Solar Storm Probabilities Grid Contingencies Harmonic Relay Settings

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1 Presentation to NERC GMD Meeting March 18 th 19 th, 2014 SolidGround TM Transformer Neutral Blocking System Solar Storm Probabilities Grid Contingencies Harmonic Relay Settings

2 Agenda US Power Usage and the One in 100 Year Storm When will next Extreme Storm Hit? New Contingency Modeling Results for the ATC Power Grid Potential Damage to Generator Rotors by GIC produced Harmonics and Harmonic Relay Settings Solid Ground Installation status in the Wisconsin ATC Grid

3 Total US Energy Usage (Billions of Kilo Watt Hours) [1] From J. Kappenman, Great Geomagnetic Storms., Adv. In Space Research 38, (2006), p Rate of Change of Magnetic Field (nt/min) US Electrical Power Usage & GMD Events 5,000 4,500 4,000 3,500 3, ,800 nt/min Carrington Storm [1] ,800 nt/min NY Railroad Storm [1] 6,000 5,000 4,000 2,500 3,000 2,000 1,500 1, Quebec ~ 500 nt/min ~ 2 V/km 2003 Storm 0 ~ 1 V/km Years 2,000 1,000

4 Geo-Electric Fields for a Severe Solar Strom a) British Col. b) Quebec Statistics of Geo-Electric Fields calculated from Geomagnetic recordings from 1993 through 2006 Geo-Electric Field 20 V/km, range 10 to 50 V/km [2] [2] From A. Pulkkinen et.al. are from Space Weather publication in 2012

5 Geomagnetic Latitude is much different than Geographic Latitude Northern FL at 40 deg Magnetic Lat. GMD records show impact of weak storms (Aug 14, 2003) cover nearly all of North America (40 deg & greater magnetic latitude) [1] [1] Taken from A. Pulkkinen et.al. are from Space Weather publication in 2012

6 Probability of a Carrington Extreme Solar Storm Hitting the Earth The probability of time events that are continuous and independent of each other (i.e. a Poisson process) is given by an Exponential distribution Cum Probability is given by P(t) = 1 exp (-lt) where t is the time of occurrence of an event and l a single parameter fit to the data Four papers published in 2012 & 2013 address this question The authors used various long term solar storm recorded data sources The reported results are in remarkably good agreement

7 Probability of a Carrington Extreme Solar Storm Hitting the Earth The probability of time events that are continuous and independent of each other (i.e. a Poisson process) is given by an Exponential distribution; the Cum probability distribution is: P(t) = 1 exp (-lt) where t is the time of occurrence of an event and l a single parameter fit to the data [1] [1] Ross, Sheldon M. (2009). Introduction to probability and statistics for engineers and scientists (4th ed.). Associated Press. p ISBN Several papers published in 2012 & 2013 address this question; namely, P. Riley, R. Katakoa, J. F. Love and R. Thorberg All assume the Poisson process i.e. the time occurrence of events is independent The authors used various solar storm recorded data sources: P. Riley 45 yrs of NASA magnetic data and 10 yrs of CME speed data R. Katakoa 89 yrs of Kakioka Observatory, Japan, magnetic data J.F. Love 10 yrs of USA magnetic data R. Thorberg 60 yrs of Northern Eurpore magnetic data The results are in remarkably good agreement: But the lack of Extreme events give rise to Large Statistical Uncertainties

8 Probability a Carrington Storm (4,800 nt/min) will hit within 10, 20, 30 & 40 Years (data fit to Poisson Distribution) Published Predictions Predicted Probability (%) Within 10 Yrs Probability (%) Within 20 Yrs (Poisson Dist.) Probability (%) Within 30 Yrs (Poisson Dist.) Probability (%) Within 40 Yrs (Poisson Dist.) P. Riley [1] R. Katakoa [2] R. Thorberg [3] * J. F. Love [4] Weak Solar Cycles R. Katakoa [2] Weak Solar Cycles Riley, P. (2012), On the probability of occurrence of extreme space weather events, SpaceWeather, 10, S02012, doi: /2011sw Kataoka, R. (2013), Probability of occurrence of extreme magnetic storms, Space Weather, 11, doi: /swe Thorberg R., Division of Industrial Electrical Engineering and Automation Faculty of Engineering, LTH, Lund University ): Risk analysis of geomagnetically induced currents in power systems * Note Thorberg provided probability for event within 3 years (4.7%) which as been extended to the probability for a 10 year event. 4. Love, J. F. (2012), Credible occurrence probabilities for extreme geophysical events: Earthquakes, volcanic eruptions, magnetic storms, Geophys. Res. Lett., 39, L10301, doi: /2012gl

