Thomas, Laurence J. (2010-12). Prognostic Control and Load Survivability in Shipboard Power Systems. Master's Thesis. Thesis uri icon

abstract

  • In shipboard power systems (SPS), it is important to provide continuous power to vital loads so that their desired missions can be completed successfully. Several components exist between the primary source and the vital load such as transformers, cables, or switching devices. These components can fail due to mechanical stresses, electrical stresses, and overloading which could lead to a system failure. If the normal path to a vital load cannot supply power to it, then it should be powered through its alternate path. The process of restoring, balancing, and minimizing power losses to loads is called network reconfiguration. Prognostics is the ability to predict precisely and accurately the remaining useful life of a failing component. In this work, the prognostic information of the power system components is used to determine if reconfiguration should be performed if the system is unable to accomplish its mission. Each component will be analyzed using the Weibull Distribution to compute the conditional reliability from present time to the end of the mission. To determine if reconfiguration is needed, all components to a given load will be utilized in structure functions to determine if a load will be able to survive during a time period. Structure functions are used to show how components are interconnected, and also provide a mathematical means for computing the total probability of a system. This work will provide a method to compute the conditional survivability to a given load, and the results indicate the top five loads that have the lowest conditional survivability during a mission in known configuration. The results show the computed conditional survivability of loads on an all electric navy ship. The loads conditional survivability is computed on high/medium voltage level and a low voltage level to show how loads are affected by failing components along their path.
  • In shipboard power systems (SPS), it is important to provide continuous power to

    vital loads so that their desired missions can be completed successfully. Several

    components exist between the primary source and the vital load such as transformers,

    cables, or switching devices. These components can fail due to mechanical stresses,

    electrical stresses, and overloading which could lead to a system failure. If the normal

    path to a vital load cannot supply power to it, then it should be powered through its

    alternate path. The process of restoring, balancing, and minimizing power losses to loads

    is called network reconfiguration. Prognostics is the ability to predict precisely and

    accurately the remaining useful life of a failing component. In this work, the prognostic

    information of the power system components is used to determine if reconfiguration

    should be performed if the system is unable to accomplish its mission. Each component

    will be analyzed using the Weibull Distribution to compute the conditional reliability

    from present time to the end of the mission. To determine if reconfiguration is needed, all

    components to a given load will be utilized in structure functions to determine if a load

    will be able to survive during a time period. Structure functions are used to show how

    components are interconnected, and also provide a mathematical means for computing

    the total probability of a system. This work will provide a method to compute the

    conditional survivability to a given load, and the results indicate the top five loads that

    have the lowest conditional survivability during a mission in known configuration. The

    results show the computed conditional survivability of loads on an all electric navy ship.

    The loads conditional survivability is computed on high/medium voltage level and a low

    voltage level to show how loads are affected by failing components along their path.

publication date

  • December 2010