| In recent years,with the rapid development of the offshore wind,Marine transmission engineering also has the trend to extra-high voltage.Of course,the voltage and rated operating current of submarine cable have increased,the influence of the Marine ecological environment caused by submarine cable electromagnetic environment has become increasingly obvious.The world and the marine conservation organizations are very concerned about the power frequency electromagnetic field problems of submarine cable.So,the power frequency electromagnetic field problems becomes the key factors which restrict the development of the Marine power transmission and the offshore wind.Research on the electromagnetic environment of submarine cable has important implications for the construction of marine transmission project.This paper is based on a 35 kV three-core photoelectric composite cable submarine which is 10 km long.Analytical calculation,COMSOL Multiphysics finite element simulation and experiment measurement are used to analyze the power frequency electromagnetic field of submarine cable.In order to study the effects of power frequency electromagnetic field to Marine life,in this paper,behavior influence on sea biological surrounding the submarine cable has carried on the experimental study,the result illustrates the submarine cable power frequency electromagnetic field has certain influence on the Marine ecological environment.This paper mainly carries out the following research:(1)According to the principle of electrostatic shielding,power frequency electric field out of cable is zero.Based on the image method,this paper calculates the power frequency magnetic induction intensity at the top of the cable,and the influence factors of the magnetic field above the submarine cable is analyzed.(2)Using COMSOL Multiphysics finite element simulation,both internal and external electromagnetic field are emulated.The induced voltage,electric field intensity,the induced current,loss and magnetic induction intensity of submarine cable are carried on the thorough analysis.The analysis draws the magnitude and influence factors of external electromagnetic fields of the submarine.The influence of armour's material properties on the external magnetic field of submarine cables is simulated in detail to determine the influence of material properties on the internal and external magnetic field of submarine cables.Combined with analytical calculation and finite element simulation,the attenuation scheme of the submarine's power frequency electromagnetic field is proposed.(3)The simulation experiment of the submarine's electromagnetic environment is designed,and the plans for the installation,operation and measurement are given.All plans are implemented.The temperature change of the submarine cable in different positions is measured.The external power frequency electric field and the power frequency magnetic field value are measured.The measured value is compared with the calculated simulation value to obtain the radiation value of the relevant electromagnetic field.In this paper,the scheme of the attenuated electromagnetic field is measured and analyzed.(4)Combined with the relevant knowledge of marine ecology,experiments were carried out on the behavior of clams,scallops and Anguilla rostrate under the electromagnetic radiation of the submarine cable.According to the experimental phenomena of marine biological experiment,the radiation limit value of the submarine cable's power magnetic field is obtained by analyzing the radiation limit of the existing frequency electromagnetic field. |
PDF Full Text Request