9 Cum Probability of an Extreme GMD Event (%) Cum Probability of an Extreme (Carrington) GMD Hitting the Earth versus Future Years 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Thorberg Kataoka I Riley Love Kataoka II l =0.016 l = l =0.013 l = Years Projections Based on Long Term Solar Data Projections Based on Weak Solar Cycle 50 % Prob. at ~ 50 Years Three Independent Studies Give Similar Predictions for the Probability of a Carrington Extreme Storm

10 Cum Probability of an Extreme GMD Event (%) Cum Probability of an Extreme (Carrington) GMD Hitting the Earth versus Future Years 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Thorberg Kataoka I Riley Love Kataoka II l =0.016 l = l =0.013 l = Error Bars from Love s Analysis Years Projections Based on Long Term Solar Data Projections Based on Weak Solar Cycle 50 % Prob. at ~ 50 Years Three Independent Studies Give Similar Predictions for the Probability of a Carrington Extreme Storm

11 Chester Maine GIC Storm Data Linear Projection to 100 Year Storm (5,000 nt/min) gives neutral current of: Minimum = 500 Amps Mean = 1,000 Amps Max = 2,000 Amps 250 nt/min Data taken from EIS submission to Maine PUC, Oct 4, 2013 ~ 100 Amperes

12 IEEE THD Voltage Standard 5% Potential for Upset and/or Damage to Customer Equipment

13 ATC Modeling Results of Voltage Collapse for three Conditions Operating System Conditions for ATC Power Grid Collapse Voltage (V/km) Peak Power, No Contingencies 22.0 Shoulder Load, No Contingencies 23.0 Shoulder Load w Medium Transfers, No Contingencies 20.5 Shoulder Load w High Transfers, No Contingencies 17.5 Power Grid Collapse Voltages were Calculated using PowerWorld LLC Modeling Software

14 Generation Impacts Rotor Heating Effects from GIC Conclusion by Gish et. al. Damage to a generator rotor is possible from GIC The primary cause of heating is negative sequence second harmonic and positive sequence fourth harmonic adding together on the rotor. Conventional negative-sequence overcurrent relays equipped with a sensitive alarm may provide satisfactory protection the trip may be adjusted to a per unit setting slightly above the standard limit with a 120 second timer. IEEE Transaction on Power Delivery, April 1994 Authors: Gish, Feero and Rockefeller

15 Generation Impacts Rotor Heating Effects from GIC Discussion by R. A. Walling: This paper describes a potentially grave consequences of GIC that is under appreciated by the industry. Although GIC-related damage of generators has not been documented, our analyses lead us to concur with authors that stator current harmonics during severe GMD can lead to rotor heating duty more severe than caused by operating at the maximum fundamental frequency negative sequence imbalance as defined by ANSI C IEEE Transaction on Power Delivery, April 1994 Authors: Gish, Feero and Rockefeller Commenter on the paper: R. A. Walling

16 Generation Impacts Generator Thermal Stress during a GMD Conclusions by Rezaei-Zare & L. Marti this study indicates that the relevant IEEE standards C50.12 and C50.13 require modifications to take into account the even harmonics of the generator current during a GMD event.. The standards underestimate the effective negative sequence current which contributes to the rotor heating. PESGM Authors: Rezaei-Zare and Luis Marti, IEEE PES, July 2013, Vancouver, Canada The simulation results reveal that the generator capability limit can be exceeded at moderate GIC levels, e.g. 50A/phase, and the rotor damage is likely during a severe GMD event.

