May 20, 2021 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) © 2021 SEL Introduction ▪ System background ▪ Distributed vs Centralized ▪ Emergency Control System ▪ Reliable Communications requirements ▪ The future of GSE’s ▪ Contingencies considered Emergency Control System System Background Centralnaia Russia Enguri Jvari Imereti hydro Stepantsminda 500 kV powerplant Georgia 220 kV Kartli-2 Tbilisi Zestaponi Black Kartli-1 Sea Zekari Ksani Akhaltsikhe 110 kV Vardzia Asureti Mukhranis Veli 110 kV 400 kV Marneuli Borhkha Gachiani 330 kV Alaverdi Samukhi Turkey Armenia Azerbaijan Power System Stability “... 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 Generation Loads Supply Demand GSE Power System Instability V V S P R X P P State 0 t VS VR X500 State 0 X220 P0 P VS VR State 1 X500 State 1 X220 0 0 180 Emergency Control System Benefits System Installed in 2011 Year Blackouts Brownouts Total • Economic 2014 14 11 25 and social 2015 2 16 18 • Power system 2016 9 15 24 stability 2017 10 8 18 2018 9 15 24 2019 5 13 18 2020 6 34 40 2021* 4 5 9 *As of April 2021 Contingencies Considered • 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 load after contingency) • Validation through accurate simulation models Distributed vs. Centralized Architecture Distributed Contingency 1 Action Logic / Rules Equipment Contingency 2 Logic / Rules Original Emergency Control System To Russia Zestaponi Ksani PIme PKr2 Imereti Kartli-2 Enguri C2 GSC1 C1 LSC1 Ethernet Switches LSC7 Distributed Architecture Details Component No. Possible Actions • Load and generator shedding 500 kV line 8 HVdc control • Load shedding 500 / 400 / 330 kV • Generator shedding if exporting interconnection 5 • HVdc control lines Disconnection of other interconnecting lines 220 kV lines 1 • Load and generator shedding Autotransformers 2 • Load and generator shedding • Load shedding if importing HVdc converters 2 • Generator shedding if exporting Generators 6 • Load shedding and HVdc control Distributed vs. Centralized Architecture Centralized GSE operates both schemes Central Controller Contingency 1 Logic / Rules Contingency 1 Contingency 2 Logic / Rules Detection Equipment Action Equipment Contingency 2 Detection Equipment Load Shedding Controller Logic HMI Trip Level – Trip Level A Based on A B Precontingency B Power Flow Subscribed to Contingency Trip Feeder Detection Controller HMI ▪ System overview ▪ Thresholds and settings (SCADA complement) ▪ Alarms and status Generator Shedding Logic Measured MW in HVdc MW to Shed Based on State of + Select Combination of Power System S Generators to Trip and Contingency – Detection Controller START Subscribed to Contingency ECS Contingency Detected 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 ECS ECS system will become completely independent of SCADA. Connection to GSE SCADA will be removed. Antenna Antenna VT Antenna VT Antenna Clock VT Clock VT CT Clock CT Clock SEL-2240 Contingency CT SEL-2240 Contingency CT DetectionDetection Equipment SEL-451 Contingency DetectionDetection Equipment SEL-451 Contingency Breacker DetectionDetection Equipment DetectionDetection Equipment Breacker Generators Generators Breacker SEL-2440 SEL-2440 SEL-1102Central Central Controller SEL-1102Central Central Controller ActionAction Equipment ActionAction Equipment ContingencyController Logic / Rules ContingencyController Logic / Rules VT SCADA MeasureSEL-2240 SCADA Axion CT CT CT Measurement Existing Measurement Future Trip Trip Trip Trip Trip Trip Load Load Load Load Load Load 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/ [email protected].