Design Of Real-time Dynamic Amplitude Measurement System Based On FPGA

Fast and accurate measurement of amplitude in electrical signal parameters has always been a research hotspot in the field of information processing.High-accuracy and fast signal amplitude measurement provide scientific basis for energy metering and power quality analysis,fault diagnosis,power harmonic suppression and compensation,and digital communication.Based on the full investigation of the domestic and international amplitude measurement methods,the FFT algorithm combined with FPGA is applied to the second-frequency component extraction of the Motion Stark Diagnostic(MSE)polarization angle measurement.According to the two key design indicators of MSE diagnosis better than 5% polarization angle measurement accuracy and less than 10 ms polarization angle measurement period,the main work of the thesis is as follows:1)Based on the understanding of the principle of FFT algorithm,this paper analyzes its problems and solutions in spectrum analysis.It simulates the MSE diagnostic signal in Matlab and verifies the method of improving spectrum leakage.The system design based on FPGA and using FFT algorithm to obtain signal amplitude measurement is given.The system hardware design is introduced from ADC,DAC and FPGA respectively.The program design of the system is completed according to the windowed FFT algorithm,and the correctness of the timing is verified from the simulation analysis of each functional module.2)Based on the analysis of FFT algorithm,an improved FFT algorithm is proposed,which solves the time resolution problem of FFT algorithm.The paper introduces the implementation of the improved FFT algorithm,and verifies the feasibility of the algorithm to extract the amplitude in Matlab.Then the program design based on FPGA and using improved FFT algorithm is given,the system running flow is analyzed,and the correctness of the timing simulation verification program is performed in Modelsim.3)Laboratory testing and field testing of the two amplitude extraction methods,the test results meet the key requirements of MSE diagnosis,It is more intuitive to obtain the amplitude based on the improved FFT algorithm and greatly improve the time resolution of the amplitude measurement.