17 Hobson s Choice Hobson s Choice to the industry: Let relays trip out generators Or Do nothing and chance damage to generators

18 ATC (Wisconsin) Grid Map Weston High Transfer Increase flow to ~ 95% of interface limit 2,600 MW of Generation shift

19 ATC Modeling Results of Voltage Collapse for Contingency Conditions Operating System Conditions for ATC Power Grid Collapse Voltage (V/km) Peak Power, No Contingencies 22.0 Shoulder Load w High Transfers, No Contingencies Loss of Largest Generator at One Site, High Transfers Loss of Largest Two Generators at One Site, High Transfers Loss of All Generation at One Site, High Transfers Power Grid Collapse Voltages were Calculated using PowerWorld LLC Modeling Software

20 ATC Modeling Results of Voltage Collapse for Contingency Conditions Operating System Conditions for ATC Power Grid Collapse Voltage (V/km) Period of Storm from Pulkkinen et. al. Statistics Peak Power, No Contingencies 22.0 ~ 100 Year Shoulder Load w High Transfers, No Contingencies Loss of Largest Generator at One Site, High Transfers 17.5 ~ 40 Year 16.6 ~ 30 Year Loss of Largest Two Generators at One Site, High Transfers Loss of All Generation at One Site, High Transfers 14.5 ~ 20 Year 12.4 ~ 10 Year Period of Storms were derived from A. Pulkkinen et.al. Storm Statistics from Space Weather publication in 2012

21 ATC Modeling Results of Voltage Collapse for Contingency Conditions Operating System Conditions for ATC Power Grid Collapse Voltage (V/km) Period of Storm from Pulkkinen et. al. Statistics Collapse Voltage after Blocking in 25 Substations Peak Power, No Contingencies 22.0 ~ 100 Year 31 Shoulder Load w High Transfers, No Contingencies Loss of Largest Generator at One Site, High Transfers 17.5 ~ 40 Year ~ 30 Year 25 Loss of Largest Two Generators at One Site, High Transfers Loss of All Generation at One Site, High Transfers 14.5 ~ 20 Year ~ 10 Year 18 Period of Storms were derived from A. Pulkkinen et.al. Storm Statistics from Space Weather publication in 2012

22 Voltage at Lowest pu Voltage Bus ATC Grid Voltage Collapse vs GMD Fields and Neutral Blocking Systems Voltage Performance, 60 degree storm, Summer Peak, No Transfers, No Contingencies Grid Collapse 22 V/ km Improvement with Neutral Blocking 30 V/ km Severe GMD Year Storm Prediction (20 V/km, range 10 to 50 V/km) [1] Base 5 Subs 10 Subs 15 Subs 20 Subs 25 Subs Field Strength (V/km) Neutral Blocking Significantly Improves Grid Voltage Collapse

23 Voltage at Lowest pu Voltage Bus ATC Grid Voltage Collapse vs GMD Fields and Neutral Blocking Systems Voltage Performance, 60 degrees Storm, Summer Shoulder with High Transfer, Weston Generation Outage Grid Collapse at 12 V/ km (10 Yr Event) Improvement with Neutral Blocking to 18 V/ km GMD 100 Year Storm Prediction (20 V/km, range 10 to 50 V/km) [1] Base 5 Subs 10 Subs 15 Subs 20 Subs 25 Subs Field Strength (V/km) Neutral Blocking Significantly Improves Grid Voltage Collapse

ATC SolidGround TM System Installation American Transmission Company, WI ATC has installed a SolidGround TM (SG-22) system at their Morgan sub-station in

24 ATC SolidGround TM System Installation American Transmission Company, WI ATC has installed a SolidGround TM (SG-22) system at their Morgan sub-station in northern Wisconsin Reports will be shared with the appropriate NERC committees, EPRI and the power industry SEL Control Electronics Tested with SolidGround

