摘要
针对因漏拆临时地线导致带地线合闸事故时有发生的问题,设计了一种临时地线检测装置,用于检测挂接在停电线路中间部位通过杆塔接地的临时地线。该装置充分利用了线路阻波器对工频感应信号呈现低阻抗、对200 kHz的高频正弦信号呈现高阻抗的特点,将200 kHz正弦信号加到停电线路上,根据从采样点采集到的200 kHz信号的电压幅值不同,判断线路中间位置是否挂接临时地线。同时,采用单片机对采集的信号进行数字滤波,并将固定时间段内采集的电压信号中幅值高于门槛值的次数作为判断线路是否有接地线的依据。并且工频感应电流经阻波器和线路两端的地线流入大地,确保了检测装置不被工频感应电压击穿。该装置在河北省某220 kV架空输电线路上进行了现场试验,结果证明该装置可以有效识别停电线路中部通过杆塔接地的临时地线,验证了该装置的有效性。
Leakage demolition of temporary ground wires often lead to accidents of closing circuit breaker with any ground wires on. For this, a detection device is designed, which is exclusive for the detection of temporary ground wires connected to the ground through towers. Traps present low impedance for frequency induction signal while they present high impedance for high frequency sinusoidal signal of 200 kHz. Add sinusoidal signal of 200 kHz to power outage line and it can decide whether there is any ground wires attached to the power line according to the amplitude of 200 kHz signal of the sampling point. The microeontroller completes digital filtering work of the acquisition signal and makes the number of amplitude above the threshold voltage signal determine whether there are any temporary ground wires connected to power lines. Inducted current will flow into the earth through the path of traps and ground wires at the both ends of power lines, which prevents the device from being damaged by inducted signals. The field test of the device has been taken with a 200 kV overhead transmission line in Hebei Province and the result provides that it can effectively identify ground wires grounded to the earth through intermediate portion of the tower, that is to say, the result verify the validity of the device.
出处
《内蒙古电力技术》
2013年第2期67-71,共5页
Inner Mongolia Electric Power
关键词
输电线路检修
临时地线检测装置
阻波器
高频信号
数字滤波
transmission line maintenance
detection device for temporary ground wires
traps
high-frequency signal
digital filtering
