Research On The Grid-connected Technology And Energy Management Platform For Photovoltaic Micro-grid

Photovoltaic generation is a technology which converts solar energy to electricalenergy, so it has great reserves and good markets. The photovoltaic micro-grid ismade up from multiple distributed generators (DG), and it has larger capacity andhigher reliability compared with the single DG. So the photovoltaic micro-grid is veryimportant to be researched. There are many distributed generators in photovoltaicmicro-grid, so the energy management and control platform which used to monitorthe running states of each DG is very import to improve the running efficiency.Based on the power curves of photovoltaic arrays (PV), the improved maximumpower point tracking (MPPT) method is developed in this paper. The simulationresults show that the MPPT algorithm in this paper has higher speed and accuracy. Atthe same time, the single-phase and three-phase photovoltaic grid-connected invertersare analyzed in this paper. The simulation results show that the inverters have goodwaveforms and high efficiency. Further, an improved phase locked control algorithmwhich based on the synchronous coordinate transformation is researched, thesimulation results in Matlab/Simulink show that the phase locked method in this paperhas nice performance.Based on the basic theories of photovoltaic micro-grid, the photovoltaicmicro-grid’s model which composed of synchronous generator, photovoltaic generator,energy storage unit and grid-connected unit is researched and designed in this paper.The AC and DC bus program is used in the model, and the micro grid can achieve thegrid-connected and island operation function. Finally, based on the management andcontrol platform, a series of experiments are conducted. The results show that thephotovoltaic platform can achieve the maximum power point tracking, grid invertercontrol and grid-connected functions.