Natural Aging of Non-Energized Aluminum Conductors
This paper reports the results of a photographic and electrical study of the mechanism by which a new aluminum conductor ages. A systematic approach of monitoring the aging process revealed the movement of water drop location from the top of a new conductor to the bottom of an aged conductor. Through photographic water drop analysis and electrical test results it has been determined that an aluminum conductor, even though not energized, is essentially aged in 4 to 7 months in the environment of northern Indiana, USA. A seasonal effect was found to add up to 5 months to this period.
Influence of aged conductor surface conditions on AC corona-generated audible noise with a corona cage
Relatively few investigations have previously been made on the effects of surface conditions on corona-generated audible noise for the long-term aged ac conductors. In the present work these were investigated by means of comparing audible noise on typical aged conductors with that on new ones. The aged conductors from the ac power transmission lines had been in service for 12, 15 and 20 years, and their surface morphology, composition and roughness had been analyzed in our previous paper. A microphone and sound level meter was employed to measure the audible noise of the aged conductors in a small corona cage. As a result of the much intense corona discharge on the surfaces of the aged conductors, the audible noise of the aged conductors was much higher than the new conductors in dry condition. In wet condition, the corona discharge was found to be become more serious than the conductor in dry condition; hence, the audible noise was about 3 to 5dB stronger than that in dry condition.
Application design of a sun-tracking system
As a very good renewable energy, solar energy gets a lot of countries' concerns. How to improve the efficiency of solar panel is now a hot topic and sun tracking is one of the solutions. In this paper, a servo tracking system using dSPACE DS1104 R&D controller board is designed to improve solar collection efficiency. It combines electro-optical tracking and sun trajectory tracking, and can keep solar panels perpendicular to the sun during daylight hours. In order to reduce the amount of computation, a T-S fuzzy system based sun trajectory tracking is proposed. Because of the seamless connection between dSPACE and MATLAB/Simulink, the development cycle time is short. Experimental results show that the system can track the sun precisely and has higher efficiency.