Design and Analysis of Reliable Current Differential Protection Through Improved Power-Line Communication

Current differential protection (CDP) typically requires a reliable communications to implement the correct actions. Power-line communication (PLC) thanks to its natural advantage becomes the most preferred communication medium for the CDP service; however, it always undergoes to the deep multipath fading and the strong additive noises, which impede its deployment in the CDP. In this paper, we delicate to the performance improvement of CDP service by designing a reliable and robust PLC signal in the PLC transceiver. Firstly, a quadrature amplitude modulation (QAM) based OFDM signal employing frequency-hopping (FH) technique is proposed into the classic PLC, which can boost the capability of suppressing the noise and fading in PLC channel. On the basis of the multipath fading following Manfred-Klaus model, and additive noises (background noise and impulsive noise) following Bernoulli-Gaussian model, respectively, the impact of the proposed FH/OFDM PLC signal on the protection action performance is studied via the step-by-step analysis. Finally, based on the signal derivation, the mal-operation rate and refusal operation rate of CDP are evaluated by extensive simulations. The analysis and simulations reveal that the proposed CDP system can attain the superior correct actions (e.g., lower mal-operation rate and refusal operation rate), which are benefited from the reliability and robustness of the proposed FH/OFDM PLC signal, compared to the previous CDP employing classic OFDM PLC scheme.