Slot bottom size has directly effect on conductor abrasion,Chinese Technical Regulation of design for Stringing blocks of overhead transmission lines (DL/T371-2010) clearly states that slot bottom size should be no less than 20 times of the size of conductor to be extended. In this paper, based on effect of slot bottom size on conductor abrasion,the size of slot bottom of stringing pulley is analyzed. Some useful suggestions are given.

The limiting width-thickness ratio of 2A12 angle Aluminum Alloy under axial compression is discussed using guide for design of transmission tower by American society of civil engineers, Chinese Technical regulation of design for tower and pole structure of overhead transmission line (DL/T5154-2002) and Chinese code for design of steel structures (GB50017-2003). The results show that the formula of Chinese code for design of steel structures about limiting width-thickness ratio is reasonable. And there is unreasonable in Chinese technical regulation of design for tower and pole structure of overhead transmission line and guide for design of transmission tower by American society of civil engineers about the formula of limiting width-thickness ratio. Some useful suggestions are given.

Conductor scheme is one of most key issues in the design of the transmission lines project, and it is significant for the construction cost and safe operation of transmission lines project. It can be aslo concluded from analysis on application of existing conductor that the appropriate decrease of number of bundle conductor and increase of the conductor cross-section will reduce lines loss, which has remarkable social-economic benefits. In this paper, the economic analysis of large cross-section conductor is conducted based on ±800kV DC Project. Some useful suggestions are given.

Conductor scheme is one of key issues in the design of the UHVDC transmission project, and it is significant for the construction cost and safe operation of transmission line. It can be concluded from analysis on application of existing conductor that the appropriate decrease in number of bundle conductor and increase of the conductor cross-section will reduce line loss, which has remarkable social-economic benefits. In this paper, the economic analysis of large cross-section conductor is conducted based on UHVDC Project. Some useful suggestions are given.