International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The efficient distribution of telemetry data via standard Ethernet networks has become an increasingly important part of telemetry system designs. While there are several methods and architectures to choose from, a solution based on IP multicast transmission provides for a fast and efficient method of distributing data from a single source to multiple clients. This data distribution method allows for increased scalability as data servers are no longer required to service individual client connections, and network bandwidth is minimized with multiple network clients being simultaneously serviced via a single data transmission.

Protection and Control (P&C) devices requiring accurate timing within a power transmission substation are commonly synchronized by distributed Global Positioning System (GPS) receivers. However, utilities now request a timing system that is less dependent on the direct use of distributed GPS receivers, because of the reliability issue of GPS receivers. In addition, to reduce device-to-device cabling and enable interoperability among devices from multiple vendors, utilities are looking to adopt the Ethernet based IEC 61850 protocol suites to complement or replace a conventional hardwired secondary P&C system. The IEEE 1588-2008 synchronization protocol is a network based time synchronization technique which can co-exist with the IEC 61850 applications and deliver sub-microsecond timing accuracy. A number of IEC 61850 applications require seamless communication redundancy, whilst existing technologies used in a substation only recover communications tens of milliseconds after a communication failure. Alternatively, the newly released IEC 62439-3 Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR) can achieve seamless redundancy by transmitting duplicate data packets simultaneously in various networks and this can satisfy the extremely high reliability requirements of transmission substations. Considering the benefits, a unified network integrating IEEE 1588 and IEC 62439 PRP/HSR can be foreseen in future substations, but utilities need confidence in these technologies before real deployment. Hence, it is necessary to conduct comprehensive tests on such a timing system so that better insight into the performance and limitation can be obtained. This thesis first investigates the feasibility to integrate IEEE 1588 and IEC 62439 PRP into a single Ethernet network using a simulation tool and subsequently presents how the hardware testbed is established. Meanwhile, although GPS receivers are commonly used for time synchronization in the power industry, their performance might not be fully investigated before deployment. Hence, this thesis also proposes a procedure to assess the performance in terms of long term stability and transient behaviour of a timing system merely based on GPS receivers and one based on a mixture of GPS receivers and IEEE 1588 devices. Test results indicate whichever system is used, careful design of equipment, proper installation and appropriate engineering are required to satisfy the stringent accuracy requirements for critical automation applications in power system.