Study On EHV And UHV AC Transmission Engineering Electromagnetic Environment

Nowadays, the development of ultra-high voltage and extra-high voltage grid is faster and faster, its reasons mainly lie in:Energy can be used more effectively; Reduces occupancy area, saves investment cost; Relieves energy pressure, makes the development of national economy better and faster. The purpose of this paper is to calculate electromagnetic field under the overhead transmission line and the induced stationary current through the human body who is in the electromagnetic field. The main research results of this paper are as follows:For electric field calculation, firstly, this thesis builds a calculation model of two-dimension electric field with charge simulation method(CSM), gives a concrete calculating example and analyzes the related characteristics of two-dimensional electric field. Secondly, it uses charge simulation method, combining catenary model to calculate three-dimension(3d) electric field, and compares the calculated value with the actual measured value to verify its accuracy. Compare with the two-dimensional model, the calculation results show that this method is more accurate to reflect the electric distribution. This thesis analyzes the influence to electric field distribution in different situations, such as:ground wire, distribution mode of transmission line, phase spacing, height of suspension point, tower shape, distribution of conductor, wind speed. It gives the fitting relationship curve of distance and maximum field strength, also the fitting relationship curve of the height of suspension point and the biggest electric intensity.For magnetic field calculation, firstly, this thesis builds a calculation model of two-dimension magnetic field with Biot-Savart law, gives a concrete calculating example and analyzes the related characteristics of two-dimensional magnetic field. Secondly, it uses Biot-Savart law, combining catenary model to calculate three-dimension(3d) electric field, and compares the calculated value with the actual measured value to verify its accuracy. Compare with the two-dimensional model the calculation results show that this method is more accurate to reflect the magnetic distribution. This thesis analyzes the influence to magnetic field distribution in different situations, such as:distribution mode of transmission line, phase spacing, height of suspension point, tower shape, distribution of conductor, wind speed.The theis Adopts equivalence column model, calculate the induced stationary current through human body caused by the electric field which is conducted by transmission line. This method has such advantages:simple calculation steps, small amount of calculation and facilitate the project operation.All the electromagnetic field calculations are realized by MATLAB software, all the calculation results are expressed in chart form, so the enhance the readability of this paper is enhanced.