25 First Wisconsin Installation SolidGround

26 GIC Simulation Tools Luis Marti Hydro One Networks Ontario, Canada

27 Focus of this presentation Geomagnetic Field Geoelectric Field Potential Mitigation Measures B(t) Earth Conductivity Model E(t) dc System Model GIC(t) Transformer Model (Electrical) Transformer Model (Thermal) vars Power Flow Analysis Temp(t) Hot Spot Temp. Bus Voltages Line Loading & var Reserves Assessment Criteria Fail Pass Operating Procedures and Mitigation Measures (if needed)

28 Calculation of the Geoelectric field Geomagnetic Field Geoelectric Field Potential Mitigation Measures B(t) Earth Conductivity Model E(t) dc System Model GIC(t) Transformer Model (Electrical) vars Power Flow Analysis Bus Voltages Line Loadi var Reser Transformer Model (Thermal) Temp(t) Hot Spot Temp. Calculation of E(t) from B(t) Data requirements Geomagnetic time series or waveshape B E (t) and B N (t) Earth conductivity model Result is the geoelectric field time series or waveshape E E (t) and E N (t)

29 Earth model

30 Geomagnetic field B(t)

31 Geoelectric field

32 Geoelectric Field Tool Extracted from Hydro One s real time GIC simulator Validated with closed-form waveshapes

33 B(t) Fmax = 10 mhz

34 E(t) Fmax = 10 mhz

35 E(t) Fmax = 10 mhz (close-up)

36 B(t) Fmax = 1 mhz

37 E(t) Fmax = 1 mhz

38 E(t) Fmax = 1 mhz (close-up)

40 Calculation of Thermal Response Geomagnetic Field Geoelectric Field Potential Mitigation Measures B(t) Earth Conductivity Model E(t) dc System Model GIC(t) Transformer Model (Electrical) Transformer Model (Thermal) vars Power Flow Analysis Temp(t) Hot Spot Temp. Bus Voltages Line Loading & var Reserves Assessment Criteria Fail Pass Operating Procedures and Mitigation Measures (if needed) Calculation of θ(t) from GIC(t) Data requirements GIC(t) for any gven transformer Thermal step response for winding and metallic hot spots for different GIC values Measured or Calculated

41 Thermal Response Tool Extracted from Hydro One s real time GIC and steady-state simulators Straightforward implementation of Marti, L., Rezaei-Zare, A., Narang, A., "Simulation of Transformer Hotspot Heating due to Geomagnetically Induced Currents," IEEE Transactions on Power Delivery,, vol.28, no.1, pp , Jan Most measured time constants seem to be in the same range so far More work on measurement-validated models are necessary for the asymptotic responses. A number of published measurements and calculations are in the same range Some manufacturers (notably Siemens and Von Roll) are working on their models so that they can reproduce measurements For now, we have very conservative models. Stay tuned.

43 Any more questions?

44 PowerWorld Simulator GIC NERC GMD Task Force March 19, South First Street Champaign, Illinois (217)

GIC calculations into PowerWorld Simulator, engineers can readily see the impact of GICs on

45 GIC Modeling Modern methods model GIC as DC voltage sources in transmission lines With pertinent parameters, GIC computation is a straightforward linear calculation By integrating GIC calculations into PowerWorld Simulator, engineers can readily see the impact of GICs on their systems and consider mitigation options PowerWorld Simulator GIC 2014 PowerWorld Corporation 2

46 GIC Analysis Inputs GIC calculations use some existing model parameters such as line resistance Some additional parameters are needed Substation geo-coordinates and grounding resistance Transformer grounding configuration, coil resistance, core type, whether auto-transformer, whether threewinding transformer Generator step-up transformer parameters Transmission operators would be in the best position to provide these values, but all can be estimated when actual values are not available PowerWorld Simulator GIC 2014 PowerWorld Corporation 3

47 GIC Analysis Outputs and Results GIC studies involve the traditional power system results (voltages, flows, etc.) and GIC-specific quantities, such as Transformer neutral amps Transformer Mvar losses Substation neutral dc voltages Bus dc voltages Transmission line dc amps Providing easy access to the data and results is a key objective in PowerWorld Simulator, as is good wide-area visualization PowerWorld Simulator GIC 2014 PowerWorld Corporation 4

