Robust Distributed Fixed-Time Fault-Tolerant Control for Shipboard Microgrids With Actuator Fault

Aiming at the problem of frequency and voltage deviation caused by load switching in islanded shipboard microgrids (MGs) under complex sea conditions, this article proposes robust distributed fixed-time fault-tolerant controllers (RDFTFTCs) for the islanded shipboard MG with actuator fault to adjust frequency and voltage as we as achieve accurate power sharing. The actuator fault with biased fault and partial loss of effectiveness fault can affect the performance of the controller, resulting in poor power quality and even instability for the islanded shipboard MG. Therefore, fixed-time observers are proposed to estimate the disturbances caused by the actuator faults and the estimation errors can converge to the origin point within a fixed time. In addition, the estimated average voltages (EAVs) of all distributed generators (DGs) are obtained through distributed fixed-time observers (DFTOs). Furthermore, the RDFTFTCs are proposed to adjust the frequency and voltage, and obtain accurate power sharing within a fixed time independent of the initial operating states of the islanded shipboard MG. The fixed-time stability of the islanded shipboard MG is proven through the Lyapunov function under the proposed RDFTFTCs. The performances of the proposed RDFTFTCs for the islanded shipboard MGs with faster convergence speed and smaller overshoot than that under existing control methods in different circumstances are validated through the simulations in MATLAB/Simulink.