A Line Impedance Calculator based on a G3 PLC modem platform

Power line communication is one of the most today used technologies, for both automatic meter reading and many other smart grid applications. In this framework, a characterization of electrical network in PLC frequency range is needed in terms of impedance measurement and received signal level. This can allow choosing the most suitable and less noisy frequency ranges for PLC transmission. Usually, these characterization measurements are performed with dedicated instrumentation and in the absence of mains voltage. This paper wants to propose an alternative solution, which allows these kinds of measurement to be performed using electronic boards currently used as on-field applications such as smart meters. To this aim, an innovative measurement tool is proposed, which does not need a specific characterization signal to be injected, because it uses the preamble of a generic PLC transmission. Moreover, the impedance calculation is performed using a FFT analysis, which does not require high computational capabilities. These features allowed the proposed tool to be implemented using a G3-PLC transceiver, embedded in many commercial smart meters, and low-cost additional hardware. The paper shows how the proposed system correctly measures the PLC impedance on CENELEC A, B and FCC frequency ranges.