Generic and Adaptive System Restoration Methodology: Towards a Self-Healing Smart Grid

Transcription

1 Generic and Adaptive System Restoration Methodology: Towards a Self-Healing Smart Grid Dr. Yunhe Hou Department of Electric and Electrical Engineering The University of Hong Kong yhhou@eee.hku.hk PowerCon 2014 Supported by: Electric Power Research Institute, USA National Science Foundation, China RGC General Research Fund, Hong Kong

2 Power System Restoration: Basic Concept Following a complete or partial outage, dispatchers in the control center work with field crews to re-establish the generation and transmission systems and then to pick up load and restore service

3 Power System Operating States Preventive Control Restorative Control Corrective Control Cascade Events Emergency Control Tom DyLiacco

4 State of the Art Primarily manual work by dispatchers Off line restoration planning Little progress made on on-line or offline decision support tools for system restoration On line implementation limited Literature

5 Outline Systematic restoration methodology Constraints for system restoration System Restoration Navigator Breaker-based system restoration Self-healing function discussion

6 Outline Systematic restoration methodology Constraints for system restoration System Restoration Navigator Breaker-based system restoration Self-healing function discussion

7 Requirements of Systematic Restoration Methodology Generic Restoration Decision Support Toolbox Deferent strategies of restoration can be established within one framework Adaptive Restoration Decision Support Toolbox Strategy of restoration can adapt different scenarios

8 Challenges for Generic Restoration Strategy Construction Policies System Characteristics Constraints Strategy-Oriented Objective-Oriented Oriented

9 Restoration Process Preparation System Restoration Load Restoration Optimal Generator Start-up Sequence to Maximize Overall System Generation Capability Optimal Transmission Path Search and Power Flow Check to Implement the Sequence Optimal Load Pick-up Sequence to Minimize Unserved Load

10 Generic Restoration Milestones (GRMs) GRMs Synchronize Islands Restoration System Restoration Returns to Normal Operation Connect Islands Pick up Load Establish Transmission Grid Find Path to Crank Non Black Start Units Start Black Start Units Sectionalizing 10 Ascertain System Status

11 Generic Restoration Milestones (GRMs) GRM1: Form BS_Non_BS Building Blocks GRM2: Build Electrical Island GRM3: Synchronize Electrical Islands GRM4: Establish Transmission Path GRM5: Serve Load in Area GRM6: Connect with Neighboring Systems Considering the system characteristics, a specific restoration strategy can be established by combining and sequencing of GRMs 11

12 GRMs for HQ strategy The structure of the Hydro-Quebec system is quasi-radial: two remote production sites in the northwest and east of Quebec are connected to the load in the southwest by long transmission lines GRM4: Establish Transmission Path GRM2: Build Electrical Island GRM3: Synchronize Electrical Islands GRM5: Serve Load in Area 12

13 GRMs for PJM / AEP strategy GRM1: Form BS_Non_BS Building Blocks GRM2: Build Electrical Island GRM3: Synchronize Electrical Islands GRM4: Establish Transmission Path GRM5: Serve Load in Area GRM6: Connect with Neighboring Systems 13

14 Power system restoration with GRMs

15 Outline Systematic restoration methodology Constraints for system restoration System Restoration Navigator Breaker-based system restoration Self-healing function discussion

16 Technical Constraints Steady state constraints» Steady state overvoltage and voltage control» Capability of the blackstart units to absorb reactive power from charging currents of transmission lines.» For each step of restoration, it is necessary to ensure feasibility and compliance with operational limits. Dynamic constraints» Transient overvoltage» System stability

17 Characteristics of generating units Type Cap. (MW) Startup req. (MW) Ramp. Rate (MW/hr) Min Output (%) Crank to paral. (hr) Crit. max. int. (hr) BS/NBS C R k α% T1 T2 T3 Crit. min. int. (hr) t

18 Actual generator MVAR capability M. M. Adibi and L. H. Fink, "Overcoming restoration challenges associated with major power system disturbances - Restoration from cascading failures," Power and Energy Magazine, IEEE, vol. 4, no. 5, pp

