Inner control loops approach to control the islanded photovoltaic microgrid

The intermittent character of the photovoltaic generator, power electronic converters and load dynamic are the main factors leading operation instability in islanded microgrids. The necessity of the immediate control within the micro-source is very important since it impacts the interaction between micro-sources in the microgrid. This control level must be characterized by a fast and accurate response in order to control the operation point of the photovoltaic generator of the microgrid, and also the injected currents into the microgrid, as well as the amplitude and the frequency of the voltage at the photovoltaic connecting point at AC side. However, its performance depends on the control structure and the connecting mode of the photovoltaic generator. In this present paper, we propose a new structure of the internal control applied in islanded photovoltaic microgrids. It advocates the use of the close control multi-objective controller which is developed and implemented with Matlab/Simulink. Accordingly, the simulation results obtained show that this control approach improves the stability operation of the islanded microgrid while allowing maximum power transfer from DC to AC side.