Analysis of Correlation between Phase Sequence Arrangement and Power Frequency Electric Field in Extreme High Voltage Transmission Corridors

Abstract

Extreme high voltage transmission line has a great influence on electromagnetic environment especially when two Extreme High Voltage transmission lines share one transmission corridor. In order to study the influence of phase sequence arrangement on power frequency electric field at ground surface, electromagnetic simulation is carried out in this paper. First, phase sequence arrangement is studied in this paper. There are 72 types of phase sequence arrangements in total and 24 types of different phase sequence arrangements remain after excluding the repeated ones. Based on the parameters collected from the engineering construction sites of 1000kV AC and ±800kV DC transmission line in Jiangsu province, a two-dimensional model is established in Ansoft. By dividing a fundamental frequency cycle into 24 parts, the electric field at ground surface is calculated at each time piont to find out the phase sequence arrangement under which the maximum electric field is the least. The result indicates that the power frequency electric field at ground surface has a close relationship with phase sequence arrangement of AC transmission line. When two AC transmission lines have same phase sequence, the electric field at ground surface is the largest. When two AC transmission lines have reverse phase sequence, the electric field at ground surface is the least. And when two AC transmission lines have different phase sequence, the electric field at ground surface is medium which is less than the same phase sequence and larger than the reverse phase sequence.