19 Initial Sources of Power Availability of Initial Sources: Minutes Success Probability Run-of-the-River Hydro 5-10 High Pump-Storage Hydro 5-10 High Combustion Turbine (CT) in 2 or 3 CTs Full or Partial Load Rejection Short G T 50% Low Frequency Isolation Scheme Short G T 50% Controlled Islanding Short Special Cases Tie-Line with Adjacent Systems Short Not Relied On

20 FCB vs. Non-blackstart Unit Output of the FCB unit can be reduced to the auxiliary power instantaneously from a normal operating condition without the disconnection from the network after a blackout. BS NBS FCB

21 FCB Units in Post-separation separation Controls

22 22 FCB Units in Restoration G1, G4: BS units G1: BS, G4: FCB Due to a large capacity of leading phase operation, FCB can absorb reactive power to regulate voltages to accelerate the restoration.

23 Energizing High Voltage Lines Causes of overvoltage» Energizing long HV, EHV and UHV lines» Inadequate energizing sources (On-line generating units to absorb VARs?)» Inadequate underlying loads (reactive load to absorb VARs?)

24 Core Algorithms Set 24

25 GRM1: Form Black_Start_Non _Black_Start Building Block To minimize the total duration for self-healing f (, ) min generating units S xi θs tx x fs 1( xj, θs+1) x θ i S i j

26 Finding Feasible Operating Points by OPF with Transient Stability Constraints ij min c( x) PG P ˆˆ L Re( V&. ( YV &&)) hx ( ) 0 ˆ ˆ G L Im(. ( )) Q Q V& YV && PG PG PG QG g( x) QG QG V V V Adjustment of each generating unit Power flow Limits of variables ij 0 ij ij Pi, j ij ij P i P P P P P P P new 0 i i i, j new 0 j j i, j P P new i M i P P m i m i j P M i P t new i t f P P new j m j P M i M m new Pj Pj Pj Standing angles involved in OPF Trajectory sensitivity technique 0 ij ij Pi, j ij ij P i P new 0 P i Pi Pi, j j max ij new 0 P j Pj Pi, j

27 Finding feasible operating points by OPF with transient stability constraints

28 Algorithms for GRM3~6 GRM3: Serve Load in Area GRM4: Synchronize Electrical Islands Finding path for synchronization Adjusting voltages and phase angles Closing breaks GRM5: Form Electrical Island Pickup loads, establish transmission path Adjusting voltages and phase angles GRM6: Connect with Neighboring System the voltage in the neighboring system cannot be adjusted

29 Checking Constraints with PSS/E Data interface and application program interface developed by using API processor of PSS/E 29

30 Outline Systematic restoration methodology Constraints for system restoration System Restoration Navigator Breaker-based system restoration

31 System Restoration Navigator The program has the following functional features: Following a complete or partial outage. Graphical user interface allows the user to enter or modify the input parameters, execution modules and view the outputs. Establish strategy automatically and interactively

32 Integration with Experts Knowledge Integration with experts knowledge Milestone/Priority

33 Hawaiian Electric Company (HECO) Bus Generator Line Transformer Dispatchable Load Find solution within 8 min

34 Outline Systematic restoration methodology Constraints for system restoration System Restoration Navigator Breaker-based system restoration Self-healing function discussion

35 Data Flow for Integration Restoration Plan Snapshot 1 (PSS/E format) Power grid data (PSS/E format) SRN Restoration Plan Snapshot 2 (PSS/E format) Operation sequence file Restoration Plan Snapshot n (PSS/E format)

36 Realization of the Restoration Strategies Restoration strategies generated by SRN: branch-bus model. Objective: realize the restoration strategies in substations, breaker-based model Significance: update the restoration strategies from an off-line decision support system to an on-line self-healing system

37 Develop the Interface Branch-bus model: the order of restoration bus Breaker-based model: the breaker operation

38 Equivalent Problem in Graphic Theory The weighted graph for substation Weighting criteria: the priority operation of breakers, the constraints of breaker operation Equivalent problem: the shortest path problem, Dijkstra algorithm

