Digital Control Method for Single Phase Utility Interactive Inverter Using Deadbeat Control with FPGA Based Hardware Controller

A new current control method for the utility interactive inverter based on deadbeat control with FPGA based hardware controller is proposed. In the utility interactive system, the utility line voltage should be included in the system model, so the procedure to derive the discrete time system model is the key point to achieve the accurate control characteristics. In the proposed method, different approaches were applied to derive the discrete model to the utility voltage and the inverter voltage. 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