrum,mainly related to the rectangular window and Hanning window Hanning window and Flat(Flat Top)of three kinds of commonly used window function,through analyzing the frequency spectrum of the three types of window function,this thesis selects the spectrum amplitude,the more stable and accurate Flat Top window function to add Flat window ac electrical signal processing.Three kinds of window spectrum correction algorithms,energy center of gravity correction method,formula correction method(improved amplitude correction)and window spectrum peak search algorithm,were used to correct the spectrum after adding the flat top window,and the simulation results showed that the window spectrum peak search algorithm adopted could achieve higher measurement accuracy.This paper adopts the SOC is Xilinx company Zynq series of FPGA,this paper proposed ac electrical measuring method for experimental verification,the use of the PL side its powerful ability of logic operation in SOC for acquisition of communication signal add window and FFT calculation,using vivado write spectrum correction algorithms,realize the ac electrical signal and high precision measurement,proved this paper adopts the ac electrical measuring method,Under 200 hz frequency range of ac voltage signal,The absolute measurement error of the effective value is between ±4×10^5-,Far higher than the current engineering practice measurement of AC electrical signal accuracy.