48 GMD Storm Scenarios The starting point for GIC analysis is an assumed storm scenario; this is used to calculate transmission line DC input voltages Uniform surface electric field model: magnitude and direction Geospatially and time-varying electric field model Direct user input of GIC DC voltage input on each transmission line, OR External input files (*.csv) specifying a time-series geospatial grid of northward and eastward E-field magnitude PowerWorld Simulator GIC 2014 PowerWorld Corporation 5

49 Uniform Electric Field Modeling Electric-Field Magnitude (V/mile or V/km) Storm Direction (0 to 360 degrees) N 0 (south-north) (west-east) 165 PowerWorld Simulator GIC 2014 PowerWorld Corporation 6

50 Time-Varying DC Input Voltage Allows direct entry of GIC DC input voltage on each transmission line Can be initialized with uniform field assumptions, then optionally modified Calculation mode Time and Field input Click Add at Time PowerWorld Simulator GIC 2014 PowerWorld Corporation 7

51 Time and Geospatially-Varying Electric Field Read a non-uniform surface electric field specification from a set of external text (*.csv) files PowerWorld Simulator GIC 2014 PowerWorld Corporation 8

52 Geographic Information GMD-induced DC voltages depend on the storm strength and orientation and the latitude and longitude of the transmission lines The electric field is integrated along the path of the transmission line The geo-coordinates of the terminal buses are sufficient for uniform field modeling Hence buses must be mapped to substations, and substations to their geo-coordinates Substation/geographic data can be supplied by PowerWorld for FERC 715 planning models Buses mapped to substations Latitude and longitude for substations PowerWorld Simulator GIC 2014 PowerWorld Corporation 9

53 Grounding Resistance Substation grounding resistance is the resistance in ohms between the substation neutral and earth ground (zero-potential reference) An actual fall of potential test is the best way to determine this resistance Simulator provides defaults based on number of buses and highest nominal kv, but research has shown this to be a poor substitute for actual measurements Simulator defaults range from 0.1 to 2.0 Ω Substations with more buses and higher nominal kv are assumed to have lower grounding resistance PowerWorld Simulator GIC 2014 PowerWorld Corporation 10

54 Default Assumptions: Transformers It is always best to provide known quantities, especially for configuration and autotransformer fields If any transformer information is unknown, Simulator uses assumed values based on the power flow model Coil Resistance ohms per phase estimate based on positive-sequence AC per-unit series resistance and transformer impedance base Assumed split between each winding: RR pppp RR BBBBBBBB,HHHHHHHHHHHHHHH = RR HHHHHHHHHHHHHHH + aa tt 2 RR LLLLLLLLLLLLLL RR HHHHHHHHHHHHHHH = aa tt 2 RR LLLLLLLLLLLLLL PowerWorld Simulator GIC 2014 PowerWorld Corporation 11

55 Default Assumptions: Autotransformers Units are assumed to be autotransformers if all of the following criteria are met unit is not a phase-shifting transformer high side and low side are at different nominal voltages high side nominal voltage is at least 100 kv turns ratio is less than or equal to 3 These parameters may be adjusted at Options DC Current Calculation PowerWorld Simulator GIC 2014 PowerWorld Corporation 12

transmission and distribution side configurations may be specified

56 Default Assumptions: Transformer Configuration Unknown windings can be assumed Delta, Grounded Wye, or Ungrounded Wye Default transmission and distribution side configurations may be specified globally or by area PowerWorld Simulator GIC 2014 PowerWorld Corporation 13

57 Mapping Transformer GICs to Transformer Reactive Power Losses Transformer specific, and can vary widely with the core type: Single phase, shell, 3-legged, 5-legged Ideally this information would be supplied by the transformer owner For large system studies, default data may be used when nothing else is available. Scaling value changes with core type Simulator supports default values or a user-specified linear mapping Debate in the industry with respect to the magnitude of damage GICs would cause in transformers (from slightly age to permanently destroy) PowerWorld Simulator GIC 2014 PowerWorld Corporation 14

