A design method for a fault-tolerant multi-agent stabilizing system for DC microgrids with Constant Power Loads

Abstract

It is known that DC-power systems containing Constant Power Loads (CPLs) could become unstable under some conditions. This instability phenomenon is due to the interaction between the network structure and the negative impedance created by the CPLs. To ensure the system stability, we propose in this paper a method which permits to design a fault-tolerant stabilizing system for a DC-microgrid with CPLs. First, it consists in the implementation of local stabilizing agents on the CPLs. Then, using a constrained optimization problem, a method to design the stabilizing system is proposed. It permits to consider many fault cases as system reconfiguration or agent failure. To illustrate the method, it is implemented on test bench and experimental results are given to confirm its efficacy. NOMENCLATURE Ȝ eigenvalues of the matrix A ଙsmall-signal variations of operating (equilibrium) point of i-th optimization algorithm constraint CPL i operating power (defined by the system user) CPL i stabilizing power power absorbed by the CPL i (= )

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