This paper presents studies on improving the robustness of shipboard dc hybrid power systems. The shipboard power system can be regarded as an islanded microgrid. The objective, in particular, is to reduce the load curtailment when generator failures take place in the islanded microgrid. By applying the basic unit commitment (UC) operation model, the loads can be fully supplied during normal condition. However, a portion of the loads has to be shed if any generator fails. Two approaches are proposed to mitigate the loss of load during and after fault. They are developed by modifying the UC models. These approaches are evaluated for reducing load curtailment under loss of generation. Selected case studies indicate encouraging results that the loss of load can be reduced during and after generator failure. For carrying out the case studies, the optimization model is built on General Algebraic Modeling System (GAMS) platform.