No abstract

No abstract

No abstract

The research on the real time monitoring of the transmission lines is one of the directions for the power grid technologies. Seeing that the terminals of data acquisition system (DAS) of the real time monitoring of the transmission lines had to be located on the top of the tower, they were always in an unattended state, which brought out a protrusive problem of the power supply. This paper described a sort of power supply system featured as a hybrid of capacitors and solar batteries. The design of this power supply device must consider some important factors, such as how to take advantage of solar energy as full as possible and isolate from the high voltage electromagnetic interference. There are also many concrete details in the design of this supply device featured as a hybrid of super capacitors and solar batteries. The capacity of capacitors and solar batteries should also be deliberated to guarantee the maintainable supply at least one week even in the overcast and rainy days. This paper brought out some opinions on the solutions of the problems mentioned above. Related simulations were done to prove the effect of this power supply system of the monitoring system for transmission lines. The result showed that a hybrid energy storing system can play a better performance than single entire energy storing device.

Making CFD with the capability of predicting ship scale design performance, rather than relying on scale model tests will help reduce design costs and provide a greater opportunity to develop more energy efficient ship designs. The key objective of this paper is to perform a fully nonlinear unsteady RANS simulation to predict the ship motions and resistance of a full scale DTMB 5415 ship model. The analyses are performed at design speeds, at a certain Fr number, using in-house computational fluid dynamics (CFD) to solve RANS equation coupled with six degrees of freedom (6DOF) solid body motion equations. RANS equations are solved by finite difference method and PISO arithmetic. Computations have been made using structured grid with overset technology. Simulation results shown that the total resistance coefficient in calm water at service speed is predicted by 2.36% error compared to the related towing tank results. The ship resistance for different scale demonstrated that the current in-house CFD model could predict the resistance in a reasonable range of the EFD data. The comparison of flow field for wave pattern for different scale model were analyzed and discussed.