Applying PTP-to-SNTP time-gateway to IEC61850 systems

The paper describes the application of an improved Time Gateway for simplifying the integration of old IEC 61850 devices in new IEC 61850 Substation Automation System with IEEE 1588 PTP. Old devices typically retrieve time information with the well-known SNTP protocol which uses very different time representations and synchronization strategies with respect to PTP. Hence, the paper uses a transparent, full-software, Time Gateway for interfacing SNTP devices with a PTP synchronization domain, demonstrating its applicability by means of a prototype based on an FPGA. Experimental results show the Time Gateway improves the overall performance with respect to an SNTP-only system. Moreover, the experiments demonstrate that the synchronization accuracy is limited by the SNTP.