Data communication through distribution networks for smart grid applications

In this study, a novel solution is introduced to deal with excessive signal attenuation in distribution transformers for power line communication in smart grids. The results presented were not achievable before proposing this solution because of the filtering action of transformer. The solution is based on exploiting a unique frequency resonance spotted in transformer windings at 490 kHz with an amplifying gain (~2 V/V) and a bandwidth about 40 kHz. It was successfully investigated to transmit a communication signal through 15 kVA distribution transformer. The 40 kHz bandwidth and the associated amplifying gain allowed fast and efficient transmission of data, which was not feasible before. The error of a coded binary phase shift keying signal propagating through a distribution transformer was measured in the laboratory. This simple and effective solution avoids costly hardware, such as bypassing circuits, and does not require sophisticated communication modulation schemes such as orthogonal frequency division multiplexing. A full model was developed for system simulations. The work evaluated factors that may influence the resonance frequency such as distribution cables and transformer ageing. All the simulated results were verified experimentally and met the expectations of the presented solution.