Constant Voltage Control Using Fuzzy Logic Controller (FLC) to Overcome The Unstable Output Voltage of MPPT in DC Microgrid System

Research and development on DC microgrid is increasingly being done recently. This development aims to reduce or even replace the electrical energy generated from fossil energy. Therefore, DC microgrid is present to be the solution of future electric energy by using renewable energy. Many energy sources are used in microgrid systems, but the most widely used is photovoltaic (PV) to convert solar energy into electrical energy. Unfortunately, the system using PV is very limited in its usage time, so it needs a backup energy source to help with the power needs of the load when there is no sun. In addition, most PV systems also use maximum power point tracking (MPPT) using an algorithm to maximize power from PV. The use of MPPT in PV system has a positive impact that can improve the efficiency of power on microgrid but on the other hand this MPPT system can cause problems that is unstable voltage and can exceed DC bus voltage. Therefore it needs constant voltage control to keep the voltage on the DC bus remains stable and located at a set point that has been determined. So in this research will propose fuzzy logic controller (FLC) to keep the voltage on DC bus remain constant. The FLC will be applied to the converter buck while the MPPT control using the flower pollination algorithm (FPA) will be applied to the coupled inductor SEPIC converter.