Study on Radio Interference of AC UHV Double Circuit Transmission Lines on the Same Tower

AC UHV power transmission has become the strategy and program of building strong electric power grids in our country for it can transmit high voltage and long way and realize electric resource optimizing collocation in a wide range. Compared with single-line, same tower double-line has the advantage of reducing the line corridor and saving the land resource, optimizes the arrange way of conductor at the same time ,and reduces electric and magnetic field on the ground, so it could become a important way of developing AC UHV power transmission in our country. The problem of electro-magnetic environment is the key technique problem in building UHV power transmission. Radio interference as the characteristic of conductor corona will directly influence the choice and arrange way of the line conductor and the settlement of the height the conductor to the earth and the tower type. This study carried out the calculation and analysis on the radio interference of AC same tower double UHV power transmission and proposed the line parameter satisfied with the request of radio interference. We can draw the conclusion as follows: 1)1000kV double circuit on one tower, the two kind of tower, the cross-section is larger than 8×LGJ-630, mentioned above. The value of radio interference below 55dB(μV/m). To satisfy the limit of 58dBμV/m, the height of conductor should be increase in a large range when it is arranged in inverse array of phase. 2) The same array of phase can reduce the value of radio interference, but will increase the electric intensity on the ground. As a result, when we choose the array of the conductor, we should consider the two factors. 3) The tower 1 is recommended as a result of considering of reducing the radio interference.