Combination of IEEE 1588 Time Synchronization and IEC 62439 PRP Communication Redundancy for Smart Grid Substation
Distributed Global Positioning System (GPS) receivers are widely used for accurate time synchronization in power industry,which helps prevent blackouts,improves fault location accuracy and provides enhanced differential feeder protection.However,concern about the reliability of GPS receivers has been raised since National Grid UK reported a significant number of protection relay mal-operations caused by incorrect timing data obtained from the GPS receivers.Meanwhile,vulnerabilities such as use of GPS jammers and natural interference (e.g.solar flares) also pose a potential threat to GPS timing reliability.Hence,utilities now require a timing system that is less dependent on the direct use of distributed GPS receivers.On the other hand,in order to reduce the cabling and enable the interoperability among devices from multiple vendors,utilities are looking to adopt the Ethernet based IEC 61850 protocol suites to complement or replace the conventional hardwired secondary protection and control (P&C) system.The IEEE 1588-2008 synchronization protocol can use the Ethernet to disseminate the time reference and is able to realize sub micro-second accuracy. With adequate implementation and engineering, a substation could use merely two or three 1588 time masters (with GPS receivers equipped) in conjunction with data network to achieve accurate synchronization instead of utilizing dozens of distributed GPS receivers. Ethernet has been chosen as the communication media for a number of IEC 61850 applications requiring bump-less communication redundancy whilst the existing technologies in a substation can only recover the communication within tens of milliseconds after a fault. Alternatively, the newly released IEC 62439-3 Parallel Redundancy Protocol (PRP) can achieve seamless redundancy communication by transmitting duplicate data packets simultaneously in the networks and this can satisfy the extremely high reliability requirement of the transmission substations. This paper described how a physical test-bed combining the IEEE 1588 time synchronization and IEC 62439-3 PRP seamless network redundancy was build up. After that, a set of tests focusing on the time offset and holdover capability were conducted to assess the performance of the IEEE 1588 clocks, when operating without and with the PRP redundancy. Refer to communication in a substation; various traffics would share the Ethernet with the IEEE 1588 message. Therefore, the performance of the mixed 1588 / PRP network was also evaluated under different network conditions. The experimental results showed that implementation of IEEE 1588 time synchronization over PRP network could provide an accurate and secure timing system for critical P&C applications in substations. Recommendations on future application of 1588 and PRP were also made so that utilities could have superb confidence when applying these two technologies in real substations.
Substation Ethernet Communication IEEE 1588 Time Synchronization IEC 62439 PRP Network Redundancy Laboratory Test-Bed Performance Test
Hao GUO Peter CROSSLEY Ray ZHANG
The University of Manchester,United Kingdom National Grid United Kingdom
国际会议
国际大电网会议组织保护与自动化专业委员会年度会议暨学术研讨会
南京
英文
1-7
2015-09-20（万方平台首次上网日期，不代表论文的发表时间）