iec 61850 process bus
TRANSCRIPT
-
8/10/2019 IEC 61850 Process Bus
1/53
IEC 61850 Process Bus
-
8/10/2019 IEC 61850 Process Bus
2/53
Scope
IEDs for Process Bus Page 26
-
8/10/2019 IEC 61850 Process Bus
3/53
Digital Substations In Context
On-Line Stability
Smart Dispatch
Management of Renewables
Demand Response
Management
On-Line Asset Management
Extended IEC 61850 Interfaces
Advanced Sbstation User Interface
1Gbit/s Ethernet
Cyber & Physical Security
Wide Area Protection & Control
Substation State Estimation
Digital NCIT & Substation
Equipments
VSC Grid Connections
STATCOM for Wind
Static Var Compensators
Energy Storage
Smart Control rooms Digital SubstationsSmart Power
electronics
Smart Transmission Grids
-
8/10/2019 IEC 61850 Process Bus
4/53
Generic Digital SS Architecture
Proxy
Multiple Ethernet
IEC61850.8-1
Station Bus
C37.118 Phasor Data
Grid Control
Rooms
AMU
Primary Eqpt with
embedded sensors
for Condition Monitoring
Prot. Px40
DRUs
Switches
WAN
CMU
SCS HMI
Multiple Ethernet
IEC61850.9-2 &
IEC61850.8-1
Process Bus
Digital SS ComponentsIntegrated Substation Automation System with
1. Substation Control System (SCS)
2. Condition Monitoring System (CMS)3. Smart Grid Applications (SG APPS Cyber,
Intrusion,
Wide Area Management)
4. Substation Phasor Data Concentrator
Several IEDs
1. Protection / Measurement with 9-2 interface
2. Bay Controller Unit (BCU)
3. Condition Monitoring Unit (CMU)
4. Switches & Telecom
5. Proxy Server
6. Merging Units7. Wide Area Control Unit
8. Power Quality /Disturbance Record Unit
(DRU)
9. Energy Meters
DMU
SG APPSCMS PDC
WACU
BCU
Other
substations
sPDC
SG APPS
APPS 2012 Stafford UK
-
8/10/2019 IEC 61850 Process Bus
5/53
Scope
IEDs for Process Bus Page 26
-
8/10/2019 IEC 61850 Process Bus
6/53
IEC 61850 Process Bus
Process Bus Elements Ethernet Network, 100 Mb/s
IEC 61850-9-2 LE for Sampled Values SV
Current measurement (CT)
Voltage measurement (VT)
IEC 61850-8-1 GOOSE Service Status position of Circuit Breaker / Switches (CB)
Trip signals from protections to CBs (Trip)
Commands from Control Systems (Open/Close)
Others (monitoring status reports, health, settings)
Time synchronisation
Microsec accuracy required
-
8/10/2019 IEC 61850 Process Bus
7/53
IEC 61850 Process Bus
61850-9-261850-9-2
61850-8-1
61850-8-1
Bay Level
Protection Control
Station LevelFunction A Function B
HV Equipment
Bay Level
Protection Control
HV Equipment
33
11
33
1166 66
99
44 55 44 55
88
77 Technical ServicesLogical View Of SA
-
8/10/2019 IEC 61850 Process Bus
8/53
IEC 61850 -9-2 Overview
Sampled Value Transmission
Unidirectional link (MU to IED)
Physical layer : Optic fibre (copper optional)
Data Link layer : Ethernet 100 Mbit/s
Application Layer : IEC 61850-9-2 Light Edition guideline to aid
implementation and interoperability
Sampling rate : 80 or 256 samples per cycle
Neutral current and/or voltage may be measured, or derived
Sampled values are multicast on the LAN
Defines Logical Device MU
Synchronising of sampling
-
8/10/2019 IEC 61850 Process Bus
9/53
IEC 61850 -9-2 Overview
4V; 4I
4V; 4I
IEC 61850-9-2LE Sampled Values
Each SV message has 4 voltages, 4 currents
Primary values, quality info
Current : 1mA to 2.14 MA, Voltage : 10mV to 21.4 MV
MU-L1
MU-L2
Protection
Bay 1Protection
Bay 2
(I1a, I1b, I1c, I1n, V1a, V1b, V1c,
V1n)
(I2a, I2b, I2c, I2n, V2a, V2b, V2c,
V2n)
-
8/10/2019 IEC 61850 Process Bus
10/53
APPS 2012 Stafford UK
IEC 61850 -9-2 Overview
SV frames are multicast
MAC Address range: 01-0C-CD-04-00-00 to 01-0C-CD-04-1F-FF
input on Merging Units Note the frame overhead : 24 bytes of raw data (per 3-phase
voltage and current) in about 125 byte Ethernet frame
Iax1000
32bitInt
IaQuality
32bits
Ibx1000
32bitInt
IbQuality
32bits
Icx1000
32bitInt
IcQuality
32bits
Inx1000
32bitInt
InQuality
32bits
Vax1000
32
bit
Int
VaQuality
32
bits
Vbx1000
32
bit
Int
VbQuality
32
bits
Vcx1000
32
bit
Int
VcQuality
32
bits
Vnx1000
32
bit
Int
VnQuality
32
bits
-9-2LE Sampled Value Frame
-
8/10/2019 IEC 61850 Process Bus
11/53
IEC 61850 Process Bus
Merging Unit Typical Naming
AMU : Analogue Merging Unit Interface with conventional instrument transformers