39 Case study In each step, the proposed approach is called to calculate the breaker operation sequence. For the first step, the transformer between buses 91 and 93 and the transformer between buses 91 to 94 should be restored. For the first restoration step:

40 Case Study Calculation result: the sequence of switching operations can be searched, which is

41 Outline Systematic restoration methodology Constraints for system restoration System Restoration Navigator Breaker-based system restoration Self-healing function discussion

42 Self-Healing Smart Grids The health of an electric system, like that of the human body, is determined in large part by the strength of its immune system by its ability to heal itself. It enables girds automatically to» anticipate vulnerability» mitigate risky events» restore from outages» assess risk of system status and operating actions

43 Infrastructure of a Self-healing Smart Grid

44 New Challenges in the Context of the Smart Grid Uncertainties associated with integration of new energy sources and grid status

45

46 References 1. S. Liu, Y. Hou, C. Liu, and R. Podmore, "The Healing Touch: Tools and Challenges for Smart Grid Restoration," Power and Energy Magazine, IEEE, vol. 12, pp , Y. Hou, C.-C. Liu, K. Sun, P. Zhang, S. Liu, and D. Mizumura, "Computation of Milestones for Decision Support During System Restoration," Power Systems, IEEE Transactions on, vol. 26, pp , C. C. Liu, W. Sun, Y. Hou, and S. Liu, "Putting into Practice the Dream of a Self-healing Smart Grid," IEEE Smart Grid Newsletter, September C. Peng, Y. Hou, C. Wang, and Z. Qin, "Constructing Breaker Sequence based System Restoration Strategy with Graph Theory," in Power and Energy Society General Meeting (PES), 2014 IEEE, Z. Qin and Y. Hou, "A Branch-and-cut Method for Computing Optimal Load Restoration Strategy Considering Transmission Network and Discrete Load Incremant " presented at the 18th Power system Computation Conference, Wroclaw, Poland, Y. Hou, Z. Qin, and J. Yan, "Constructing Restoration Strategies with Availability Risk Constraints," in Power and Energy Society General Meeting (PES), 2014 IEEE, L. En, W. Ning, Q. Zhijun, L. Haoming, and H. Yunhe, "Black-start strategy for power grids including fast cut thermal power units," in Power and Energy Society General Meeting (PES), 2013 IEEE, 2013, pp Y. Hou, S. Liu, and Z. Qin, "Construction of System Restoration Strategy with PMU Measurements," Energy Procedia, vol. 12, pp , Z. Qin, S. Liu, and Y. Hou, "Virtual Synchroscope: a novel application of PMU for system restoration," in Advanced Power System Automation and Protection (APAP), 2011 International Conference on, 2011, pp S. Liu, R. Podmore, and Y. Hou, "System Restoration Navigator: A decision support tool for System Restoration," in Power and Energy Society General Meeting, 2012 IEEE, H. Liu, X. Chen, K. Yu, and Y. Hou, "The Control and Analysis of Self-Healing Urban Power Grid," Smart Grid, IEEE Transactions on, vol. 3, pp , 2012.

47 Today s s Research: Restoration Following a complete or partial outage, dispatchers in the control center work with field crews to re-establish the generation and transmission systems and then to pick up load and restore service

48 Today s s Research: Restoration Scenario

49 Smart Self-Healing Grids The health of an electric system, like that of the human body, is determined in large part by the strength of its immune system by its ability to heal itself. It enables girds automatically to» anticipate vulnerability» mitigate risky events» restore from outages» assess risk of system status and operating actions

50 Today s s Accomplishment Preventive Control Restorative Control Corrective Control Cascade Events Emergency Control Tom DyLiacco

51 Tomorrow s s Challenges Uncertainties associated with renewable sources Operation strategies for new components New construction of network Green components Grey system

52 Today's Research for Tomorrow's Grid Methodology Functionality Renewables Implementation Today's Research Restoration Customized Off-line Switch-off Operation Tomorrow's Grid Self-healing Generic On-line Participation Planning & Operation