58 Default Assumptions: Transformer GIC Mvar Losses K-Factor relates transformer s effective GIC (I GIC ) to 3-phase reactive power loss at nominal voltage V Q = V K I Nom kv Loss pu GIC V Nom kv,assumed I GIC is per-phase effective GIC amps, computed from GIC in high and low side windings and turns ratio (a t ) I GIC = ai + I a t H L t PowerWorld Simulator GIC 2014 PowerWorld Corporation 15

59 K-Factor K-Factor may be entered directly as GIC Model Param with GIC Model Type set to Linear User-specified K-Factor Assumed K-Factor Otherwise, K-Factor is assumed based on Core Type and high-side nominal voltage Assumptions may be modified on Options AC Power Flow Model PowerWorld Simulator GIC 2014 PowerWorld Corporation 16

60 Other Modeling Assumptions Options DC Current Calculation Minimum Voltage Level to Include in Analysis (kv): transmission lines below this level are assumed to have zero GIC DC voltage input Automatic Insertion of Substations for Buses without Substations It is strongly recommended to assign all buses to substations and all substations to latitude/longitude locations, at least within the GIC study footprint Default assumption is to model unlocated facilities as ungrounded PowerWorld Simulator GIC 2014 PowerWorld Corporation 17

61 Integration of GIC Mvar Losses in Power Flow Checkbox on GIC Analysis Form Subsequent solutions of AC power flow include transformer GIC reactive power losses PowerWorld Simulator GIC 2014 PowerWorld Corporation 18

Uniform Field Example Eastern Interconnect power flow model NOTE: The examples that follow contain no specific parameters for transformers or substation

62 Uniform Field Example Eastern Interconnect power flow model NOTE: The examples that follow contain no specific parameters for transformers or substation grounding resistance; results are hypothetical and for illustration of software capabilities only PowerWorld Simulator GIC 2014 PowerWorld Corporation 19

63 Uniform Field Example: Worst-Case Storm Angle Determination Angle rotated in 5 degree increments, sorted by system-wide transformer GIC Mvar losses PowerWorld Simulator GIC 2014 PowerWorld Corporation 20

64 Increasing Field Magnitude: AC Bus Voltage Drop Contour 2 V/km 4 V/km 5 V/km 6 V/km PowerWorld Simulator GIC 2014 PowerWorld Corporation 21

65 Non-Uniform Field Example: Surface Electric Field Magnitude PowerWorld Simulator GIC 2014 PowerWorld Corporation 22

66 Non-Uniform Field Example: Transformer Totals for Entire Event Total Amp-Minutes of GIC neutral current for each transformer PowerWorld Simulator GIC 2014 PowerWorld Corporation 23

Transformer Sensitivity Analysis Transformer I effective GIC Sensitivity can identify transmission lines with greatest effect on transformer GIC current Sort transformers by I effective

67 Transformer Sensitivity Analysis Transformer I effective GIC Sensitivity can identify transmission lines with greatest effect on transformer GIC current Sort transformers by I effective Include Brighton 500/230 kv in Sensitivity Calculation Click Recalculate Sensitivities Two lines are responsible for most of the transformer GIC PowerWorld Simulator GIC 2014 PowerWorld Corporation 24

68 Substation Resistance Sensitivity Recent research has indicated that the GICs can be quite sensitive to the assumed grounding resistance; hence measured values are recommended The relative importance of a particular substation grounding resistance can be determined by comparing its value to the driving point resistance seen looking into the network at that location; these values can be computed quickly using sparse vector methods Ri R i : = R + R i TH, i PowerWorld Simulator GIC 2014 PowerWorld Corporation 25

69 Substation Resistance Sensitivity Example Relative sensitivities for substations with high neutral GIC currents PowerWorld Simulator GIC 2014 PowerWorld Corporation 26

70 Integrating GIC Calculations into Power System Planning A large GMD could substantially affect power system flows and voltages Studies allow for testing various mitigation strategies Operational (short-term) changes include redispatching generation to avoid long distance power transfers and reducing transformer loading values, and strategically opening devices to limit GIC flows Longer-term mitigation actions include the installation of GIC blocking devices on the transformer neutrals (such as capacitors) and/or increased series capacitor compensation on long transmission lines Determining relay settings when to trip the transformer PowerWorld Simulator GIC 2014 PowerWorld Corporation 27

