Study of four-phase power transmission systems

Multi-phase power transmission is an important method to increase the power density transmitted. The principle of a new four-phase transmission is proposed, and the general characteristics of four-phase overhead power transmission lines are discussed. Four-phase overhead transmission lines have special advantages in multi-phase transmission lines, because of the good symmetry and the simple structure of the lines and poles. Under the same condition of parameters, four-phase transmission lines can increase the transmission capacity by 33.3%, compared with three-phase lines. As the land width occupied by four-phase lines decreases, the capacity transmitted in unit land width by four-phase lines increases by 41.0-88.7%, and the economical and environmental benefits are much more notable. The reliability and transient stability of the transmission system may be improved, because two adjacent phase conductors of four-phase transmission lines can operate. Attention from the power industry is expected