Using IEEE 1588 v2 to Achieve the Synchronization of Sampled Values on the Substation Process Bus
Location / Country :
IEC 61850-3 24+4G-port Layer 2 Gigabit modular managed rackmount Ethernet switches
IEC 61850-3 Layer 2 IEEE 1588v2 PTP rackmount (PRP/HSR) Ethernet switches
Jiangsu province's rapid economic growth over the past few decades has made it one of the most energy-demanding provinces in China. With a 500 kV grid as its backbone, Jiangsu uses one of the largest electricity grids in China. 220 kV transmission plants cover all the urban and rural areas across the province. Key selection criteria in Jiangsu Provincial Electric Power Co.'s procurement process for electrical networking devices are advanced technology, high reliability, and excellent service.
In the Suzhou 500 kV substation, electronic current/voltage transformers (CT/VTs) and merging units convert analog signals to the IEC 61850-9-2 digital format. To deliver highly accurate synchronization of the sampled measurement values (SMV) on the process bus, Jiangsu devised a novel design based on the IEEE 1588 merging unit synchronization standard. In this project, Moxa provided IEC 61850 compliant Ethernet switches with IEEE 1588 v2 nanosecond-precise time synchronization solutions on the IEC61850 process bus.
• Nanosecond-level time synchronization of SMV streams
• Zero-packet-loss Ethernet switches for mission-critical GOOSE transmissions
• Next generation IEDs/protection relays with support for IEEE 1588 Ordinary Clock functionality
• Powerful processing ability for back-end host
• EMC level 4 standards for harsh environment
Highly accurate sampled measurement values (SMVs) are a crucial component of accurate system reliability analysis in the process bus environment. Without a well-synchronized SMV process bus stream, the system will be unable to achieve differential protection, synchrophasor measurements, or digital fault recording.
Moxa's IEC 61850 industrial Ethernet switches were used in this project to form a doubly redundant fiber network backbone with dual-tree topology for extra reliability. The electronic CTs/VTs and Merging Units are installed in pairs. On the process bus, the Moxa Ethernet switches used IEEE 1588 v2 transparent clock functionality for nanosecond-level accuracy synchronization of SMV streams while also eliminating the extra cabling requirements of 1PPS or IRIG-B to propagate highly accurate timing signals. In addition, rugged Moxa Ethernet switches provide zero packet loss for GOOSE transmissions.
The DA-710 computers are deployed as control units at the back-end host that help handle complicated computing tasks such as data analysis and device connections. These back-end computers leverage their powerful performance to reduce the workload of front-end tasks. With 4 PCI slots, the DA-710 are very flexible in accommodating future system expansions and reducing the cost of system deployment.
The IEEE 1588 v2 standard will only become more important for electric utilities in the future. By deploying the technology now, Jiangsu puts their network ahead of the curve and prevents costly system obsolescence. In the meantime, the technology pays dividends today by increasing the electric utility's efficiency and uptime through improved monitoring and troubleshooting.
• Precise IEEE 1588 v2 timing accuracy improves monitoring and troubleshooting capabilities.
• IEEE 1588 eliminates dedicated time synchs, which reduces the cost of wiring to sensors
• Using the latest IEEE 1588 v2 technology prevents technological obsolescence
• Powerful computers for processing various tasks
• EMC level 4 standards guarantee reliable operation in harsh environment