Harmonic Control Research Of Photovoltaic Generation In Microgrid

With energy and environmental problems increasingly prominent, it is generalconsensus of human society that development of low-carbon economy, the construction ofecological civilization and to achieve sustainable development. It become a worldeconomic and social sustainable development strategy that development of cleanrenewable energy. Photovoltaic grid-connected power generation systems which havesome advantages such as high environmental protection, low noise are highly socialfavored. The methods of harmonic compensation of photovoltaic power generation systemwhich is used to improve the quality of power is researched in this paper.Active power filter is the common tool in the field of harmonic suppression. It canremedy the limitation of passive filter. APF has the advantage of initiative, controlled andflexible, having ability of reactive compensation. The unified control strategies betweenthe photovoltaic grid inverters and shunt active power filter is studied on the basic ofanalysis of APF in the dissertation. The main works are as follows:According to the basic work principle of photovoltaic cells, a mathematical model ofthe PV array is derived and its operating characteristics is analyzed. The incrementalconductance algorithm is improved on the basic of solar cell maximum power pointtracking. Then, the basic working principle of the three-phase photovoltaic grid inverterand the active power filter is researched.With the depth analysis of the three-phase instantaneous reactive power theory,i p iqharmonic current detection algorithm is designed, improving the method. designedThe low-pass filter and DC side regulator system is designed, building p q,i p iqand d qMATLAB simulation models.Finally, the unified control strategy is established through the analysis of the samepoint and different points of the grid-connected PV inverter and APF. The synthesisalgorithm of harmonic current detection signal and grid-current signal is designed.Based on PQ control strategy, grid-connected inverter control strategy with APF functionis studied, designing the parameters of the main circuit. MATLAB simulation models ofthe APF, grid-connected PV system, and unified control system is bulit and analysed.