53 Today's Research for Tomorrow's Grid Methodology Functionality Renewables Implementation Restoration Customized Off-line Switch-off Operation Self-healing Generic On-line Participation Planning & Operation

54 Systematic Restoration Methodology Generic Restoration Decision Support Toolbox Deferent strategies of restoration can be established within one framework Adaptive Restoration Decision Support Toolbox Strategy of restoration can adapt different scenarios

55 State-of of-the-art PJM Build-upward with serve critical Starting black start units Cranking non-black start units Restoration of islands Synchronization of islands Tie line requests: buildinward and build-outward Hydro-Quebec Build-downward Remote generation sites connected to the load through long transmission lines Overvoltage conditions are critical constraints Main grid divided into 5 networks, each energized independently and simultaneously Once networks restored, they are synchronized and service to load restored in increments

56 Characteristics of Generating Units Type Cap. (MW) Startup req. (MW) Ramp. Rate (MW/hr) Min Output (%) Crank to paral. (hr) Crit. max. int. (hr) BS/NBS C R k α% T1 T2 T3 Crit. min. int. (hr) t

57 Actual Generator MVAR Capability M. M. Adibi and L. H. Fink, "Overcoming restoration challenges associated with major power system disturbances - Restoration from cascading failures," Power and Energy Magazine, IEEE, vol. 4, no. 5, pp

58 Initial Sources of Power Availability of Initial Sources: Minutes Success Probability Run-of-the-River Hydro 5-10 High Pump-Storage Hydro 5-10 High Combustion Turbine (CT) in 2 or 3 CTs Full or Partial Load Rejection Short G T 50% Low Frequency Isolation Scheme Short G T 50% Controlled Islanding Short Special Cases Tie-Line with Adjacent Systems Short Not Relied On

59 Energizing High Voltage Lines Causes of overvoltage» Energizing long HV, EHV and UHV lines» Inadequate energizing sources (On-line generating units to absorb VARs?)» Inadequate underlying loads (reactive load to absorb VARs?)

60 Strategy-oriented or Objective-oriented Policies System Characteristics Constraints Strategy-oriented Objective-oriented

61 Restoration Process Preparation System Restoration Load Restoration Optimal Generator Start-up Sequence to Maximize Overall System Generation Capability Optimal Transmission Path Search and Power Flow Check to Implement the Sequence Optimal Load Pick-up Sequence to Minimize Unserved Load

62 Generic Restoration Milestones (GRMs) GRMs Synchronize Islands Restoration System Restoration Returns to Normal Operation Connect Islands Pick up Load Establish Transmission Grid Find Path to Crank Non Black Start Units Start Black Start Units Sectionalizing 62 Ascertain System Status

63 Generic Restoration Milestones (GRMs) GRM1: Form BS_Non_BS Building Blocks GRM2: Build Electrical Island GRM3: Synchronize Electrical Islands GRM4: Establish Transmission Path GRM5: Serve Load in Area GRM6: Connect with Neighboring Systems Considering the system characteristics, a specific restoration strategy can be established by combining and sequencing of GRMs 63

64 GRMs for PJM / AEP strategy GRM1: Form BS_Non_BS Building Blocks GRM2: Build Electrical Island GRM3: Synchronize Electrical Islands GRM4: Establish Transmission Path GRM5: Serve Load in Area GRM6: Connect with Neighboring Systems 64

65 GRMs for HQ strategy The structure of the Hydro-Quebec system is quasi-radial: two remote production sites in the northwest and east of Quebec are connected to the load in the southwest by long transmission lines GRM4: Establish Transmission Path GRM2: Build Electrical Island GRM3: Synchronize Electrical Islands GRM5: Serve Load in Area 65

66 GRMs-based Generic and Adaptive Tool

67 Core Algorithms Set 67

68 GRM1: Form Black_Start_Non _Black_Start Building Block To minimize the total duration for self-healing f (, ) min generating units S xi θs tx x fs 1( xj, θs+1) x θ i S i j

