Power Quality Monitoring And Management System Based On Virtual Instrument Technology And Computer Network Technology

With the development of technology and economy, power quality problems become more and more serious, and its representation form is diversified, so the traditional power quality monitoring equipment can not meet the needs of the modern electricity. In this paper, based on the virtual instrument technology and computer network technology, the power quality parameters monitoring and management system is designed, which is consistent with our national conditions and the smart grid construction requirements.Power quality current research situation, standards and measurement algorithms are studied, and a harmonic and interharmonic measurement method recommended by the IEC 61000-4-7:2002 and GB/T 17626.7-2008 is introduced. The method's measurement errors and its reasons are analyzed, and the corresponding improvements are proposed. The simulation results of variety of typical signals show that the method is suitable for non-stationary signal measurement, while the improved one can ensure the measurement accuracy.Based on the regulations of national standards, the power quality measurement system is developed on the LabVIEW virtual instrument platform. The algorithms of main function modules is detailed, and its programming methods are illuminated by using flow charts and program figures. This system can monitor the power quality parameters, such as voltage deviation, frequency deviation, phase imbalance, harmonics, inter-harmonics, voltage fluctuations and flicker, and voltage sag, and its funtion is plentiful, and its measurement accuracy meets the demand of national standard, and its interface is friendly. Then the concept of "the software is the instrument" is achieved.Using browser/server networking mode and LabVIEW's Web server technology, the remote monitoring of power quality system is done, and the concept of "the network is the instrument" is achieved. Using Access database software and LabVIEW's database access package-LabSQL, a simple and practical power quality parameters database is designed, and then the power quality measurement data management system is achieved.