On the time invariance of PLC channels in complex power networks

In this paper new time invariant properties of PLC (Power Line Communication) channels are pointed out. First, we have obtained an equivalent lumped circuit that represents the transmission line characteristic of a power cable starting from the analytical solution of the telegrapher´s equations. Then, the Y matrix has been employed to compute the transfer function between power network ports, taking into account load variations. The effect of a high number of branches in the network on transfer function diagrams is investigated. Both simulation and measurement show that in a complex power network (with several parallel connected branches) the time varying phenomenon of the transfer function, caused by the load on-off switching, is strongly reduced. A demonstration is here provided to support these results.