69 Finding Feasible Operating Points by OPF with Transient Stability Constraints ij min c( x) PG P ˆˆ L Re( V&. ( YV &&)) hx ( ) 0 ˆ ˆ G L Im(. ( )) Q Q V& YV && PG PG PG QG g( x) QG QG V V V Adjustment of each generating unit Power flow Limits of variables ij 0 ij ij Pi, j ij ij P i P P P P P P P new 0 i i i, j new 0 j j i, j P P new i M i P P m i m i j P M i P t new i t f P P new j m j P M i M m new Pj Pj Pj Standing angles involved in OPF Trajectory sensitivity technique 0 ij ij Pi, j ij ij P i P new 0 P i Pi Pi, j j max ij new 0 P j Pj Pi, j

70 Finding Feasible Operating Points by OPF with Transient Stability Constraints

71 Algorithms for GRM3~6 GRM3: Serve Load in Area GRM4: Synchronize Electrical Islands Finding path for synchronization Adjusting voltages and phase angles Closing breaks GRM5: Form Electrical Island Pickup loads, establish transmission path Adjusting voltages and phase angles GRM6: Connect with Neighboring System the voltage in the neighboring system cannot be adjusted

72 System Restoration Navigator The program has the following functional features: Following a complete or partial outage. Graphical user interface allows the user to enter or modify the input parameters, execution modules and view the outputs. Establish strategy automatically and interactively

73 Setting Priorities Users can set milestone and priority for each generating unit and critical loads in a table and a oneline diagram. Users can import/export characteristics of each generating unit, load, branch and transformer into *.char files. The user can save a system restoration plan in series of TXT files or image files step by step

74 Hawaiian Electric Company (HECO) Bus Generator Line Transformer Dispatchable Load Find solution within 8 min

75 Applications EPRI members:» Hawaii power grid» BPA: Northwest power grid» New England ISO IreGrid Guangdong power grid Hubei power grid

76 Today's Research for Tomorrow's Grid Methodology Functionality Renewables Implementation Restoration Customized Off-line Switch-off Operation Self-healing Generic On-line Participation Planning & Operation

77 From Off-line to On-line Tools off-line decision support on-line

78 Branch-bus Model to Breaker-based Model Branch-bus model: the order of restoration bus Breaker-based model: the breaker operation

79 Equivalent Problem in Graphic Theory The weighted graph for substation Weighting criteria: the priority operation of breakers, the constraints of breaker operation Equivalent problem: the shortest path problem, Dijkstra algorithm

80 Implementation Calculation result: the sequence of switching operations can be searched, which is

81 Implementation

82 Constructing Risk-based Restoration Strategy Following a complete or partial outage, dispatchers in the control center work with field crews to reestablish the generation and transmission systems and then to pick up load and restore service The established restoration strategies should meet the operating constraints as well as the proposed risk constraints

83 83 Risk-based Restoration The transmission lines with lower availabilities are deleted from the graph. The path with the largest availability from the energized block to the target generating unit will be found The path from the energized block to a target generating unit with minimal total charging current subject to acceptable availability will be identified.

84 84 Results The proposed method was integrated into System Restoration Navigator (SRN) developed by HKU and supported by EPRI.

85 85 Results The proposed method was integrated into System Restoration Navigator (SRN) developed by HKU and supported by EPRI.

86 Today's Research for Tomorrow's Grid Methodology Functionality Renewables Implementation Restoration Customized Off-line Switch-off Operation Self-healing Generic On-line Participation Planning & Operation

87 Renewable s s Participation Preparation System Restoration Load Restoration Optimal Generator Start-up Sequence to Maximize Overall System Generation Capability Optimal Transmission Path Search and Power Flow Check to Implement the Sequence Optimal Load Pick-up Sequence to Minimize Unserved Load

88 Enabling Renewables in Load Restoration Negative contribution of wind power in restoration» Uneven absorption of the surplus of wind generation capacity UCTE recommendation» Renewables participate in the restoration in due proportion» Renewables become part of the system security How to integrate wind power in the load restoration? ERGEG Final Report. (2007). The lessons to be learned from the large disturbance in the European power system on the 4th of November [Online]. Available: _PUBLICATIONS /CEER _PAPERS /Electricity/2007/E06-BAG _Blackout-FinalReport_ pdf

