Impedance measurement of electrical equipment loads on the power line network

摘要

The exact knowledge of the equipment load impedance's on the power line is an important factor to design efficient PLC communication systems. The PLC channel is highly influenced by the connected of unmatched and time variant equipment loads to the power grid. The characterization of the PLC propagation channel is mainly dependent on the load impedance's characteristic. In this paper, we have performed a set of measurement on representative equipment that can be exist in a house, office and laboratory. The measurement procedure is based on access impedance measurement system presented in [1]. The measurement results has enabled the analysis of the impedance behavior in time and frequency domain within the frequency range between 30 and 500 kHz that is used by narrowband PLC systems. We have found that the impedance behavior of each equipment varies on the power grid, some equipment have time variant impedance and others have time invariant impedance. This is because of the switched power supply and the EMC filter design which change their behavior significantly on the power network. Furthermore, we have evaluated and validated the measured load impedance's in respect to time and frequency. This evaluation will allow the prediction and the classification of the connected equipment loads to the power grid.