Feedback Linearization based Direct Power Control of a three-phase grid-connected inverter with online parameter update

Feedback linearization based direct power control for a three-phase grid-connected inverter has been presented in this paper. An online parameter update scheme based on model reference adaptive system has been implemented in this paper to achieve better tracking performance. Power transferred between two ac sources is a non-linear function of voltage and current therefore, feedback linearization based control architecture makes the overall closed loop system linear and easier to design a compensator. However, the overall controller architecture is a function of the filter parameters therefore, a methodology to estimate the filter parameters and online update the controller gains is presented in this paper. Two fictitious quantities $A=v\times i^{*}$ and $B=v^{*}.i$ are utilized to estimate the filter parameters. The proposed architecture is verified via computer simulations based on MATLAB/Simulink and PLECS domain to check the efficacy for various important case studies.