Experimental verification of single phase utility interface inverter based on digital hysteresis current controller

Current control of single phase utility interface is one of the problems because current reference contains frequency components. Several methods have been proposed to overcome this problem such as deadbeat control, inner model method and so on. Hysteresis control is one of the current control method which can realize robust current controller with simple hardware. On the other hand, LC output filter is required in some cases. In this case, a simple hysteresis control may cause oscillations or current error due to LC filter. Authors have proposed a new current control method suitable for single phase utility interface inverter using digital hysteresis controller with PI controller and state feedback. In this paper, experimental verification of the proposed method will be done under connecting utility using fully digitalized controller. The developed fully digitalized controller is realized by FPGA based controller. Then the effectiveness of the proposed method will be discussed.