Capacitive Neutral Blocking Sort by Transformer Neutral Current, absolute value (hold shift key, click column header) Toggle GIC Blocked for Transformer Neutral =

71 Capacitive Neutral Blocking Sort by Transformer Neutral Current, absolute value (hold shift key, click column header) Toggle GIC Blocked for Transformer Neutral = YES for Conemaugh GSUs and recalculate GIC Conemaugh GIC goes to zero, but GIC increases in other locations PowerWorld Simulator GIC 2014 PowerWorld Corporation 28

72 Planned Software Enhancements Automatic angle rotation and determination of worst-case angle for uniform fields (currently available through external automation) Incorporation of 1D models and magnetic latitude onto a nominal electric field specification (alpha and beta scalars for benchmark events) PowerWorld Simulator GIC 2014 PowerWorld Corporation 29

73 Siemens Power Technologies International PSS E GIC Module Joe Hood Krishnat Patil GMDTF Meeting 19 March 2014 Atlanta Restricted Siemens Industry, Inc All rights reserved. Answers for infrastructure and cities.

74 PSS E GIC Module GIC Module Overview PSS E Power Flow Network PSS E GIC Data GMD Storm Scenario PSS E GIC Module GIC s, Transformer Q Losses PSS E Power Flow Network with GIC Effects AC Power Flow Contingency Analysis PV/QV Analysis Dynamic Analysis Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

76 PSS E GIC Module GIC Module User Interface GMD Storm Properties Subsystem Definition Parameters For Defaults GIC Input Data File GMD Storm Properties Network Data Output Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

77 PSS E GIC Module Key Features Integrated in PSS E Interface Uses Standard PSS E Network Data (SAV or RAW files) No Sequence Data Required Additional GIC Data Required (Separate Data File) Can be added/edited using: User interface GIC Python API Excel or Text Editor Rich Reporting and Interactive Diagrams Present GIC Results on Network Maps Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

78 GIC Data Requirements Substation Data I NAME UNIT LATITUDE Substation Number Substation Name Unit for geophysical location (longitude and longitude) Data = 0 for degrees At this time, only allowed unit for longitude and longitude is degrees. Substation latitude, positive for North and negative for South LONGITUDE Substation longitude, positive for East and negative for West RG Substation grounding resistance, ohms Default = 0.1 ohm If RG<=0.0 or RG>=99.0, assumed that substation is ungrounded Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

79 GIC Data Requirements Bus Substation Data BUSNUM SUBNUM Bus Number, must be present in power flow network data Substation Number this bus belongs to, must be defined on Substation Data record Two buses connected by a transmission line must be in different substations. As an exception, if branch buses are in same substation, specify first character of that branch circuit identifier as greater than sign ( > ). Two buses connected by a two winding transformer must be in same substation. Three buses connected by a three winding transformer must be in same substation. Two buses connected by zero impedance line must have same substation number. Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

80 GIC Data Requirements Transformer Data I J K CKT WRI WRJ WRK GICBDI GICBDJ GICBDK VECGRP CORE Winding Bus Number I Winding Bus Number J Winding Bus Number K, = 0 for two winding transformers Transformer Circuit Id DC Resistance of winding connected to Bus I, ohms/phase DC Resistance of winding connected to Bus J, ohms/phase DC Resistance of winding connected to Bus K, ohms/phase Flag for GIC blocking device present in Neutral of winding connected to Bus I, =0, no GIC blocking device, default, =1, GIC blocking device present For an auto-transformers, if either GICBDI=1 or GICBDJ=1, that auto- transformer is treated as it has GIC blocking device present. Flag for GIC blocking device present in grounding connection of winding connected to Bus J Flag for GIC blocking device present in grounding connection of winding connected to Bus K Transformer vector group Number of cores, default = 0 for Unknown =-1 for Three Phase, shell form, =1 for Single Phase, =3 for Three Phase, 3-legged, core form =5 for Three Phase, 5-legged, core form KFACTOR Factor to calculate transformer MVAR losses (MVAR/AMP), default = 0.0 Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