DMU : Digital Merging Unit
Interface with CB / isolators / earth switches
CMU : Condition Monitoring Merging Unit
DMU with condition monitoring features
NMU : Numerical Merging Unit
Interface with digital instrument transformers
-
8/10/2019 IEC 61850 Process Bus
12/53
CB
Status &
Trips
IEC 61850 Process Bus
Conventional Bay -typical Main 1, Main 2, BCU
Individual CT cores per IED
Independent tripping paths forMain 1 and Main 2 typically
APPS 2012 Stafford UK
-
8/10/2019 IEC 61850 Process Bus
13/53
IEC 61850 Process Bus
DMU#1
-8-1PRP
AMU#1
-9-2LE
DMU#2
-8-1PRP
AMU#2
-9-2LE
AMU#3
-9-2LE
Main1
P546
-9-2LE
-8-1PRP
Main2
P446
-9-2LE
-8-1PRP
BCU
C264
-9-2LE
-8-1PRP
Process Bus
(conceptual)
Digital Bay - Typical Main 1, Main 2, BCU
AMU, DMU
Ethernet links andswitches
Time synch eqpt
APPS 2012 Stafford UK
-
8/10/2019 IEC 61850 Process Bus
14/53
APPS 2012 Stafford UK
IEC 61850 -9-2 Overview
Sampling Synchronisation Why ?
Protection functions/algorithms require all input quantities to be
supplied in real time
Relay inputs may be from multiple MUs
o Substation layout
o Customer specifications
Eg: Distance Protection (Voltage & Current)
Both voltage & current supplied by one MU; synchronisation provided by
the MUVoltage from MU1 and Current from MU2; synchronisation by common
time reference input to MU
-
8/10/2019 IEC 61850 Process Bus
15/53
APPS 2012 Stafford UK
AMU #2
-9-2LE
V 0
I 36
V 18
I 81
1 ms delay
2.5 ms delay
IEC 61850 -9-2 Overview
SV frames from different MU may have uneven delays
Relay measurements will be incorrect unless the SV frames are timealigned
SV frames from different MU may have uneven delays
Relay measurements will be incorrect unless the SV frames are timealigned
-
8/10/2019 IEC 61850 Process Bus
16/53
IEC 61850 -9-2 Overview
Sampling Synchronisation - Techniques
1 PPS input on Merging Units
Merging Units with capability for IEEE 1588 synchronisation
Sampled Value frames carry synchronisation info
Time tags (count) relative to the start of the sec
Identifier for sync source Global, Local or No Sync
Indicates if the SV
frame is synchronised
Sample Count0 3999 at 50 Hz
0 4799 at 60 Hz
Counter resets every sec when a
time sync signal is received
-
8/10/2019 IEC 61850 Process Bus
17/53
Sampled Values Alignment in Relays
IEC 61850 -9-2 Overview
Time alignment of SV frames is necessary, and ensures correct
operation of protection functions dependent on multiple MUs The number of MUs may change depending on site
requirements and customer preferences
Delays arise from
Merging Units, due to their processing
Network, depending on its configuration and switches
Delays have a direct impact on the operating time of the scheme
Time tags (count) relative to the start of the sec
Identifier for sync source Global, Local or No Sync
APPS 2012 Stafford UK
-
8/10/2019 IEC 61850 Process Bus
18/53
Sampled Values Alignment in Relays
IEC 61850 -9-2 Overview
Case 1: Relay with
1 MU
Case 2: Relay with
2 MU
Case 3: Relay with
2 MU
MU Delay: Relay setting,
indicates worst case relative
delay expected in receiving
SV from all MUs linked to
the relay
In this case, no delaybetween SV frames from
MU#1 and MU#2
In this case, there is a 1msdelay between SV frames
from MU#1 and MU#2
APPS 2012 Stafford UK
-
8/10/2019 IEC 61850 Process Bus
19/53
IEC 61850 -9-2 Overview
Sampling Synchronisation Accuracy
Time source accuracy +/- 1s SamplingacrossmultipleMUs synchronisedtowithin+/ 4s
MUshouldbecapableofcompensatingnetworkdelays>2s
MiCOM P594
-
8/10/2019 IEC 61850 Process Bus
20/53
IEC 61850 -9-2 Overview
Sampling Synchronisation 1 PPS
1PPS signal, transmitted by fibre as medium
Rise and fall time < 20ns
Clock source : Typically based on GPS
Global 1PPS: GPS is alive, pulse width between 5s and 500 ms
Local 1PPS : Pulse width between 0.9s and 1.1s
No Sync : Merging Unit hold-over mode
1PPS
-9-2LE SAV
P594 Merging Unit
-
8/10/2019 IEC 61850 Process Bus
21/53
IEC 61850-9-2 Overview
Sampling Synchronisation IEEE 1588
It is a high precision time synchronization (
-
8/10/2019 IEC 61850 Process Bus
22/53
IEC 61850-9-2 Overview
How does IEEE 1588 compare with NTP (SNTP) ?
