Modeling and control of a grid tied differential Cuk Inverter

This Paper presents two different control strategies for a grid tied Differential Cuk Inverter. It shows the operating principle of the converter, a classical PI controller and a nonlinear controller based on sliding surfaces. A detailed analysis of the dynamics of the inverter is performed that is used for the design of the controllers. The classical PI controller is designed, based on the small signal average model of the inverter, and for the sliding mode controller, the nonlinear system is approximated to a linear system with a disturbance. For testing and comparing the performance of the controllers, simulations are accomplished, with changes in the phase and amplitude of the reference current and the input voltage. The simulation shows results comparing the overshoot, the settling time and the steady-state error of the inverter.