MIGRATE Wide Area Control in Landsnet Iceland December

MIGRATE Wide Area Control in Landsnet, Iceland December 6, 2020 Confidential. Not to be copied, distributed, or reproduced without prior approval.

WAC Targets Typ spl ica it l l ine s System responsive control to ride through disturbances Islanding Reduce occurrence by fast stability response Minimise impact by improved island balance Security of Supply Reduce number and duration of outages Reduce frequency excursions & trips Extended use of network Large loss Unequal acceleration à Transient angle and frequency difference à Islanding 0. 5 Hz Frq difference Increase capacity of existing transmission Offer new managed connections Presentation Title Confidential. Not to be copied, distributed, or reproduced without prior approval. 0. 6 s Frq Delay across system December 6, 2020 2

MIGRATE Targets Demonstrate Synchrophasor-Based System Response Control • Demonstrate new system-responsive control Discrete control fast triggered load step e. g. East Iceland Load Shed, NAL Fast ramp control fast triggered gen/load ramp e. g. HRA Intelligent splitting split choice for island balance e. g. SIG • Proportionate to event, sensitive to location • Implement with existing WAMS infrastructure, recommend for progression • Repeatable process, can replicate for new service providers MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 3

Comparing Wide Area Defence with SIPS WA Defence as a generalised form of SIPS, treating stability response as a service + - - EVENT DRIVEN SIPS Very fast event-driven logic, acts before system responds Inherently over-responds Cannot account for all contingencies Unintended interaction between SIPS Typically requires a few large, predictable resources to actuate RESPONSE DRIVEN WA DEFENCE + Responds proportionately to needs + Robust to unplanned contingencies + Distributed control with many service providers & diverse resources - Acts only in timeframe that system responds HYBRID In Iceland, disturbances are often a chain of multiple events, difficult to plan for all contingencies. Also, need to keep generation running, and not trip it, for successful islanding and rapid load restoration. Thus, conventional SIPS is not viable. MIGRATE WAC in Landsnet, Iceland + Fast event-driven initial under-response followed by response-driven + Derives benefits of both approaches General response to counteract event sequences, drawing from resources available from connected loads and generation. ‘Hybrid’ can trigger a directly response to a specific event, followed up by a system response. E. g. smelter load trip directly triggers load step up, before system response starts (ramp, discrete, split). Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 4

53 52 51 51 East Frequency A 50 D T=1. 1 s E T= 1. 2 s Area angles separated by 70º, resulting in high E-W power. One route opens by special protection Areas accelerate away from each other; synchronism is lost and system islands B C West Angles Angle Difference (deg) T=0 s Industrial load #1 reduction (first stage) T=0. 2 s Industrial load #1 reduction (second stage) T=0. 36 s Industrial load #2 trip D ΔT=0. 3 s 50 A B C E 100 Δδ=70º 52 ΔF=0. 28 Hz Frequency (Hz) West Frequency E D 0 East Angle -100 Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020

WACS in operation Gen 1 Phasor. Point Wide Area Control Schemes East Load Shed Triggered load shed Smelter Ramp Control Down action Smelter Step Control Down&Up fast action “Green Button” Islanding Split 5 gens & smelter load 220 k. V lines 132 k. V línes 66 k. V lines 33 k. V lines Substations Industrial loads MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 6

WACS targets (~1 year, MIGRATE, ISAL & other tentative) Gen 2 Phasor. Controller System Responsive WAC Principle MIGRATE Scope Load Shed Triggered load shed Smelter Ramp Control Down action Smelter Step Control Down&Up fast action Intelligent splitting More stable islands created Generator Fast Ramp Location-sensitive event trigger 220 k. V lines 132 k. V línes 66 k. V lines 33 k. V lines Substations Industrial loads MIGRATE WAC in Landsnet, Iceland • Principles and repeatable methodologydesigned and proven for fast stability control • Load & generation services utilised • Phasor. Controllerreal-time platform, control architecture and fast comms network Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 7

Distributed Wide Area Control Architecture Distributed Control System – Unified System View shared between Distributed Control Units 3 2 1 ZONES Centres of inertia represented by aggregate frequency & angle measurement Zone Aggregate SHARED with all Control Units MIGRATE WAC in Landsnet, Iceland CONTROL UNITS Initiate response proportionate to event, self-limiting and sensitive to islanding state. TRIGGEREDor RAMP responses of resource applied Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 8

Distributed Wide Area Control Principle Distributed Control System – Unified System View shared between Distributed Control Units 2 a Instantaneous imbalance in Zone; angle starts to move. 1 Fault occurs, load balance changes in Zone 2 b Initially, no angle movement in remote Zones; no instantaneous change in P between zones. 3 2 1 MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 9

