750 kV高海拔交流输电线路无线电干扰测试数据分析

Analysis of Radio Interference Measurement Data for 750 kV AC Transmission Lines at High Altitude

为建设高海拔特高压交流输电线路,需要掌握高海拔输电线路的电晕特性以指导设计,针对官亭长期观测站的750 kV单回输电线路无线电干扰典型测试数据进行了分析,研究表明:好天气下的无线电干扰基本都在55 dB以下,满足控制限值要求,雾和霾天气测量结果一般和好天气的基本相当。获取了无线电干扰在线路停电前后和带电前后的测量结果,无线电干扰可作为判定线路带电与否的一个判定依据。线路重新带电后,无线电干扰较大,随着带电时间逐渐增加,导线表面积灰去除后,无线电干扰减小。获取了无线电干扰随降雨、降雪量的变化规律。无线电干扰频谱在0.15~20.00 MHz大体上有衰减趋势,在较低频率的0.15~1.00 MHz标准频谱与实测结果基本相当,频率增加后,标准频谱较实测结果偏大,给出了一种更为接近的拟合曲线。

In order to build ultra-high voltage AC transmission lines at high altitude,it is necessary to master the corona characteristics of transmission lines at high altitude to guide the transmission lines design.The typical radio interference data of the750 kV single circuit transmission lines measured at the Guan-ting long-term observation station were analyzed.The study results showed that the radio interference under fair weather was basically below 55 dB,which met the control limit requirements;the measurement results under fog and haze weathers generally had little difference from those under fair weather.The radio interference before and after line outage and line recharged was measured separately,and the radio interference could be used as the criterion to determine whether the transmission lines were powered or not.After the transmission lines were recharged,the radio interference was larger and increased gradually with the time,and decreased after removal of the dust on the conductor surface.The variation characteristics of the radio interference with rainfall and snowfall were obtained.The radio interference spectrum had a tendency of attenuation in the range between 0.15 MHz and 20.00 MHz.The standard spectrum in the lower frequency band between 0.15 MHz to1.00 MHz was basically consistent with the actual measurement results.With the increase of the frequency,the standard spectrum level was larger than the measurement results,and a closer fitting curve was given.