The knowledge of the Power Line (PL) network impedance is relevant to improve the performance of the communication system and enable smart grid monitoring and diagnostics. This paper introduces a new method to estimate the PL grid impedance exploiting only voltage measurements and changes of the load at the receiver side of the Power Line Communication Modem (PLM). The proposed estimation technique is called Non Intrusive (NI) because does not require signals to be injected at the measurement port. But signals originated from a remote node are exploited for the impedance estimation. The exploitation of PLMs not only as communication devices but also to sense the Power Line Network (PLN) parameters, will promote new applications in the domain of PL diagnostics and allow better PL grid monitoring. The method was evaluated through simulations and real measurements. The proposed approach applies to both single and multi-conductor technologies at different frequency bands.