Distributed Wide Area Control Principle Distributed Control System – Unified System View shared between Distributed Control Units 3 b Growing angle difference leads to growing power between Zones 3 c P exchange between zones due to growing power flow into zone. Angles and frequency start to move. 3 a Frequency increases, angle continues to move 4 Phasor. Controller(s) in Z 1 detects event (SROCOF), enables response in Z 1 (angle), and triggers DISCRETE load step up and generation RAMP down. Power rebalance counteracts angle & freq movement. MIGRATE WAC in Landsnet, Iceland 3 2 1 Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 10

Distributed Wide Area Control Principle Distributed Control System – Unified System View shared between Distributed Control Units 5 c Growing angle difference leads to growing power between Zones 6 P increases to level to trip SPS at BLA, opening ring. 5 a Frequency increases, angle continues to move, slowed by control action 3 2 WAC process complete once frequency gradient reaches zero for the part of the system connected. 1 5 b Z 1 Ramp continues, reducing imbalance until frequency peaks MIGRATE WAC in Landsnet, Iceland 7 Ph. C splitting decision puts SIG generators on East, if splitting is inevitable. Helps balance both E and W islands. Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 11

Simulation results Example of large load loss with WAC resources applied Action Peak Frequency(excluding oscillations) Base case, split at BLA/HOL Case fails at 1. 7 s from fault, with west frequency accelerating Split at BLA/SIG 1. 023 pu (51. 15 Hz) Split at BLA/SIG +30 MW load step up in West 1. 020 pu (51. 00 Hz) Split at BLA/SIG HRA 1&2 ramp down in West No load action 1. 018 pu (50. 90 Hz) Split at BLA/SIG HRA 1&2 ramp down in West +30 MW load step up in West 1. 015 pu (50. 75 Hz) Split at BLA/SIG HRA 1&2 ramp down in West BUR 56 ramp down in West +30 MW load step up in West 1. 011 pu (50. 55 Hz) MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 12

Discrete and Continuous Control Combined effect limits extent of frequency movement MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 13

Intelligent Splitting logic at Sigalda Proposed SIG Logic If (P 1>W) & (P 2>X), open B 1 near-instantaneously If (P 2<-Y), open B 2 near-instantaneously If (|P 2|>Z) for T sec If (P 2<-Z), open B 1 If (P 2>Z), open B 2 HOL SIG BLA HOL SIG MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 14

Phasor. Controller as Key Building Block Flexible real-time phasor-capable control platform is key enabler Supports standard protocols Phasor. Controller Core Software Framework Synchrophasor Data In C 37. 118/IEC 61850 -90 -5 Event/Status/Control Input IEC 61850 GOOSE IN/Hardware Inputs Data Management Data subscription, concentration, time-alignment quality, configuration and publication. Real-Time Scheduling Engine Function Block 1 Function Block 2 … Function Block n Synchrophasor Data Out C 37. 118/IEC 61850 -90 -5 IEC 60870 -5 -104 IEC 61850 IEEE C 37. 118 Modbus Digital I/O's Other Control Commands Out IEC 61850 GOOSE OUT/IEC 60870 -5104/ Hardware Outputs Application Functions Blocks Standard & Custom Library of Elements Flexible for scheme designs Encapsulates complex processes in modular design Implemented in a standard PLC environment MIGRATE WAC in Landsnet, Iceland Angle Difference Frequency Difference Look Up Table Gen/Load SIPS Arming Correlation Phasor Aggregation Disturbance Location Rate of Change Islanding Detection Oscillatory Instability Detection SSO Instability Detection Voltage Instability Detection Projected Angle Difference P/Q Calculation Sine Wave Generation PID Control 20 ms Cycle Time Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 15

Nordural Smelter Load Control Example of load upward step Smelter added P response High frequency disturbance Location identified in SW ZONE (response unblocked) 20 MW Load increase triggered Start 0. 5 s from event Sustained till after frequency stabilised (10 s) Slow ramp down Frequency peak reduced by ~0. 25 Hz Effect multiplied with several distributed resources Reduced regional angle separation MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 16

Summary Overview of WAC Targets Control of loads • Triggered fast control Load regulation Load tripping • Goal to prevent system split and/or balance within disturbance area Fast ramping generating units • Faster response within disturbance area, reducing frequency change • PMU based blocking of change over to frequency mode • Emergency control in AGC Intelligent Islanding • Split-line armed depending on power flow and balance • Intelligent splitting points at generator buses • Increased power flow on 132 k. V ring MIGRATE WAC in Landsnet, Iceland Confidential. Not to be copied, distributed, or reproduced without prior approval. December 6, 2020 17