One Cycle Control Applied Photovoltaics on Autonomous Systems in a DC Microgrid
A control cycle, Photovoltaic Systems, Converters, MPPT, Microgrid.
The integration of units with primary energy sources with energy storage and cargo, is expected to play a promising role in the future for the supply of electricity. The networking on such units providing medium and low voltage forms a called microgrid system. The distributed energy sources are the basic units for storage and distribution in microgrids. These sources can be a hybrid type which includes a primary energy source and storage simultaneously. A hybrid type of unit is proposed in this paper consists of a buck-boost converter DC-DC that tracks the maximum power supplied by a photovoltaic panel, a DC-DC boost converter that regulates the DC bus voltage microgrid and a buck converter DC-DC bidirectional -boost that controls the flow of energy in the drive, loading or unloading a battery bank. The control of these converters should consider the protection of battery against voltage transients and spikes, as well as the protection of loads connected to the main bus microgrid when the battery supplies the stored energy. Conventional control techniques used in converters of these units use the modulation pulse width which has the disadvantage of producing undesirable transient due to the slow response to changes in the system input or the loads connected to the main bus microgrid. These transients are likely to damage other loads and batteries that are connected to the main bus microgrid. The cycle control technique has been used in conjunction the switching converters to allow a rapid response to transient without overshoots and zero steady-state error. The objective of this work is to use this technique in controlling these converters in order to quickly track the maximum power point of the photovoltaic panel, charge the batteries when they are discharged, and provide battery power to the loads when needed, ensuring protection of the battery and the loads connected to the microgrid.