Design Of Intelligent Time-Frequency Domain Data Acquisition Card Used For Power Quality On-line Monitoring

The development of computer technology makes data acquisition and analysis more and more convenient,powerful data processing capabilities and high-speed data communication interface makes the computer data acquisition and analysis and the best choice.With the participation of the computer,people’s ability to capture and analyze data is getting stronger and stronger,and the labor paid is less and less efficient.This paper mainly designed a set of multi-function data acquisition system,hardware acquisition board design and software PC design two parts.Hardware for the ARM microcontroller as the core of the data acquisition and signal generation board,the software for the use of LABVIEW design of the four virtual instruments,both through the USB universal serial bus to communicate with oscilloscope,signal generator,spectrum analysis and Frequency characteristic test function.The sampling rate of the board data acquisition is 400 KSa,the vertical resolution is 12 bits,the storage depth is 20 K bytes,and the input signal amplitude is-10 V ~ + 10 V.The waveforms of the signal are square wave,triangular wave,sine wave and sawtooth wave,Amplitude of 10 V,the highest frequency of 600 kHz,under the control of the host computer software can be up and down translation.The host computer uses LABVIEW to design the four time-frequency virtual instrument functions.The oscilloscope has the measurement function of frequency parameters such as frequency,amplitude,duty cycle,peak-to-peak value and rise time.The signal generator can be intuitively adjusted in the host computer The required parameters of the waveform;spectrum analyzer for spectrum analysis,while the signal frequency and signal distortion can be measured.