中低压电力线路载波幅频特性

CARRIER AMPLITUDE FREQUENCY PROPERTY OF MIDDLE AND LOW VOLTAGE TRANSMISSION LINE

文章根据电路理论建立了中低压电力线路载波幅频特性的物理和数学模型，通过计算机计算绘出了中低压电力线路载波幅频特性曲线，得出了中低压电力线路载波幅值随频率及距离变化的一般规律，找出了中低压电力线路载波的理想频段：３８０／２２０Ｖ线路上，当用户处无阻波器时，载波信号衰减很快，而且相邻两用户间的距离越短载波信号衰减越快；当相邻两用户间的距离为１０ｍ时，信号传送距离约２００ｍ，频段为０．１～１０ｋＨｚ；当用户处有阻波器时，载波信号衰减很小，在３０ｋｍ范围内可用频段为０．１～２００ｋＨｚ。１０ｋＶ线路上，较合适的频段为０．３～５００ｋＨｚ。

A physical and mathematical model of carrier amplitude frequency property of middle and low voltage transmission line is given in this paper. On the basis of calculation results the carrier amplitude frequency curve of middle and low voltage power transmission line is drawn, and a rule by which the carrier amplitude of middle and low voltage power transmission line varies as the change of frequency and distance is obtained. The authors point out that for 380/220V power transmission line without obstructor at the user's terminal the carrier signals attenuate quickly, and the shorter the distance between adjacent users is, the quicker the signal attenuates, when this distance is 10m, the transferring distance of signal is about 200m and the applicable frequency range is 0.1～10kHz; for the same line with obstructor at the user's terminal the attenuation of carrier signal is weak, when transferring distance is 30km, the applicable frequency range is 0.1～200kHz. For 10kV power transmission line the appropriate frequency range is 0.3～500kHz.