89 Reliability Requirements Various participants: independent system operator (ISO), transmission owner (TO), distribution owner (DO), generation owner (GO) Restoration control should be coordinated for reliability (NERC, UCTE) Industry practice suggestion» Coordinate the sizing and location for load pickup (PJM)» DO picks up loads at the amount /rate specified by ISO/TO (IESO)» Wait for voltage and frequency to stabilize before picking up the next block of load (IESO)

90 Multi-stage MINLP-based Methodology Identify available generation & transmission resources at each stage C i ac i i R i t P.i k i Formulate a MINLP model for coordinated load pickup at each stage Estimate the duration of each stage by calculating the ramping time

91 Multi-stage MINLP-based methodology Model structure s.t. min up,, Q, V& G G [ k ][ P ] u P coldload T i, u 0,1 i u P L CGPG CLPL real([ V& ]conj( YV& )) Cunserved[ PL] u 0 CQ G G CQ L L imag([ V& ]conj( YV& )) Cunserved[ QL] u 0 PG PG PG QG QG QG V V& V L NLP part L.max MILP part MINLP! But on the bright side, separate NLP part and MILP part Zhijun Qin, Yunhe Hou, Chen-ching Liu, Shanshan Liu, Wei Sun, Coordinating Generation and load pickup during load restoration with discrete load increment and reserve constraints, submitted to IEEE trans. On Power System for review.

92 Multi-stage MINLP-based Methodology Branch-and-bound fails even for tiny cases! Solution algorithm (Branch-and-cut)» Problem-specific branching method» Gomory rounding cut, Knapsack cut, pre-solve Solution Strategy No cuts + maximum fractional branching No cuts + Pseudo-cost branching Gomory rounding cut, knapsack cover cut + Pseudo-cost branching Fixing variable cut + problem-specific branching Number of Nodes in B&C tree 5,897 4,

93 Multi-stage MINLP-based Methodology Case study

94 Enabling Renewables in Load Restoration Manage the generation portfolio» Mindful of the variability and uncertainty of wind energy» Match load pickup amount with generation capability (subject to transmission constraints)» Timing to re-connect wind power plants: adequate reserve level» Guard against loss of wind energy contingency with spinning reserve» Perform frequency control with responsive reserve Variability Loss of wind energy contingency Erigrid data(11/05/2014)

95 Enabling Renewables in Load Restoration Model extension with reserve constraints» Spinning reserve P [ P, P ] m wind i wind i wind i G» Responsive reserve P P R, i m m m wind i Gj j j windg m j P [ P, P ], i K m m wind i wind i wind i windg C m j j j K C P, m m j j Gj, max{ P P, P P } K» Transmission constraints: DC power flow m m m wind i wind i wind i wind i j j Spinning reserve of conventional generating units Responsive reserve of conventional generating units m G

96 Enabling Renewables in Load Restoration Two-stage robust load restoration model» Decision-making mechanism 1 st -stage decision: x [ s1; s2;...; sn ; u1; u2;...; u ] P N G PL robust, all possible future scenario considered 2 nd -stage decision: y [ PG1; PG2;...; PGN] wait-and-see recourse, always exists feasible y Uncertainty construction: deterministic set with budget m wind i correlation can be included n m wind i m» Model formulation 1 P T T min c x max min b y x w U y ( x, w) st.. Fx f, x binary ( xw, ) { y: Gx Ey Mw h} w [ P P ; P ;...; P ] U m m m m wind 1 wind i wind 2 wind n m wind i m U : { w: P [ P, Pwind i ], i 1,.., n P ( Pwind i P )/2 i wind i m wind i m m wind i ( P )/2 }

97 Enabling Renewables in Load Restoration Re-connect wind farm Wind farm Load restoration duration drops from 379 mins. to 333 mins.

