country-wide distributed emergency control systems of the
TRANSCRIPT
© 2021 SEL
Country-Wide Distributed Emergency Control Systems of the Transmission Network in the Republic of Georgia
Alexander Didbaridze and Vladimer Korganashvili
Georgian State Electrosystem (GSE)
Eduardo S. Palma
Schweitzer Engineering Laboratories, Inc. (SEL)
May 20, 2021
▪ System background
▪ Emergency Control System requirements
▪ Contingencies considered
▪ Distributed vs Centralized
▪ Reliable Communications
▪ The future of GSE’s Emergency Control System
Introduction
Ksani
Akhaltsikhe
Centralnaia
Turkey AzerbaijanArmenia
Russia
500 kV220 kV
Stepantsminda
110 kV
110 kV
330 kV
400 kV
Zestaponi
Marneuli
Georgia
Black
Sea
Enguri
hydro
powerplant
Jvari
BorhkhaAlaverdi
Kartli-2
Imereti
Zekari
Vardzia
Kartli-1
Asureti
Gachiani
Mukhranis Veli
Samukhi
Tbilisi
System Background
“... is the ability of an electric power system, for a given initial operating condition, to regain a state of operating equilibrium after being subjected to a physical disturbance, with most system variables bounded so that practically the entire system remains intact.”
—lEEE / CIGRE Task Force
Power System Stability
Power System Stability
Loads
Demand
Generation
Supply
P
X
VS VR
GSE Power System Instability
X500
VS VR
State 0
PVS VR
X220State 1
P
X500
X220
t
P State 0
180
0 0
State 1
P0
Emergency Control System BenefitsSystem Installed in 2011
*As of April 2021
• Economic and social
• Power system stability
Year Blackouts Brownouts Total
2014 14 11 25
2015 2 16 18
2016 9 15 24
2017 10 8 18
2018 9 15 24
2019 5 13 18
2020 6 34 40
2021* 4 5 9
• N-1 criterion
• Highly probable contingencies (e.g., loss of line)
• Power system studies performed
• Angular instability and overloads
• Coordination with neighboring countries
• Emergency control actions (balancing generation and loadafter contingency)
• Validation through accurate simulation models
Contingencies Considered
Distributed vs. Centralized ArchitectureDistributed
Contingency 1
Logic / Rules
Contingency 2
Logic / Rules
Action
Equipment
Original Emergency Control System
C2C1
Ethernet
Switches
GSC1
LSC1
LSC7
PIme PKr2
Enguri
Zestaponi Ksani
Imereti
To Russia
Kartli-2
Distributed Architecture Details
Component No. Possible Actions
500 kV line 8• Load and generator shedding
HVdc control
500 / 400 / 330 kV
interconnection
lines
5
• Load shedding
• Generator shedding if exporting
• HVdc control
Disconnection of other interconnecting lines
220 kV lines 1 • Load and generator shedding
Autotransformers 2 • Load and generator shedding
HVdc converters 2• Load shedding if importing
• Generator shedding if exporting
Generators 6 • Load shedding and HVdc control
Distributed vs. Centralized ArchitectureCentralized
Central Controller
Contingency 1 Logic / Rules
Contingency 2 Logic / Rules
Contingency 2
Detection Equipment
Action Equipment
Contingency 1
Detection Equipment
GSE operates
both schemes
Load Shedding Controller Logic
HMI
Trip Feeder
Trip Level
–
A B
A
B
Trip Level
Based on
Precontingency
Power Flow Subscribed to Contingency
Detection Controller
▪ System overview (SCADA complement)
▪ Thresholds and settings
▪ Alarms and status
HMI
Generator Shedding Logic
MW to Shed
Based on State of
Power System
and Contingency
ECS Contingency
Detected
Detection Controller
Subscribed to Contingency
Measured MW
in HVdc
+
–
Select Combination of
Generators to Trip
START
S
Communications Network Considerations
▪ Use Optical Ground Wire (OPGW) infrastructure
▪ Cybersecurity
– Use of firewalls
– Secure login
– Secure, complex device passwords
▪ Careful traffic engineering
▪ Traffic segregation
▪ Time distribution
ECS Communication Network
▪ Synchronous Multiplexers allow separate Ethernet bandwidth:
– One bandwidth routes critical GOOSE messages
– Second network bandwidth routes TCP/IP traffic
▪ Multiplexers distribute precise time synchronization
▪ Ring networks provide redundancy
Work planned for the future of the ECSECS system will become completely independent of SCADA.
Connection to GSE SCADA will be removed.
SEL-451 Contingency
Detection Equipment
CT
VT
Breacker
SEL-2440
Action Equipment
Trip Load
Trip Load
Trip Load
Clock
Antenna
SEL-1102 Central ControllerContingency Logic / Rules
SCADA
Measurement
SEL-2240 Contingency
Detection Equipment
CT
VT
Generators
Clock
Antenna
Existing
SEL-451 Contingency
Detection Equipment
CT
VT
Breacker
SEL-2440
Action Equipment
Trip Load
Trip Load
Trip Load
Clock
Antenna
SEL-1102 Central ControllerContingency Logic / Rules
SCADA
Measurement
SEL-2240 Contingency
Detection Equipment
CT
VT
Generators
Clock
Antenna
Future
SEL-2240Axion
VT
CT CT CT
BreackerDetection Detection Detection
Detection
Action ActionCentral
Controller
Central
Controller
Measure
Work planned for the future of the ECS
The Synchrophasor Metering System
(SPM) project
Wide Area Monitoring System
(WAMS)
Questions?
https://selinc.com/Solutions/Success-Stories/Republic-of-Georgia/