Abstract
The magnetic field (MF) produced by the bus bars in the urban distribution substation can pollute the environment, and shielding measures should be taken. In the paper the model to calculate the power frequency magnetic field around an urban distribution substation is presented firstly, then the calculation on the magnetic field produced by the three-phase bus bars was carried out, and influence on the magnetic field distribution caused by different parameter was analyzed. The results indicate that to decrease the magnetic field in the upper floor, it's better to make the distance between the bus bars within 0.4 m, and the height of the bus bars within 0.1 m. Then the shielding measures to eliminate the magnetic field in the upper floor residential housing were investigated, and results indicate that the smaller size of the reinforced grid and the greater diameter of the reinforced bar, the better is the shielding effectiveness. For the shielding of the magnetic field in the up floors, the shielding effectiveness can reach 33.52 dB with an 8 mm thick shielding steel plate used in the floorboard. Considering the economic cost, the shielding grid made of 8# reinforced bars (net size: 0.10*0.10 m