Design And Research Of Power Quality On-line Monitoring System

In recent years, the power quality problems play an important role in more and more power departments and their consumers day by day. In-depth analysis and study of power quality problems, the establishment of power quality on-line monitoring system and clearing up of the two sides'the responsibility and obligation are the prerequisite to improve the power quality to meet the development of production and demand. Also, it is necessary to be adapted to the competition in industry market and sustainable development.In this paper, the concept, classification and its hazards and the causes of power quality are introduced, and then explored the issues of power quality monitoring of the background and significance of the research at home and abroad with the development trend. This paper presents a Power Quality Monitoring System based on the virtual instrument. The measurement algorithm about some of the main power quality indicators (frequency, harmonics, voltage fluctuation and flicker, non-stationary signals), was analyzed. Monitoring system uses software tracking to measure frequency, saving hardware costs and achieves a synchronous digital sampling, accurate calculation of RMS, harmonics and other power quality indicators. For Flicker and transient disturbances caused by nonlinear loads, in this paper, it detailed On-line monitoring design. And the simulation and experiments show that using digital filtering and mathematical statistical method of monitoring voltage flicker is effective and rational; it also shows that use Mallat algorithm can be fast and accurate identification and location transient power quality issues.This paper has developed the power quality on-line monitoring systems based on the virtual instrument, and completed the selection of hardware devices and the design of software module. This system can test the voltage and current on-line, collect the real-time data, and use the selected method to calculate and analyze the necessary power quality indicators. This system has a friendly man-machine interface, data storage, and it has extensive upgrading of the expansion of space. In laboratory test, the measurement accuracy achieved relevant national standards, and the performance fully meets the needs during power quality monitoring.