Restoration Concepts PEAK RC Training Classification: Confidential Version No.: 1.5 Date of Document: Document Owner/Author: B Pederson Classification: Version No.: 1.1 Date of Document: 8/2015 Document Owner/RC Training Dept.

2 Recognize system conditions requiring the application of the RC Restoration Plan. Learning Objectives Determine when System Restoration begins and ends. Identify the duties of the RCSO during System Restoration. Describe the modes of AGC and when they will apply during system restoration.

3 Recognize Ferranti Effect and methods to reduce effects in transmission system. Learning Objectives Recognize Surge Impedance Loading (SIL). Identify requirements for “Return to Normal Operations”. Describe “Zero Droop” and the effects of load sharing in an islanded condition.

4 o Blackstart Resources are utilized to re-energize a shut down area of the BES, or o Separation has occurred between neighboring RCs or with the Alberta Electric System Operator (AESO) Area, or o An energized island has been formed on the BES within the RC Area. or Additionally, the RCSO will consider the system to be in an operational emergency condition when any RC Area TOP has implemented their System Restoration Plan(s). System Conditions for RC Restoration Plan Implementation Scope

5 Coordination Monitoring of Progress Analyze / Stabilize / Restore / Return to Normal Operations - Discussion RCSO Roles and Responsibilities

6 Identification of Boundaries o What frequency sources are available? o Are the frequency sources within the island(s) or outside of the island(s)? o How will accurate values be determined? Synchronizing / Paralleling

7 Islands Frequency Sources Balancing Area Frequency Sources ?

8 How will progress be tracked (map, video wall)? o Ideas? Regional maps available with ability to annotate? o If on video wall do we know how to log into and manipulate displays? Progress Tracking

10 Transmission Lines, Surge Impedance Loading (SIL), and Ferranti Rise SIL: MVAR produced = MVAR consumed  During normal operation, transmission lines are operated above Surge Impedance Loading (SIL)  Lines absorb vars and tend to lower system voltage  Generator or Capacitors are used to supply these VARs  During the early stages of restoration, many (if not all) of the lines energized will be operated below (SIL)  The lines produce VARs and tend to raise system voltage  This is known as “Ferranti Rise” or “Ferranti Effect”  Generators or Reactors are used to absorb these VARs Surge Impedance Loading (SIL) and Ferranti Rise

11 VSVS To Power System To Power System ClosedOpen Maximum Voltage Will Occur at Open End VARS Flow of Leading Charging Current Leads to a Gradual Voltage Rise Voltage Profile Along Line Closed Ferranti Rise Voltage Profile with both breakers closed VRVR VARS

12 Surge Impedance Loading 0.25 MVAR per mile for 230 kV 0.75 MVAR per mile for 345 kV 2.0 MVAR per mile for 500 kV

13 Governor Droop

Governor Droop 5% Hz Governor droop for different units Load (red box) sharing

Hz MW Governor Droop % 1% Load sharing between units of different sizes and droop settings

% Droop Units with “0” Droop Unit Hz MW 5% 0%

Manual Governor Operation 153 Hz 5%

18 Questions ? Next: Generation Operation - AGC

19 ACE = (NI A - NI S ) - 10β (F A - F S ) – I ME Modes of AGC Operation: Tie-line Bias: Utilizes all of the variables in the ACE equation to control generation ACE = (NI A - NI S ) - 10β (F A - F S ) Frequency Bias: Utilizes the frequency portion of the ACE equation for generation control (no schedule component) 10β (F A - F S ) Constant Net Interchange: Utilizes the schedules portion of the ACE equation for generation control (no frequency component) (NI A - NI S ) Area Control Error (ACE) / AGC

AGC (Flat Frequency) - Governor Operation Hz Flat FrequencyGovernor Operation Adding 20 MW of load both systems share. The system in AGC (FF) responds to return frequency to 60 Hz and picking up the 20 MW of load added.

AGC (Constant Net Interchange) - (Constant Net Interchange) Hz Constant Net Interchange Adding 20 MW of internal load, both systems share. The system in which the load was added responds by picking up the 20 MW of load added. Frequency is not returned to 60 Hz though.

AGC (Flat Frequency) – (Flat Frequency) Hz Flat Frequency Adding 20 MW of internal load, both systems share. Both systems try to return frequency to 60 HZ but will overshoot and magnify the frequency delta from 60 Hz.

AGC (Flat Frequency) – (Constant Net Interchange) Hz Flat Frequency Constant Net Interchange Adding 20 MW of internal load, both systems share. FF system works to return frequency to 60 HZ while the CNI system adjust for Interchange. Overshoot occurs but will return to 60 Hz.

AGC (Tie Line Bias) – (Constant Net Interchange) Hz Constant Net Interchange Tie Line Bias Adding 20 MW of internal load, to CNI, both systems share. The system in TLB responds to return frequency to 60 Hz and CNI picks up the 20 MW of load that was added. Eventually settles out to 60Hz.

AGC (Tie Line Bias) – (Flat Frequency) Hz Tie Line BiasFlat Frequency Adding 20 MW of internal load, both systems share. The system in TLB responds to return frequency to 60 Hz and schedule, FF controls to 60Hz. Result is overshoot but settles out to 60 Hz

26 Assumptions: All RC Area TOPs that have the capability to be interconnected are interconnected and operating synchronously. The interconnected RC Area TOPs are connected to the Alberta System or the Eastern Interconnection as appropriate. The RCSO has verified that the RC Area BES is in a stable state Transitioning to “Normal Market Operations”

27 Assumptions (cont’d): The RCSO has verified with all RC Area BAs and TOPs that they are ready to return to normal operations mode. The RCSO has verified the status of adjacent interconnections with the adjacent Reliability Coordinators and AESO and has confirmed that adjacent interconnections are ready to return to normal operations mode with RC Area operating entities. Transitioning to “Normal Market Operations”

28 Priorities: The RCSO has verified that the cause of the disturbance that initiated the restoration event is known and is no longer a threat to the BES. The RCSO has verified that all major load centers have been restored prior to returning to normal operations. Actual BES line flows and contingency analysis results should indicate that the BES is operating within applicable System Operating Limits (SOLs) and Interconnected Reliability Operating Limits (IROLs). Transitioning to “Normal Market Operations”

29 General Procedures: The RCSO shall communicate with all RC Area BAs and TOPs (or their designated agent) and verified the status of their systems and that they are ready to return to normal operations. The RCSO shall contact AESO and the neighboring RCs to verify that the neighboring RC Areas and adjacent operating entities are ready to resume normal operations with the RC Area’s operating entities. The RCSO shall issue a message on WECCNet and RCIS messaging systems announcing a return to normal operations. Transitioning to “Normal Market Operations”

Questions/Discussion

31 VersionDateActionByChange Tracking 1.008/13/2015New TrainingPatrick Olin 1.108/30/2015 Converted into correct Peak template for Fall 2015 RC Training. Captivate version removed. Patrick Olin Approved: ______________________ RC Training ManagerDate Signed VERSION HISTORY: Versioning History Signature Page Classification: Version No.: 1.1 Date of Document: 9/15/2015 Document Owner/Author: RC Training