Power management using robust control strategy in hybrid microgrid for both grid-connected and islanding modes

摘要

This paper synthesizes input-output feedback linearization (IOFL) and sliding mode controller (SMC) for a hybrid AC/DC microgrid system under both load variations and parameter uncertainties. The controller is indeed aimed to provide an optimal coordinated performance strategy for power electronic converters in both grid-connected and islanding operating conditions for the power management of the hybrid microgrid. The operation of two DC/ AC converters in the hybrid microgrid is enriched through the dynamic model completion and the control ability promotion in the islanding mode. The initial control functions for power electronic converters are firstly shaped based on applying the IOFL basics to a comprehensive dynamic model. To reach robustness feature for the controller, the sliding surfaces based on the current errors of the power converters are presented. Then, based on the DC-link voltage transfer functions, it is comprehensively evaluated how much the compensators and sliding coefficients can impact the stability margin and tracking capability of the proposed control functions. In addition, to further investigation, several cost functions are attained through the second-order responses of DC-link voltage to obtain optimal values for the controller coefficients. Simulation results in the MATLAB/SIMULINK environment are employed to show the validity of the proposed control technique under load variations, parameters uncertainty and controller coefficients alteration. Also, some comparative simulation results are attained for verifying the superiority of the proposed control technique.