750kV兰州东官亭输变电工程工频电磁场测量

Measurement on the Electromagnetic Environment of 750kV Lanzhou-Guanting Power Transmission Project

为了解750kV变电站和线路的电磁环境参数,测量了我国已运行电压等级最高的第一个输变电工程-750kV兰州东官亭输变电工程的工频电、磁场,测得线路在跨越农田时地面1.5m处的最大场强为5.35kV/m;比对了线路工频电场测量值与计算值,两者吻合较好;在跨越山坡处线下最大场强11kV/m,由于此时斜坡影响计算值略小于实测值,兰州东变电站内750kV区域的场强在1.6～7.9kV/m范围内,磁感应强度的垂直分量最大值为1.1μT,水平分量最大值为1μT。实测表明,该电磁环境参数满足750kV示范工程主要电磁环境控制指标。

Compared with the 500kV transmission line, the 750kV power transmission line has some characteristics as follows： high voltage, large cross section, high tower and wide corridor. The problem of electromagnetic circumstance of 750kV is more serious than that of the 500kV transmission line. Thus, the electromagnetic circumstance should be measured and studied. This paper measured the electro-magnetic environment of 750kV Lanzhou Guanting power transmission project, whose voltage level is the highest inland. The maximal ground electric field measured under 750kV lines spanning over farmland is 5.35kV/m. Furthermore, the measured data and calculation value were compared, indicating a perfect accordance. The maximal ground electric field under 750kV lines is 11kV/m when lines are over hillside. At the same time, the electromagnetic circumstance of 750kV substation is different from the 500kV substation, so we have a measurement on the ground of the substation. The ground electric field strength is 1.60～7.90kV/m , and the magnetic induction intensity is about 1.4μT in 750kV Lanzhou substation. The audible noise of 750kV line is very low comparing with background noise. Results indicate that the measured environment parameters meet the requirements of main electro-magnetic control objectives of 750kV demonstration project.