Implementation Of Substation Harmonic Monitoring And Analysis System Based On Virtual Instrument

With the improving of our national economy, various power electronic devices are widely used and also to the power system caused serious pollution, and a variety of industrial production systems for power quality have become increasingly demanding, more and more power quality attention. Therefore, we must understand the power system harmonic sources and their distribution, to take the necessary measures to limit and eliminate harmonics, harmonic suppression and then, at the same time, timely and accurate measurement of power quality parameters of various power systems, industrial production has important guiding significance.Based on the traditional measuring instruments, bulky, relatively fixed function, poor scalability, high maintenance costs, unable to meet the increasingly complex, real-time, require multiple parameters. In this paper, a detailed analysis and comparison of virtual instruments and traditional instruments. Programming language with a graphical virtual instrument technology, standardized instrument hardware and software, graphical user interface, the interface versatility and openness characteristics, using virtual instrument technology and control system design, equipment can shorten development cycles, reduce equipment costs, improve the performance of the instrument. In this paper, power quality monitoring system based on virtual instrument. Virtual instruments are computer technology and instrument technology combined with the product, with programming flexible, customizable, powerful data processing and analysis, etc., have broad application prospects in measurement and control aspects of the power system, the current virtual instrument technology has been in power system widely used.In this system design to the Hall voltage, current sensor, PCI data acquisition card, computer hardware, Lab VIEW software platform for the development, design virtual harmonic analyzer. The original three-phase system voltage and current signals through signal conditioning, data acquisition card by transfer to the computer, and then written in Lab VIEW software program for signal processing.In Lab VIEW software programming, the use of the principle of Fourier analysis of the collected signal analysis and processing, programming common parameters to measure the three-phase AC voltage, three-phase AC RMS current, three-phase power, power factor, phase measurements, 1-50 harmonic analysis measurements(including harmonic amplitudes, the content of total harmonic distortion). While achieving real-time display of the original signal waveform, a spectrogram display and measurement result display. The system also chose to write measurement files, enabling a data storage capabilities, you can always historical measurement data for statistical analysis.Finally, this paper designed and implemented a monitoring system simulation tests and experiments, the test results show that the system can more precise power quality parameters and technical indicators to measure and display, to meet the harmonic substation monitoring and analysis system basic requirements.