A novel scheme for three-phase grid-connected photovoltaic (PV) generation systems is presented in this paper. The proposed scheme is based on two insulated strings of PV panels, each one feeding a standard two-level three-phase voltage source inverter (VSI). Inverters are connected to grid by a threephase transformer with the open winding configuration on inverters side. The resulting conversion structure performs as a multilevel power active filter, doubling the power capability of a single VSI with given current rating. An original control method has been introduced to regulate the dc-link voltages of each VSI. The proposed algorithm has been verified by numerical simulations with reference to different operating conditions. The results confirm the effectiveness of the whole conversion structure.
Multilevel Power Conditioner for Grid-Connected Photovoltaic Applications
GRANDI, GABRIELE;ROSSI, CLAUDIO;CASADEI, DOMENICO
2008
Abstract
A novel scheme for three-phase grid-connected photovoltaic (PV) generation systems is presented in this paper. The proposed scheme is based on two insulated strings of PV panels, each one feeding a standard two-level three-phase voltage source inverter (VSI). Inverters are connected to grid by a threephase transformer with the open winding configuration on inverters side. The resulting conversion structure performs as a multilevel power active filter, doubling the power capability of a single VSI with given current rating. An original control method has been introduced to regulate the dc-link voltages of each VSI. The proposed algorithm has been verified by numerical simulations with reference to different operating conditions. The results confirm the effectiveness of the whole conversion structure.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.