Finite-time Stabilization of Constant Power Loads in DC Microgrids

The large integration of power electronic converters in DC microgrids causes constant power load (CPL) stability issues. This paper proposes a composite finite-time controller for stabilizing a DC/DC boost converter feeding CPLs. The proposed composite controller consists of a finite-time disturbance observer and a finite-time controller. The finite-time disturbance observer estimates the load variation and model uncertainties for accurate voltage tracking. Then a finite-time controller is designed following the finite-time control algorithm, which yields the system stability under large signal disturbances with finite-time convergence. The proposed composite controller not only features fast dynamic performance with accurate tracking, but also ensures large signal stability under large disturbance of CPLs. Simulation and experimental results are presented to verify the proposed strategy.