Evaluation of butterworth coupling arrangement and line trap circuit for PLC integrated power system

Coupling Circuits (CCs) and Line Traps (LTs) are the two most important elements of PLC-integrated power system networks. CCs are used for selectively injecting PLC signals into the network, whereas the LT is used to restrict the PLC signal from entering into areas of the network where such signals may damage equipment. In this paper, a Butterworth filter based CC and a T-type LT circuit have been modelled, simulated and evaluated. The objective was to design power systems complaint coupling and line trap circuits to operate within the CENELEC frequency band. The key finding is that sufficient performance can be achieved in terms of the insertion loss profile of the CC and LT when such circuits are designed using commercially available off-the-shelf components. For the designed CC, the insertion loss was measured as -3 dB in the 55 kHz to 100 kHz range. For the LT circuit, the insertion loss was measured as more than -53 dB. This ensures low attenuation of the PLC signal by the CC, and high attenuation by the LT.