On the Utilization of System-on-Chip Platforms to Achieve Nanosecond Synchronization Accuracies in Substation Automation Systems

A synchronized common sense of time is a key factor for many smart grid applications, such as the sample value process bus operation. The precision time protocol (PTP), as defined in IEEE 1588-2008 standard, is highly recommended for substation communication networks, because it enables synchronization accuracies in the nanoseconds range through conventional Ethernet-based networks. This paper explores the implementation of PTP functionalities on new Xilinx Zynq-7000 all programmable system-on-chip (SoC) device. Different PTP master and slave implementations have been analyzed taking benefit from the flexibility of the SoC all programmable devices. The explored features go from simple only-software versions aided by PTP support of Gigabit Media Access Controllers (GMACs) embedded in the processor section to high-accuracy solutions that include custom PTP hardware in the logic section of the device. For each configuration approach, two different experimental setups based on two Zynq commercial low-cost boards has been built, and the protocol performance has been evaluated by measuring time offset between the pulse per second output signals of the master and the synchronized slave. The results obtained from this analysis show excellent accuracy results, with time offsets in the range of 40 ns and standard deviations of less than 10 ns.