Precise digital control method with multi-rate deadbeat control for single phase utility interactive inverter with FPGA based hardware controller

A new current control method for the utility interactive inverter based on multi-rate deadbeat control with FPGA based hardware controller is proposed. Multi-rate deadbeat control improves the tracking accuracy to the reference compared with the conventional single rate deadbeat control. As a result, superior characteristics were derived with very small LC filter component. Also to utilize the capability of FPGA based hardware controller, all the control circuit for the proposed current control method using voltage deadbeat control and PLL control with quasi-dq transformation are implemented in FPGA based hardware controller. The design concept of the controller is also described, and the advantages and the disadvantage are discussed through simulations and experiments.