98 Today's Research for Tomorrow's Grid Methodology Functionality Renewables Implementation Restoration Customized Off-line Switch-off Operation Self-healing Generic On-line Participation Planning & Operation

99 Black-start Resources Planning BS units installed on different buses (locations) significantly change the self-healing capability. The problem is: it is possible to change locations of BS units

100 FCB Units in Post-separation separation Controls

101 VSC-HVDC Black Start Black start study in a system with VSC-HVDC Restoration sequence : 1. Deblock VSC1: ac voltage of the VSC1 ramped up to the rated voltage 2. Close the ac breaker B1 and switch on the no-load line 3. Switch on the transformer T1 and T3 respectively 4. T3 is energized and the auxiliary equipment of G1 will be switched on 5. G1 will be synchronized and connected to the grid after reaching the synchronous speed

102 Today's Research for Tomorrow's Grid Today's Research Tomorrow's Grid

103 Today's Research for Tomorrow's Grid Today's Research Tomorrow's Grid Self-healing Smart Grid

104 Relevant research activities NSFC RGC Guangdong Power Grid Generic Methodology Renewables participation (RGC/GRF712410) Restoration with operating risk (RGC/GRF712411) Restoration with dynamic and EMTP constraints ( ) Strategic Defense System: Vulnerability Mitigation & Outage Restoration (RGC/ECS739713) Restoration with Fast-cut-back units Generic Methodology (GRMs) EPRI Implementation framework (bi-level) Algorithms -> multi-island -> operating point identification -> transit stability Potential applications of new technology SRN V1.0 HVDC PMU EMTP Blackstart capacity optimization Dynamic (TDS) for restoration SRN V2.0 SRN V2.0 Breakerbased model Tech. Transfer Award, EPRI SRN & OTS Operators Training Courses for EPRI Members

105 References 1. S. Liu, Y. Hou, C. Liu, and R. Podmore, "The Healing Touch: Tools and Challenges for Smart Grid Restoration," Power and Energy Magazine, IEEE, vol. 12, pp , Y. Hou, C.-C. Liu, K. Sun, P. Zhang, S. Liu, and D. Mizumura, "Computation of Milestones for Decision Support During System Restoration," Power Systems, IEEE Transactions on, vol. 26, pp , C. C. Liu, W. Sun, Y. Hou, and S. Liu, "Putting into Practice the Dream of a Self-healing Smart Grid," IEEE Smart Grid Newsletter, September C. Peng, Y. Hou, C. Wang, and Z. Qin, "Constructing Breaker Sequence based System Restoration Strategy with Graph Theory," in Power and Energy Society General Meeting (PES), 2014 IEEE, Z. Qin and Y. Hou, "A Branch-and-cut Method for Computing Optimal Load Restoration Strategy Considering Transmission Network and Discrete Load Incremant " presented at the 18th Power system Computation Conference, Wroclaw, Poland, Y. Hou, Z. Qin, and J. Yan, "Constructing Restoration Strategies with Availability Risk Constraints," in Power and Energy Society General Meeting (PES), 2014 IEEE, L. En, W. Ning, Q. Zhijun, L. Haoming, and H. Yunhe, "Black-start strategy for power grids including fast cut thermal power units," in Power and Energy Society General Meeting (PES), 2013 IEEE, 2013, pp Y. Hou, S. Liu, and Z. Qin, "Construction of System Restoration Strategy with PMU Measurements," Energy Procedia, vol. 12, pp , Z. Qin, S. Liu, and Y. Hou, "Virtual Synchroscope: a novel application of PMU for system restoration," in Advanced Power System Automation and Protection (APAP), 2011 International Conference on, 2011, pp S. Liu, R. Podmore, and Y. Hou, "System Restoration Navigator: A decision support tool for System Restoration," in Power and Energy Society General Meeting, 2012 IEEE, H. Liu, X. Chen, K. Yu, and Y. Hou, "The Control and Analysis of Self-Healing Urban Power Grid," Smart Grid, IEEE Transactions on, vol. 3, pp , 2012.

106 Questions