Abstract: Application of the four-circuit on one tower transmission technology is an effective way to solve the corridor shortage problems for transmission lines, and to improve transmission capacity and build the resource-saving power grids. Based on UHVAC-dedicated technological research results, a study was made through theoretical analysis and numerical calculation on the tower types of 1 000 kV and 500 kV four-circuit AC transmission lines on the same tower. Based on the experiences of EHV four-circuit AC transmission technology, two typical tower structures were analyzed in terms of electromagnetic environment, lighting performance, icing verification and economy. A reasonable tower type was selected, and the tower head layout scheme was proposed, which can provide a reference for tower design of 1 000 kV and 500 kV four-circuit AC transmission lines.

Key words: four-circuit transmission lines on one tower, electromagnetic environment, lightning performance, icing verification, tower head layout