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Kaohsiung, Taiwan

Su C.-L.,National Kaohsiung Marine University | Lin K.-L.,National Kaohsiung Marine University | Chen C.-J.,CSBC Corporation
IEEE Transactions on Industry Applications | Year: 2016

The medium-voltage dc (MVDC) distribution system is a new shipboard power distribution technology that has been extensively discussed and studied by many shipbuilding corporations and ship-owners in recent years. As different types of power converters and ac and dc power distributions simultaneously involved in the system, the system performance for different connections of generators to MVDC converters under varying steady-state operating conditions is essential and important in the design stage of the electrical power distribution system. This type of problem can be analyzed by performing power flow studies. This paper aims presenting a methodology for power flow studies in ship MVDC distribution systems for system planning purpose. A power flow model of the power converters in steady-state is derived to consider medium and low voltage characteristics of electric power system on this type of ship. An ac/dc power flow solution approach then is developed to incorporate ac-system and dc-system models and the ac/dc interface buses in the analysis for determining an appropriate connection of generators and MVDC converters and power converter setting values. Test results of two alternatives for the direct connection of generators to MVDC converters under varying steady-state operating conditions are presented and compared to determine the proper generator-power converter scheme. © 1972-2012 IEEE.

Su C.-L.,National Kaohsiung Marine University | Lan C.-K.,Jih Yu Fishery Company | Chou T.-C.,National Kaohsiung Marine University | Chen C.-J.,CSBC Corporation
IEEE Transactions on Industry Applications | Year: 2015

A multiagent-based feeder automation system is developed for the service restoration of power systems in a navy ship after fault contingencies. In the system, power-electronic-building-block agents of the multiagent system (MAS) are used to derive the proper restoration plan after the faulted location is identified and isolated. To assure that the restoration plan complies with operation regulation, heuristic rules based on standard operation procedures of the shipboard power system (SPS) are included in the best first search of the MAS. Two control schemes for SPS restoration are investigated, and their performances are evaluated and compared using a discrete event simulation technique with respect to restoration time. For fault contingency when the capacity reserves of supporting feeders are not enough to cover the fault restoration, the load shedding strategy is derived for the MAS to restore service power to as many key loads as possible. A navy SPS with 72 feeders is selected for computer simulation to demonstrate the effectiveness of the proposed methodology. The study concludes that, to cover feeder automation functions, a MAS with distributed processing capability provides better reliability performance than the centralized control. © 2015 IEEE.

Su C.-L.,National Kaohsiung Marine University | Weng X.-T.,National Kaohsiung Marine University | Chen C.-J.,CSBC Corporation
IEEE Transportation Electrification Conference and Expo, ITEC Asia-Pacific 2014 - Conference Proceedings | Year: 2014

Applications of fuel cells (FCs) to ship power systems have been investigated due to their characteristics of low emission, high efficiency, low vibration, and low noise. Dynamic response is a problem when FCs are installed in ships as power sources. To make the system secure and stable, a methodology for power generation controls of FCs/energy storage hybrid ship power systems is proposed in this paper. The mathematical model of active and reactive powers regulation of the hybrid power system is derived. The model is then applied and integrated into dynamic models of proton exchange membrane fuel cells (PEMFCs) to enhance the system dynamic response. A modified practical ship power system under different operating conditions is selected for computer simulations to ensure and demonstrate the performance of proposed method. © 2014 IEEE.

Lee S.-K.,Abs Consulting | Yu K.,Abs Consulting | Tseng R.K.-C.,CSBC Corporation
Proceedings of the International Offshore and Polar Engineering Conference | Year: 2012

Slamming phenomenon commonly occurs when a ship navigates in rough seas. Depending on the relative velocities between the ship and the free surface and depending on the size of the slamming area, the slamming impact load can be significant, both locally and globally, and becomes a dominant factor in hull scantling determination. In addition to the hull slamming load, the now popular adoption of energy-saving devices (ESDs) in the stern area means the hydrodynamic load associated with the stern slamming situation on ESD also becomes an issue in design. In energy-saving propulsion configurations, the structural integrity of ESD is important because a damaged ESD can result in increased propulsive energy-loss. An accurate estimate of hydrodynamic loads in slamming situations is still a challenging topic as it involves many complex physical phenomena simulations such as large amplitude ship motion, non-linear breaking wave and transient impact load. In this study, an overset grid Computation Fluid Dynamics (CFD) methodology with level set function formulation for violent free surface simulation is adopted to study the hydrodynamic loads due to bow and stern slamming for a containership fitted with energy-saving rudder fins. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE).

Cheng H.-J.,National Taiwan Ocean University | Chien Y.-C.,National Taiwan Ocean University | Hsin C.-Y.,National Taiwan Ocean University | Chang K.-K.,United Ship Design and Development Center | Chen P.-F.,CSBC Corporation
Journal of Hydrodynamics | Year: 2010

Unconventional propellers with end-plate effects such as Kappel propellers get designers' attention due to the environmental concerns and energy saving problems. The computations have been carried out to compare the Kappel propellers and the conventional propellers, and the emphasis is put on the scale effects and the structural performance. The scale-effect is first investigated, and the computational results show that the Kappel propeller has a larger scale effect than the conventional propeller. The structural analysis is then made, and the comparisons of the Kappel propeller and the conventional propeller show that the Kappel propeller suffers from a stronger stress concentration near the tip. © 2010 Publishing House for Journal of Hydrodynamics.

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