Four-Phase AC Connections: An Alternative Possibility for the Expansion of Transmission Grids

This paper investigates the economical feasibility of four-phase (4P) overhead transmission lines, considered as a possible alternative to the traditional three-phase (3P) connections. The paper performs an economical comparison between innovative 4P transmission lines and traditional 3P lines, with the goal of evaluating the contests where a 4P connection could become convenient, accounting for different reliability, land occupation, visual impact, energy losses and investment costs.