Simulation Analysis of Power Frequency Electric Field Around T Connection Tower of Transmission Line
As a new type of line connection, T connection tower has been applied in engineering, but it makes the distribution of electric field around the tower more complicated. In order to determine the electric field distribution around the T-tower and the typical working position of the tower. A 110kV double-circuit AC T-connected tower is taken as the research object. The three-dimensional finite element software COMSOL is used to model the tower, wire and other components. The influence of the arrangement of the wire phase sequence on the electric field distribution is analyzed. The surrounding electric field distribution was simulated. The research results show that the field intensity around the tower and at the typical operation position of the tower are all within the safe range, and the maximum field intensity on the ground is generated on the side of the T-connection line. The calculation results can provide reference for the design of the T-connection scheme of the transmission line. Introduction With the rapid development of the economy, the demand for electricity supply in social production and life is increasing. In the process of new transmission lines, the scheme of adding T-connection lines to the original lines using T-towers has been widely used in the design of transmission lines. At present, the scheme has been well applied in the completed Qingliu-Busan 500kV line project, which reduces the construction cost and shortens the line outage time[1]. The T-tower brings convenience in the design of the transmission line and also increases the complexity of the electric field around the tower. Therefore, research on the electric field distribution around the T-connected tower becomes an indispensable part. A lot of research has been done on the calculation of the electric field distribution around the transmission tower. Common methods for calculating the field strength around a transmission line include the charge simulation method[2,4], the finite element method[5,7], and the moment method[8,9]. In the literature[2], by analyzing the influence of electric field distribution on the ground at 1.5m under different phase sequence arrangements, the conclusion that the electric field intensity generated under the same phase sequence arrangement is the largest is obtained. In the literature[10], the three-dimensional model of transmission line considering the tower and insulator is established by finite element method, and the influence of the phase sequence of the conductor on the electric field distribution is analyzed. However, in the above literature, only the common tower type in the transmission line is studied, and the distribution of the electric field when the T-connected tower is used is not analyzed. Since the electric field distribution after the connection of the line T becomes more complicated, it is important to study the distribution of the electric field near the T-connected tower. In this paper, the 110kV double-circuit AC T-connected tower transmission line model is established by using the COMSOL software. The influence of different conductor phase sequence arrangement on the electric field distribution of the T-connected tower is analyzed, and the electric