The Analysis Of Electromagnetic Environment For 1000kV UHV Transmission Line

There are the urgent need of electricity supply for national economy rapid development and space distribution of energy resources and load characteristics in our country, which determines the necessity of building the long-distance, large-capacity, and high voltage transmission system. With the rapid development of our national economy and the growing public environmental awareness, the electromagnetic environment problem of the special high-voltage transmission line has received increasing attention.1000 KV UHV transmission line electromagnetic environment parameters consist of frequency electric field, power frequency magnetic field, radio interference and audible noise. The radio interference and audible nose mainly caused by the corona discharge line. This paper takes the 1000KV UHV transmission line for study and has a simulation research of the frequency electric field, power frequency magnetic field and corona discharge. The research work has shown the following:1. The power frequency electric field, the author compares the main methods of the current frequency electromagnetic field analysis in this paper, and establishes 1000KV UHV AC transmission line model of two-dimensional electric field. The authors analyzes the general principle of the line bottom frequency electric field intensity distribution and the change by calculating, and focuses on the principle of the factors of the tower and the phase conductor arrangement, the distance between phase conductors, split wire structure, grounding wire (overhead ground wire), wire-to-ground distance of the transmission line bottom frequency electric field and the line corridor.2. The frequency magnetic field, the author establishes the 1000KV UHV AC transmission line model of two-dimensional magnetic field and researches the influencing principle of the factors on the transmission line bottom frequency magnetic field, such as the line phase current, tower and the phase conductor arrangement, the distance between phase conductors, split wire structure, and wire-to-ground distance by calculation of the general principle of the line bottom frequency magnetic field intensity distribution and the change3. In the corona discharge, the author establishes the 1000 kV UHV AC transmission line corona discharge model and analyzes the wire surface field intensity's influence on the line corona discharge by simulation calculation, and specially focuses on the UHV transmission lines effects caused by corona discharge of radio interference, audible noise and corona losses.4. The author compares the simulation results with the current domestic and foreign special electromagnetic environment of special high pressure and ultra high pressure limits, and found that 1000 kV UHV AC transmission line electromagnetic environment parameters are within limits, if the proper measures can be adopted, the UHV electromagnetic environment may be achieved.5. According to the results of the calculation and analysis, this article suggests: the design and construction of our 1000kV UHV AC transmission lines should adopt triangular layout as more as possible, which features multi-split wire, large cross section wires, raising the height of line-to-ground measures to reduce the electromagnetic circuit environmental parameters. In addition, in the design of alignments, the relatively high rain areas should be avoided to reduce the line audible noise and radio interference levels and reduce corona losses.