Using the DC-link capacitor as a rotating inertia in a three phase PV system

This work provides the guidelines to calculate the size of the DC-link capacitor to contribute with additional energy - for a short period of time - than the photovoltaic panel can supply under normal operating conditions. First, a model of a three-phase electric generation system is used that combines photovoltaic panels and an inverter with an LCL filter at network side. In addition, a control algorithm capable of exchanging between two operating modes is implemented. Indeed, the first one is generated by the MPPT and the second one is generated when the grid demands more energy than the photovoltaic panel can generate. The results show that the PV system can provide additional energy - for a short period of time - from the dc link as emulating a large rotating inertia. The results are shown through simulations under standard test conditions (STC).