Measurement and research of channel transmission properties on 10 kV medium voltage power lines. Part 1: General properties

In two typical 10 kV power networks, the frequency response is measured on loop wires and the path loss is obtained by employing the transmitting/receiving mode. Based on the empirical data, transmission properties of the channel are investigated using the transmission line model. The frequency range is over 40 kHz-1.5 MHz. Results show that the power attenuation through the channel is about 10-20 dB/km when the channel does not have a branch. The channel is time dispersed. In the frequency domain, the amplitude response is frequency selective while the phase response is linear. In the time domain, the impulse response shows a delay spread. The rms delay spread and the coherence bandwidth are in correlation with the network structure, and corresponding values are on the order of ten μs and ten kilohertz. The narrow fading of the channel follows Nakagami-m distribution. The channel is varying weakly with respect to time. When the data rate is up to Kbit/s, the channel can be regarded as time invariant.