Design And Implementation Of Acquisition And Processing Module In Oscillographic Power Analyzer

At present,global attention to energy and power efficiency is increasing.When detecting power signals,traditional power analyzers do not have waveform capture functions,and oscilloscopes cannot perform high-precision power parameter calculations.Functional power analyzer can greatly improve the efficiency of power signal measurement and data analysis.The oscilloscope power analyzer has powerful functions in waveform capture and power parameter analysis.The instrument integrates the rich oscilloscope mode and trigger mode in the oscilloscope,and can perform high-precision parameter calculations at the same time,which can flexibly meet different power signal tests.Scenes.This article is based on the oscilloscope power analyzer project research and development,using FPGA to implement the data acquisition module and power analysis module.The main research is as follows:1.Build an acquisition architecture suitable for power analyzers.It includes common acquisition modes such as common acquisition mode,peak acquisition mode,and high-resolution mode.At the same time,a waveform averaging mode has been added to the instrument,and the maximum number of averagings in this mode can reach 65536.Considering the low sampling rate of the oscilloscope power analyzer,it is difficult for users to observe the details of the waveform,so an equivalent sampling mode was added to the acquisition mode to increase the oscilloscope power analyzer sampling rate to 100 MSPS.2.Realize digital three-dimensional mapping function.This function expresses the probability information of the waveform through the difference of color or brightness,which can effectively improve the waveform capture rate of the oscilloscope power analyzer.This paper has designed a three-dimensional mapping module suitable for oscilloscope power analyzer.It supports up to 4 channels to enable the waveform mapping function at the same time.This function maps multiple channel waveform data in a BRAM module,compared with the existing storage solution can save 71.9% of BRAM storage resources.3.Build a multi-channel synchronous acquisition architecture.When the harmonic content of the input power signal is large,the rectangular wave signal output after passing through the analog comparator will contain a narrow pulse width,and the fundamental frequency measurement of the signal directly using the weekly measurement method or the frequency measurement method will appear relatively Large errors lead to errors in the synchronous acquisition process.In response to this problem,this paper improves the existing frequency measurement method and filters out the narrow pulse width in the output signal of the analog comparator to achieve accurate measurement of the fundamental frequency.The frequency measurement accuracy of this method can reach a reading of 0.05%.4.Realize harmonic analysis function.When the instrument works in synchronous acquisition mode,8192 data points of one channel are used for FFT operation,and the calculation result is sent to the host computer for display.When the fundamental frequency of the input signal is less than 120 Hz,the maximum harmonic analysis of the 250 th order can be performed,and the accuracy of the harmonic analysis can reach the reading × 0.1%,so the oscilloscope power analyzer has a powerful harmonic analysis capability.After testing,the data acquisition module and power analysis module proposed in this paper can reach the design index.