| The traditional power measuring system is an integration of various kinds of measuring instruments with huge volume, solid function module, which can't meet complicated, real-time, many-parameter requirements gradually. With rapid progress of electronic technology, computer technology and network technology, new testing theory and method, new instrument structure is appearing. Function and application of measuring instruments has changed a lot. One marked characteristic is appearance and development of Virtual Instrument with the advantage of flexible programming, user-defined, powerful data processing and analysis function, short development period and so on, which is a great new production of computer technology and instrumentation technology. It has wide application in the measure and control of power system. Therefore, a measuring system of power based on virtual instrument is designed in this paper. It can measure and analyze power parameter, such as voltage, current, frequency, phase difference, harmonic and voltage flicker signal.Firstly, basic conception, structure and development of Virtual Instrument, also development platform LabVIEW and programming language are introduced generally. Definition of power parameters are introduced, which measuring methods are studied. In voltage flicker signal analysis, measurement of voltage flicker using wavelet transform with synchronous detection is proposed. It has been proved that this method can detect voltage flicker exactly, by which not only break time and degree, but also frequency and amplitude of modulated wave is detected exactly by simulation.Secondly, the structure of signal conditioning is expounded particularly. Then, the whole frame and function modules of software design, the debug method and simulation result of the system is given.At last, the shortage of the system is given.The system can measure and analyze signal in real time, manage history data and display waveform with simple operation and strong analyzing function.
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