Application of sampled data LQR control scheme for grid tie inverter

In this paper, we present closed loop sampled-data linear quadratic regulator (LQR) based control scheme. Suggested scheme is applied on a practical linear system of a grid tie inverter for tracking a reference signal in the presence of external disturbance. LQR functions on the basis of minimization of a well-defined cost function. Prior knowledge about the external disturbance is utilized by the control scheme. This information is effectively used in defining cost function to minimize the disturbance effects and providing smooth tracking of a reference signal. Through computer simulations, a comparison is also drawn between the proposed sampled-data control scheme and the corresponding continuous-time control scheme applies on third order grid tie inverter plant. We note that sampling time and weighing parameters of the cost function in sampled-data control schemes play pivotal roles in defining its performance.