Abstract: As the malfunction happens in the Ship Power System (SPS), tripping operation itself is a large disturbance to the system, which may causes undesired system instability if it is not operated at appropriate place and time. This thesis is devoted to detailed digital simulation of one defined SPS to disclose effects of breaker tripping operation to the system. Modeling of the generator, cables, transformer and load are discussed using PSCAD/EMTDC. Since the detail parameters is unavailable, the exciter and governor model of the generator are tested with typical parameters, which is verified to meet the technical requirement of SPS defined by r elevant military standards. Motor model using nominal parameters rather than detail electric parameters is also testified to be accurate. Based on the model established, the effects of generator trip to SPS stability i s studied with typical system conditions. Load shedding measure is proposed and verified by detailed digital simulation, which is proved to be effective.