<![CDATA[This paper proposes an interpolation-based robust tracking control strategy for an LC-filtered three-phase inverter operating under parameter uncertainties and input constraints. Conventional LMI-based robust controllers are typically synthesized using a single set of controller gains, resulting in a trade-off between transient performance and actuator constraint satisfaction. This work addresses this limitation by introducing an interpolation-based robust control strategy that combines aggressive and conservative controllers through a recursive interpolation algorithm. The proposed method employs two robust tracking controllers synthesized using LMI optimization. The first controller is designed with aggressive feedback gains to achieve fast voltage tracking and superior transient performance, whereas the second controller adopts more conservative gains to enlarge the feasible operating region and ensure input constraint satisfaction. During operation, the feasibility of the control input generated by the tight controller is evaluated first. If the input satisfies the prescribed actuator constraint, the tight controller is applied directly. Otherwise, a recursive interpolation algorithm is activated to generate a feasible control input by combining the outputs of the tight and loose controllers. This strategy preserves the fast dynamic response of the tight controller whenever possible while ensuring that the applied interpolated control input satisfies the prescribed actuator constraint under demanding operating conditions. The effectiveness of the proposed approach is validated through comprehensive MATLAB simulations under nominal and uncertain operating conditions. Simulation results demonstrate the effectiveness of the proposed method for digitally controlled LC-filtered three-phase inverters operating under parameter uncertainties and actuator constraints.]]>
