Design Of Power Quality Monitoring System

With the development of power electronies，switehing power devices such as thyristorsbeeome widely used in high-power industrial oeeasions’application. These non-linear loadshave become the power system’s main harmonic sources and seriously reduce the quality ofpowe rgrid. At the same time, the precision electronic instruments based on computer,microcontroller are used widely and become more and more sensitive to the quality of powersupply. A stricter demand for power quality, so that power quality problems and solutionsgradually become a research hotspot. Power quality information detection and analysis is theprecondition to monitor and control the power quality.So it has significant theoretical andpractical value for ensuring the safe operation of power systems and safe use of theconsumers.Firstly, research status in the field of power quality monitoring at home and abroad isanalyzed. The common concepts and algorithms of power quality monitoring are presented,and power quality monitoring system hardware and software are designed. And then generalframework of the electric power quality monitoring system is analyzed. The digital signalprocessor (DSP) TMS320F2812is choosed as the master chip, At the same time the system’shardware and software are designed. The FFT algorithm is used in real-time monitoring.Andonce found harmonic overrun, then start active power filter to inhibit harmonic.The active power filter (APF) is developed rapidly these days, which is a dynamicharmonic depressed and reactive compensation equipment.The related research has becometopic. The parallel active power filter APF is simulinked on on the Matlab7.8. The controlsystem adopts double loop control strategies: voltage outside loop and current loop.Theharmonic current detection method based on instantaneous reactive power theory is detailedlyintroduced. The simulation results show that APF has good function of harmonic control.