A Conversion Structure Based on a Dual T-type Three-Level Inverter for Grid Connected Photovoltaic Applications

A conversion structure based on a multilevel inverter for grid connected photovoltaic applications is presented. The structure includes two T-type three-level inverter, which are connected to grid by a three-phase transformer with the open winding configuration on inverters side. It also includes two insolated strings of PV panels that are feeding each one of the T-type inverters. The obtained multilevel inverter allows obtaining fifty seven different voltage vectors. To control the dual T-type three-level inverter is used a sliding mode controller and a vectorial modulator. The proposed structure is analyzed and verified by numerical simulations. From the obtained results it is possible to confirm the effectiveness of the proposed structure.