Implementation of Grid-connected Single-phase Inverter Based on FPGA

Exploiting the capability of an FPGA, a digital current controller of a single-phase inverter for grid interface is designed and implemented. A Proportional and Resonant (PR) controller realized in a parallel structure in the FPGA is used to reduce the harmonic current to ac grid. The harmonic compensators based on the PR controller are implemented up to the 19th order. The size of the LCL filter has been extremely reduced because the switching frequency is increased to 100 kHz. The validity of the FPGA based grid-connected single-phase inverter has been evaluated by experimental results.