Tele and current differential protection over MPLS-TP (OTN Systems).pdf

Tele and current differential protection over MPLS-TP

1. OTN Systems KOTE Landsmøte 1

2. OTN Systems KOTE Landsmøte 2
Tele-and current differential
protection over MPLS-TP
Veerle Peeters (Business Development Manager)
KOTE Landsmøte–2017 -Bodø
Foto: Ernst Furuhatt/Visit Bodø

3. OTN Systems KOTE Landsmøte 3
Delivering the critical network element for industrial networks as part
of anend to end solution for Operational Telecom
Power
Utilities
Electric
Transport
Gas
&
Oil
Network
Equipment
Network
Management
Services
& Support

4. OTN Systems KOTE Landsmøte 4
Substation Communication
WAN
MPLS-TP
RTU
Function FunctionFunction
Protection
relais
Tonext substation
SubstationSwitch
C 37.94, G.703, E1…
Ethernet, E1, ...
Ethernet, Serial Comms, ...
SubstationAutomation SubstationProtection
SubstationAuxiliarySystems

5. OTN Systems KOTE Landsmøte 5
Recent CIGRE publication June 2016
•“MPLS-TPin the context of operational telecom seems to be
the appropriate technology when going to packet”
oMaintaining full control of the Network
oQuality of Service and deterministic behavior
oSize of network and type of traffic
oCapability versus complexity
oMigration from SDH

6. OTN Systems KOTE Landsmøte 6
Most sensitive application: current differential protection
•Current differential is a protection functionality
based on comparison of measured values
•Difference means that there is a fault existing
•Comparison of similar measurement is essential
•Variation of transmission time “looks” like a fault
current for the relay
oPerformance criteria are based on
•End-to-end delay variation
•Differential delay
oSensitivity depends on time accuracy of compared
values
oBigger jitter and differential delay can lead to
unwanted trip signals
Balance between DEPENDABILITY and RELIABILITY

7. OTN Systems KOTE Landsmøte 7
MPLS-
TP
Jitter Buffer
MPLS
-TP
Jitter Buffer
TX
RX
Internal Clock
Adaptive/Differential
TX
RX
Typicalsetup –Network view
Packetization
Clock recovery
Label swap
Label swap
Label swap
Label swap
Label swap
Label swap
Label swap
Label swap
Label swap
Label swap
Clock recovery
Packetization

8. OTN Systems KOTE Landsmøte 8
Jitterin end-to-end delay
•Jitter in end-to-end delay exists when packets are delayed in the network
Strict traffic engineering (TE) limits the issue and combined with de-jitter
buffer at both ends solves the issue. In MPLS-TPthis is part of the NMS.
When strict TE is applied adaptive clocking can be used as alternative to
differential clocking

9. OTN Systems KOTE Landsmøte 9
Differential Delay (1/2)
•Exists when the delay between A-B is different then the B-A. Is created when:
A B
Different paths for A-B
and B-A
Solved by MPLS-TP –including protection switching
Packetization/buffer A
is different then B
Solved by NMS of MPLS-TPwhen service is configured end-to-end

10. OTN Systems KOTE Landsmøte 10
Differential Delay (2/2)
•Exists when the delay between A-B is different then the B-A. Is build up when:
Delay in a each nodeIn control when network is strictly traffic engineered and
protection traffic is in high QoS –solved by TE of MPLS-TP
Different delay in the
de-packetization A/B
Buffer levels should be equalized ornetwork nodes must be
synchronized (Sync-E/IEEE1588v2)
A B

11. OTN Systems KOTE Landsmøte 11
Evaluatedbytheexperts
•The University of Strathclyde,
in Glasgow, UK, hosts the
Institute for Energy and
Environment,
oLargest power systems research
institute in Europe
o250 staff and PhD students
•The Technology and Innovation
Centre (TIC) within Strathclyde
provides a bespoke and
dynamic laboratory for testing
novel power systems research. Differential
Protection
Relay
Differential
Protection
Relay
C
37
.
94

1G 1G
XTRAN (200)
C
37
.
94

SDH SDHSTM-11G 1G

XTRAN (100) XTRAN (300)
10G

12. OTN Systems KOTE Landsmøte 12
SetupDifferential
Protection
Relay
Differential
Protection
Relay
C
37
.
94

1G 1G
XTRAN (200)
C
37
.
94

SDH SDHSTM-11G 1G

XTRAN (100) XTRAN (300)
10G

13. OTN Systems KOTE Landsmøte 13
Evaluation results
•MPLS-TP performed as expected and
industry values were respected under all
conditions, including different service
protection schemes.
•Different circuit emulation parameters
where evaluated. Delays could be as low
as 3ms for delay optimized setups.
End-to-end delay < 6ms
Differential delay< 400 µs

14. OTN Systems KOTE Landsmøte 14
Evaluation results
•Evaluated protection schemes
oMPLS-TP protected
oHitless switching
•Verification if symmetric delay is
maintained on secondary path when
single fiber is cut
Impact on delay and differential delay
was nihil. No false trips.

15. OTN Systems KOTE Landsmøte 15
Evaluation results
•Load testing
oBackground Ethernet traffic with/without
jumbo frames
oMultiple protection streams in parallel
Impact on delay and differential delay was
nihil when protection traffic was put in
highest queue and strickt priority was
used. No false trips occurred.

16. OTN Systems KOTE Landsmøte 16
Evaluation results
•Circuit emulation technologies like SAToP/CESoP and
adaptive/differential/internal clocking where
evaluated
oSAToP vs CESoP: SAToP offers lower delay but higher
bandwidth.
oAdaptive clocking requires more attention during network
design but simplifies the network compared to differential
clocking/internal clock who require synchronization of the
network.
•XTran specific:
oThe hitless switching function provides its value under
simulation of different network failures. Delays where
constant and independent of the network path.
oThe TXCare NMS predictions for delay where spot on.

17. OTN Systems KOTE Landsmøte 17
Evaluation results
AlstomP545: C37.94 –X.21 –E1
GE L90: C37.94
Siemens SIPROTEC 4 : X.21 -OLS
Siemens SIPROTEC 5 : X.21 –OLS –C37.94
Siemens SWT3000 : E1
SEL 411L : C37.94
SEL 2595 : C37.94

18. OTN Systems KOTE Landsmøte 18
Conclusion
•Current differential protection can be
easily transported via MPLS-TP
•The NMS with end-to-end configuration is
necessary
•A utility specific product offers advantages
to give the application more comfort
(hitless switching, buffer alignment,…)
•The Technical Innovation Center is an
ideal location for evaluating specific
setups in regards to protection

19. OTN Systems KOTE Landsmøte 19
MPLS-TPoffers new opportunity's.
Let’smake the change together!
Contact usand askforthewhitepaper.