Knowing How Liquids Fail

Power system equipment like many transformers and capacitors, as well as other types of high voltage equipment, used a liquid insulant for reliable operation. Enough design experience exists to develop dependable equipment even though the fundamental processes in the liquid are not well understood. As cost and environmental concerns stimulate investigations of different materials, however, it is important to improve the understanding of the fundamental processes in liquid breakdown. Recent work at the Center has helped clarify the role of the electric field distribution in the liquid on the breakdown process. This work was reported in the paper, “The Incipient Mode of Streamers in a Dielectric Liquid as a Function of Electric Field,” by M. Kim, S. D. Reedy, and R. E. Hebner. The paper was presented at the 2005 IEEE International Conference on Dielectric Liquids in June. For further information, contact R. Hebner.

Picking Gas Turbines

One desirable feature sought in an all electric ship is to minimize in-hull volume required by the power train. Earlier work within in the Center highlighted the interaction between system efficiency and fuel volume required, the importance of optimal scheduling of turbine use, and the attributes of a high speed permanent magnet generator. A recently published paper by Kent Davey, “Ship Component In-Hull Optimization,” builds on the earlier work to address the selection of turbine sizes. This new optimization, based on anticipated mission profiles, shows that a turbine set consisting of a 50 MW turbine and three approximately 10 MW turbines can save over 600 m³ of fuel compared to the optimized use of four 20 MW turbines. This work was published in volume 39 of the Marine Technology Society Journal.

For further information, contact Kent Davey.