An Adaptive Passivity-Based Controller for Boost Converter Supplying Constant Power Load

This paper presents a robust and adaptive passivity-based controller (PBC) to regulate the output voltage of a DC-DC boost converter supplying a constant power load (CPL) paralleling with a resistor in dc microgrids which exhibiting limit-cycle behavior when CPLs dominate the load. Based on Lyapunov's theory, the limit-cycle behavior is analyzed in detail. This instability effect caused by CPLs has been attempted to be removed by introducing PBC, but the previously proposed PBC is not robust. The aim of this paper is to propose a new PBC with a certain degree of robustness. To deal with the steady-state error problem caused by the input voltage variation, the nonlinear disturbance observer (NDO) is added to PBC for disturbance estimation. The proposed PBC strategy is robust when dealing with load variation. The steady-state error caused by source variation is eliminated by introducing the estimated value of NDO into the design of PBC. The simulation results are provided to verify the effectiveness and robustness of the proposed control strategy.