1 Overview

2 Benefits of RATC Applications Real-time corrective Hour ahead corrective and preventive Day ahead corrective Day ahead market/economic based RATC algorithms

3 Benefits of RATC Market models (day-ahead, hour-ahead) do not guarantee N-1 feasibility RATC reduces contingency violations RATC reduces costly out of market corrections Market Model Contingency Analysis Out of Market Corrections

4 Benefits of RATC with Renewables Renewable resources Renewables impose locational reserve requirements RATC improves reserve deliverability, reduces need for investment in local generation RATC minimizes costly re-dispatch caused by renewables Enables higher percentage levels of renewables

5 Expected RATC Benefits Cost savings: >2-5% avoided costs System reliability N-1, N-m, malicious attacks can be mitigated using real-time RATC Reduction in load shedding: >5-10%

6 Real-Time Corrective

7 Real-time Structure Computational time: < 5 min.

8 Real-time Corrective Algorithm

9 Real-time Corrective Topology Control Examples PJM (2010) Manual 3: Transmission Operations. operations/compliance/nerc- standards/~/media/documents/manuals/m03.ashx Sunnyside-Torrey 138 kV Operating Guide (AEP Operating Memo T029) – Historically, the Sunnyside-Torrey 138 kV overloads on the outage of the South Canton – Torrey 138 kV line. Opening the S.E. Canton 138 kV CB at Sunnyside will help to reduce the post-contingency flow on the Sunnyside-Torrey 138 kV line. – Page 107

10 Superstorm Sandy PJM lost 82 bulk electric facilities – 6 500kV transmission assets ; 3 345kV transmission assets ; kV transmission assets ; kV transmission assets Caused extremely high voltage on the system during low load levels We were dealing with extremely high voltage on the system but a switching plan was developed to help alleviate these conditions. Via Andy Ott, VP of PJM: several 500kV lines were switched out to mitigate over voltage concerns during these low load level periods

11 Hour Ahead Corrective

12 Hour Ahead Corrective Structure Computational time: < 15 min.

13 Hour Ahead Corrective Algorithm (Renewables)

14 Hour Ahead Corrective Results IEEE 118-bus Test Case Wind uncertainty: ±16% Reserve: 5% non-wind + 10% wind or largest contingency Results to date from IEEE 118: RATC produces multiple candidate switching actions for single events/contingencies Candidate switching actions solve multiple events Market solution (without RATC) failed N-1 contingency analysis with forecasted wind level Market solution with RATC is N-1 reliable and robust against renewable uncertainty

15 Hour Ahead Preventive

16 Hour Ahead Preventive Structure Computational time: < 15 min.

17 Hour Ahead Preventive Algorithm (Renewables)

18 Day Ahead Corrective

19 Day Ahead Corrective Structure Computational time: 2-3 hrs.

20 Day Ahead Corrective Algorithm

21 Hour Ahead Corrective Results IEEE 118-bus Test Case Demand uncertainty: ±6% Reserve: 5% hydro + 7% non-hydro or largest contingency Results to date from IEEE 118: RATC produces multiple candidate switching actions for single events/contingencies Candidate switching actions solve multiple events Market solution (without RATC) failed N-1 contingency analysis with forecasted demand Market solution with RATC is N-1 reliable and robust against demand uncertainty

22 Day Ahead Market/Economic Based

23 Day Ahead Market Based Structure Computational time: 2-3 hrs.

24 Day Ahead Market Based Algorithm

25 Day Ahead Market Based RATC Results

26 RATC Algorithms

27 Topology Control Algorithms Greedy algorithm Based on a sensitivity analysis Fast, scalable algorithm for large-scale systems Medium to short-term RATC applications MIP heuristic Finds the best single switching action Long to medium-term RATC applications

28 Greedy Algorithm

29 MIP Heuristic

30 Test Systems IEEE Test Systems PJM Dataset via FERC TVA