Master/slave arrangement, against peer-peer in NTP
Target of microsec accuracy vs millisec in NTP
NTP is intended for internet, IEEE 1588 for LAN with few subnets
Smaller network message & computation requirement
Both include latency correction NTP has to be configured, whereas IEEE1588 is self-organising
Master Slave / Master Slave / Master
-
8/10/2019 IEC 61850 Process Bus
23/53
IEC 61850-9-2 Overview
t1 t4
t2 t3
Sync message from Master
Follow Up message from Master with value of t1
Delay Request message from Slave
Delay Response from Master with value of t4
Master
Slave
t1, t2, t3, t4
known to Slave
IEEE 1588 - Time correction on the network
-
8/10/2019 IEC 61850 Process Bus
24/53
IEC 61850 -9-2 Overview
MS = t2 t1 = Clock offset + MS delay
SM = t4 t3 = Clock offset + SM delay
Clock offset = {( MS SM) (MS delay SM delay )}/2
MS delay + SM delay = { MS + SM }
ASSUME: MS delay = SM delay = Path delay
Then:
Clock offset = { MS SM}/2
Path delay= { MS + SM}/2
M : Master ClockS : Slave Clock
IEEE 1588 - Time correction on the network
-
8/10/2019 IEC 61850 Process Bus
25/53
Scope
-
8/10/2019 IEC 61850 Process Bus
26/53
IEDs for Process Bus ApplicationsRelay - Example
MiCOM P444 Distance Relay with SV Interface
Have the 9-2 board instead of the Analogue module The 9-2 module resamples the SV received
Analogue module output on the internal bus at relay sampling rate No change in protection algorithms
Selection of SV inputs
/ Logical Nodes
-
8/10/2019 IEC 61850 Process Bus
27/53
IEDs for Process Bus ApplicationsRelay - Example
Px4x Process Bus Interface
Interface for -9-2LESampled Values
Interface for -8-1 GOOSE
-
8/10/2019 IEC 61850 Process Bus
28/53
IEDs for Process Bus ApplicationsRelays
Point to point connections
Feasible when all the SV required by a relay areavailable from a single MU
Simple network, minimum delay, minimalengineering effort
Interfacing SV to Relays
MiCOM P446
IEC 61850
MergingUnit 1
IA1, IB1, IC1
VA, VB, VC
-
8/10/2019 IEC 61850 Process Bus
29/53
Interfacing SV to Relays Transformer
Protection
P645
HV+LV+TV
HV Current - 1
HV Current 2
TV Current - 1
TV Current - 2
LV Current
Point to point
connection
not possible
Point to point
connection
not possible
IEDs for Process Bus ApplicationsRelays
-
8/10/2019 IEC 61850 Process Bus
30/53
IEDs for Process Bus ApplicationsRelays
Networked connections
Required if the SV required by a relay are from multiple MU,eg: transformer IED, busbar IED
Ethernet switch(es) involved, possibility of additional delays
and sample jitter; substation-hardened switches required,similar to Station Bus applications.
Interfacing SV to Relays
-9-2LE
-
8/10/2019 IEC 61850 Process Bus
31/53
IEDs for Process Bus ApplicationsRelays
Networked connections - redundancy
Network redundancy for SV may be achieved by externaldevices such as a RedBox, or it may be integral to the relay
Note that network redundancy only accounts for
communication link failures
Interfacing SV to Relays
LAN A
LAN B
-
8/10/2019 IEC 61850 Process Bus
32/53
Interfacing SV to Relays
Settings for relay / MU configuration Logical Nodes
Number of MU could vary with application
IEDs for Process Bus ApplicationsRelays
-
8/10/2019 IEC 61850 Process Bus
33/53
IEDs for Process Bus ApplicationsMerging Units
Merging units perform all the digital data processing necessary to produce aprecise, time-aligned output data stream of sampled values according to the
IEC 61850-9-2 standard
Includes tasks such as sampling, analogue to digital conversion, scaling,precise real-time referencing to the start of the last second and messageformatting
Design varies with the applied technology of the instrument transformers (eg:optical, Rogowski, voltage dividers, or conventional wound instrumenttransformers), the switchgear type and mounting space available
Alstom Grid portfolio will cover such solutions, for application in new
substations with digital NCITs, as well as refurbishments of olderconventional substations, or partial replacement by new sensors.
