Precise digital control method with sinusoid based model for single phase utility interactive inverter with FPGA based hardware controller

In this paper, a new current control method for the utility interactive inverter based on deadbeat control with FPGA based hardware controller is proposed. Deadbeat control is one method to ensure the output voltage or current matches to the references at the sampling instant, so adopting this control law to the utility interactive inverter, the response of the system is much improved with small LC filter component compared with the conventional PI control, which results in the improvement of the cost performance of the inverter. Sinusoid based modeling approach was applied to derive the discrete model to the utility voltage and the inverter voltage, precise control accuracy can be derived. 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 advantages and the disadvantage are discussed through simulations and experiments.