Time Synchronization (IEEE 1588) and Seamless Communication Redundancy (IEC 62439-3) Techniques for Smart Grid Substations

Communication is a key factor to the success of the future Smart Grid. Among various technologies, Ethernet is a predominant one for Local Area Network (LAN) communication due to its low cost and high speed and Power Substations will see increasing use of Ethernet in the protection & control sector. The Ethernet based IEEE 15882008 time synchronization protocol can realize sub-micro second accuracy and can be regarded as a good alternative to the conventional synchronization method based on distributed GPS receivers. Meanwhile, as the Ethernet will become the carrier of protection and control information, it is necessary to ensure fast or even zero recovery time when a communication failure occurs, which can be satisfied by IEC 62439-3 Parallel Redundancy Protocol (PRP) and High-Available Seamless Ring (HSR) protocol. This paper describes how IEEE 1588 and IEC 62439-3 PRP protocols, based on opposite network path knowledge, can be combined to achieve accurate time synchronization and analyzes the simulation results to give recommendations on future applications of these two protocols.