Analysis and design of an isolated three-phase micro-inverter with integrated energy storage
Name: FELIPE DA CUNHA BRANDÃO
Publication date: 12/05/2023
Advisor:
Name |
Role |
|---|---|
| WALBERMARK MARQUES DOS SANTOS | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| LUCAS FRIZERA ENCARNAÇÃO | Internal Examiner * |
| TIARA RODRIGUES SMARSSARO DE FREITAS | Internal Examiner * |
| WALBERMARK MARQUES DOS SANTOS | Advisor * |
Summary: In order to achieve the decarbonization targets and to combat climate change, it is necessary to reduce the use of fossil fuels and increase energy production from renewable sources. Due to being silent, easy to install and maintain, photovoltaic (PV) systems have experienced great growth over the last few years. The microinverter, as the interface between the PV array and the power grid, has become increasingly popular due to its potential to achieve high reliability, individual power optimization and provide considerable system flexibility. Within this context, this work presents a two-stage and three-port microinverter for photovoltaic applications operating connected to the three-phase electrical grid (three-wire). One port accommodates the photovoltaic panel, the other port accommodates a storage system and the third port is connected to the conventional electrical network. The storage system (which can be a battery or supercapacitor) works as a backup source to compensate for energy fluctuations and store excess energy generated by the photovoltaic
panel. A DAB converter is used to provide galvanic isolation and maximum
power point tracking of the photovoltaic panel. The inverter connected to the mains is a VSI. Tests are performed on the system controlling the inverter with different strategies ranging from the classical linear approach to the Model Predictive Control - MPC. The aim is to evaluate the influence of the strategies on the THD of the output current. An analysis of the influence of the parametric variation of the circuit on the THD is also carried out. The studies were carried out by computer simulations considering a 400W microinverter.
