Research And Design Of On-line Power Quality Monitoring System

With the continuous expansion and upgrading of the domestic power system, the powerquality problems are got more and more attentions. Power quality problems affect the powercompany or the user of electric power and electronic equipment normal operation, reducingthe service life of the equipment, resulting in serious damage to the equipment.Power qualityproblems are increasingly affecting the normal production and people’s daily life.This paper studies the problem of power quality and power quality monitoring researchbackground, as well as the domestic development present situation. Current power qualitymonitoring devices have problems such as flexible configuration and hard to upgrade. Toimprove these problems, the design of new high performance on-line monitoring system ofpower quality is given. The main work includes the theoretical research, the software andhardware design.The thesis mainly researches on power quality parameters analysis algorithm, focusingon the harmonic algorithm and voltage flicker algorithm.With analysis of the traditional IECalgorithm, Harmonics detection algorithm takes the weighted window treatment, interpolatedcorrection and other methods to effectively improve the spectrum leakage and fence effectcaused by the non-synchronous sampling; the Goertzel algorithm as a replacement for theFFT algorithm is used in harmonic calculation; Based on the basic principles of the IECflicker meter, The flicker algorithm gives the digital processing of the IEC flicker analyzermodel.Through MATLAB simulation, the practical performance of the algorithms are proved.Hardware platform is dual-core processing,using the DSP TMS320VC5509A as thecomputing core and ARM S3C2440A as the control core. The two cores work togetherthrough the HPI interface, to ensure that the system has high performance, multi function andreal-time. The design uses the8-channel simultaneous sampling AD7606and reliablehardware synchronization circuit, to effectively restrain the non-synchronous sampling.The software of multi-task operation and scheduling of the power data measurement anda variety of algorithms is developed on DSP/BIOS real-time systems.ARM software is mainlybased on the the WinCE5.0systems and the HPI hardware drivers is developed. And the useof Labview Touch Panel Module realize the man-machine interface of the system, as well asthe network communication function.With user-friendly man-machine interface and good expansibility, the system applies toboth the field measurement and the long-term on-line monitoring.