-
8/10/2019 IEC 61850 Process Bus
34/53
FUNCTIONALITY TRANSFERRED
TO AN ANALOGUE MERGING UNIT
FUNCTIONALITY TRANSFERRED
TO A DIGITAL MERGING UNIT
IEDs for Process Bus ApplicationsMerging Units - Functionality
-
8/10/2019 IEC 61850 Process Bus
35/53
IEDs for Process Bus ApplicationsMerging Units - Mounting
APPS 2012 Stafford UK
Located in the switchyard in the case of AIS Close to primary eqpt, inside LCC, for instance
Fibre optic cabling for protection signals
-
8/10/2019 IEC 61850 Process Bus
36/53
IEDs for Process Bus ApplicationsEthernet Switches
What are the requirements for switches on Process Bus ?
Industrial, substation-hardened
Switches should be managed, to optimise LAN performance
Check the number of Fibre / Copper ports available and compare
with the application requirements
Switches should be VLAN-aware
Switches that are transparent clocks for IEEE 1588, where requiredfor time synchronisation
!! Protection scheme is dependent on switches !!
Typically, switches would be located with protection / BCU
Other IEDs may, optionally, integral a switch board
APPS 2012 Stafford UK
IED f P B A li i
-
8/10/2019 IEC 61850 Process Bus
37/53
IEDs for Process Bus ApplicationsEthernet Switches
IEC 61850-3 : Switches , like relays, should comply with the
type withstands tests designed to simulate substation EMIphenomena such as:
Lightning impulses
Switching of inductive loads
Electrostatic discharges
Radio frequency interference due to portable radio handsets
Earth potential rise resulting from system fault conditions
APPS 2012 Stafford UK
IED f P B A li i
-
8/10/2019 IEC 61850 Process Bus
38/53
IEDs for Process Bus ApplicationsEthernet Switches
IEEE 1618 : Standard for Environmental and Testing
Requirements for Communications Networking Devices in
Electric Power Substations
Defines optional Class 2 - requires that, during the
application of the type tests, the switch must exhibit:
No communications errors
No communications delays
No communication interruptions
APPS 2012 Stafford UK
IED f P B A li ti
-
8/10/2019 IEC 61850 Process Bus
39/53
IEDs for Process Bus ApplicationsEthernet Switches - Example
Cascading H356 for additional ports
4 x LC Multimode
2 x RJ45
APPS 2012 Stafford UK
-
8/10/2019 IEC 61850 Process Bus
40/53
Scope
IEDs for Process Bus Page 26
hi l
-
8/10/2019 IEC 61850 Process Bus
41/53
Process Bus Architecture ExamplesSingle AMU-DMU
Process Bus
IEC61850-8.1 and 9-2
Ethernet 100 Mbps
BCU MP2 MP1
Note: Conceptual architecture only,
the functionality of MP1, MP2 etc. is unspecified
-9-2-8-1
Control Room
Switchyard / GIS Room
Separate networks for-8-1 and -9-2
One CT core, SVdistributed by singleAMU
Status / trips viasingle DMU
Single AMU / DMU,thus failure affects fullprotection & control ofthe bay
Switch failure affects
full protection andcontrol of the bay
Substation Grade
Ethernet Switch
AMUDMU
ESW ESW
ESW
APPS 2012 Stafford UK
P B A hi E l
-
8/10/2019 IEC 61850 Process Bus
42/53
Process Bus Architecture ExamplesDual AMU-DMU
Process Bus
IEC61850-8.1 and 9-2
Ethernet 100 Mbps
BCU MP2 MP1
Note: Conceptual architecture only,
the functionality of MP1, MP2 etc. is unspecified
-9-2-8-1
Control Room
Switchyard / GIS Room
Main 1 and Main 2protections haveindependent AMU and
DMU, separatenetworks
SV and GOOSE forBCU and MP2 sharecommon switch
Independent CT coresfor Main 1 and Main 2via AMU1 and AMU2
Two independent tripoutputs available DMU1 and DMU2
Substation Grade
Ethernet Switch
AMUDMU
ESW
ESW
AMU
DMU
-9-2 -8-1
APPS 2012 Stafford UK
-
8/10/2019 IEC 61850 Process Bus
43/53
Time synchronisation for sampled values
Distribution of busbar voltage for check sync
Merging Unit with redundant ports
IEDs with redundant ports for Process Bus
Merging Unit common for analogues and digitals
Process Bus Architectures
Whats missing in the previous architectures ?
> Architecture must be optimised for the application