Power Electronic Transformer application to grid connected photovoltaic systems

Grid-connected photovoltaic systems utilize static converters which influence the efficiency of the system. The energy conversion depends on the architecture of the converter, different solutions are available and H-bridge multilevel converters seem to be an optimal solution also for the power quality. In the paper is proposed an architecture that includes a power electronic transformer which is practically an isolated high-frequency link AC/AC converter that substitute a conventional transformer. An MPPT control technique is presented and validated by simulation implemented on a photovoltaic system with H-bridge n-levels converter and power electronic transformer. The simulation results confirm that the control is able to effectively track the maximum power point and to stabilize immediately in the new steady-state condition.