White Rabbit HSR: A Seamless Subnanosecond Redundant Timing System With Low-Latency Data Capabilities for the Smart Grid

New smart grid and industrial-Internet-of-things (IIoT) directions require accurate synchronization features to capture, trigger, and manage events in industrial networks with the best possible precision and accuracy. The implementation of redundancy features for time and data distribution to increase fault tolerance, together with an enhancement of the availability of the network services such as generic object-oriented substation events, become mandatory due to their critical nature. For these reasons, the authors of this paper presented a new challenging approach covering the industrial standards requirements regarding timing and availability through the development of mechanisms that make possible the avoidance of single point of failure in ring topologies. This approach uses the White Rabbit (WR) as the main timing distribution technology, able to synchronize devices below 1 ns. Moreover, the development of a mechanism able to change from a primary to a backup time reference in approximately zero time with an observed maximum phase shift of 170 ps implies an important qualitative leap with respect to IIoT and the smart grid (e.g., phasor measurement units). This paper addresses the development and results of the high-availability seamless redundancy protocol for the WR technology to conform a leading-edge deterministic and reliable ultraaccurate timing system with high-availability data features for industrial facilities in accordance with IEC 61850 and IEC 62439-3.