Innovative GPON Communication Framework for Reliable Differential Protection in Distribution Networks

This paper explores the deployment of a slicing-enabled gigabit passive optical network (GPON) architecture to address the stringent communication requirements of differential protection in power distribution networks. Differential protection, a critical fault detection method, relies on synchronized current measurements exchanged between remote terminals within sub-millisecond intervals. Conventional GPON systems, designed for best-effort data services, lack mechanisms to ensure deterministic delay, secure transmission, and service isolation, which are essential for time-critical protection applications. To overcome these limitations, the proposed architecture integrates fixed-bandwidth transmission containers (T-CONTs, Type 1), dedicated GEM ports, IEEE 1588v2 time synchronization, and hard slicing mechanisms to guarantee bounded latency, minimal jitter, and robust service isolation. Additionally, a dual-bus protection design enhances fault tolerance and network resilience by providing redundant optical paths. The system's performance was validated through field tests on a live optical ring interconnecting substations and distribution nodes. Experimental results demonstrated that the end-to-end communication delay remained within <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$201 \mu \mathrm{s}$</tex>, well below the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$300 \mu$</tex> s threshold required for differential protection, even under traffic congestion. These findings confirm the feasibility of applying slicing-enabled GPON networks as secure, scalable, and low-latency communication solutions for digital power grid protection applications.