Research On Power Quality Monitoring Of Steady State And Harmonic Treatment Based On DSP

With the increasing of power load, especially the widely use of nonlinear load in powergrid, power quality has been seriously polluted. But the strong and smart grid of state has aincreasing requirement to the electric energy quality. A green, energy-saving, environmentalprotection grid system is imperative. To solve this contradiction, power quality monitoringand the harmonic management is indispensable. Power quality monitoring which is real-time,global and the highly intelligent, can effectively prevent damage caused by power qualityby monitoring the power quality of grid. Harmonic governance is the basic way ofpurification of power grid.Both power quality monitoring and harmonic governance exist sideby side and play a part together not a single one can be omitted.They improve the reliabilityand flexibility of power grid power supply and the energy utilization efficiency.The first and second chapter of this paper mainly elaborate the background andsignificance of the research and introduce the definition and allowed limits of power qualityin the national standard, then describe the present research situation and development trend ofpower quality monitoring and harmonic treatment. Finally, the monitoring of the parametersof power quality is analysised.The third chapter of this paper basically design the steady-state power quality monitor,including design of hardware circuit and algorithms. Hardware system is designed separatlyin modular, including the power board, transformer board, the mainboard.The core circuit ofeach module is interpreted in detail. The core algorithms of the device is analysisedthoroughly. Finally, Each monitoring parameters of the prototype is tested systemly,andanalysis of measureed data shows that monitoring index of each phase conform to the nationalA grade error criterion. The sources of the error is analyzed.Monitoring device and the main circuit of voltage parallel APF in three phase three wiresystem is designed basically in the fourth and fifth chapter of this paper. Monitoring devicewhich is divided into two levels totally is designed by layer and by module. The upper layer isSVG device, PWM board, mainboard, and relay board are designed there. Steady-state powermonitor which is designed in the third chapter is used in public network monitoring of thelower layer. Finally, experiment of harmonic elimination of the prototype is carried in thescene. The compensation characteristic and compensation effect of the prototype aredconcluded through a large number of experimental data analysis. The sources ofcompensation error of the prototype are analysed in detail.