81 GIC Data Requirements Bus Shunt Data I ID R Fixed Shunt Bus Number Fixed Shunt Id DC resistance (Ohms/phase) Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

96 GIC Module Utility Network Study 9,500 MW summer peaking utility 7,500 miles of line (12,070 km) Voltages: 69, 115, 161, 230, 345 & 500kV System spread over 5 states Rural and metropolitan (3.7 Million population) loads Two subsystems smaller and wider study area Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

97 GIC Module Conclusion Available with current version of PSS E (33.5) Fully integrated into PSS E Any analysis available in PSS E (Contingency, PV/QV, Transient Stability) can be performed with GIC effects Results available in text reports, single line diagrams, geospatial diagrams, and object model (Python) Calculations, results post-processing, and workflow integration can be fully automated using the Python API Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

98 GIC Module Future Work Field Scaling Support Better Transformer VAR Loss Modeling Non-uniform Field Support Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

99 Contact Information Joe Hood Product Manager PSS E Siemens PTI 400 State Street Schenectady, NY Phone: +1 (803) joseph.hood@siemens.com Krishnat Patil Staff Software Engineer Siemens PTI 400 State Street Schenectady, NY Phone: +1 (518) krishnat.patil@siemens.com Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

100 Siemens Power Technologies International PSS E GIC Module Joe Hood Krishnat Patil GMDTF Meeting 19 March 2014 Atlanta Restricted Siemens Industry, Inc All rights reserved. Answers for infrastructure and cities.

101 PSS E GIC Module GIC Module Overview PSS E Power Flow Network PSS E GIC Data GMD Storm Scenario PSS E GIC Module GIC s, Transformer Q Losses PSS E Power Flow Network with GIC Effects AC Power Flow Contingency Analysis PV/QV Analysis Dynamic Analysis Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

Storm Properties Network Data Output Restricted Siemens Industry, Inc.

103 PSS E GIC Module GIC Module User Interface GMD Storm Properties Subsystem Definition Parameters For Defaults GIC Input Data File GMD Storm Properties Network Data Output Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

104 PSS E GIC Module Key Features Integrated in PSS E Interface Uses Standard PSS E Network Data (SAV or RAW files) No Sequence Data Required Additional GIC Data Required (Separate Data File) Can be added/edited using: User interface GIC Python API Excel or Text Editor Rich Reporting and Interactive Diagrams Present GIC Results on Network Maps Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

105 GIC Data Requirements Substation Data I NAME UNIT LATITUDE Substation Number Substation Name Unit for geophysical location (longitude and longitude) Data = 0 for degrees At this time, only allowed unit for longitude and longitude is degrees. Substation latitude, positive for North and negative for South LONGITUDE Substation longitude, positive for East and negative for West RG Substation grounding resistance, ohms Default = 0.1 ohm If RG<=0.0 or RG>=99.0, assumed that substation is ungrounded Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

106 GIC Data Requirements Bus Substation Data BUSNUM SUBNUM Bus Number, must be present in power flow network data Substation Number this bus belongs to, must be defined on Substation Data record Two buses connected by a transmission line must be in different substations. As an exception, if branch buses are in same substation, specify first character of that branch circuit identifier as greater than sign ( > ). Two buses connected by a two winding transformer must be in same substation. Three buses connected by a three winding transformer must be in same substation. Two buses connected by zero impedance line must have same substation number. Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

107 GIC Data Requirements Transformer Data I J K CKT WRI WRJ WRK GICBDI GICBDJ GICBDK VECGRP CORE Winding Bus Number I Winding Bus Number J Winding Bus Number K, = 0 for two winding transformers Transformer Circuit Id DC Resistance of winding connected to Bus I, ohms/phase DC Resistance of winding connected to Bus J, ohms/phase DC Resistance of winding connected to Bus K, ohms/phase Flag for GIC blocking device present in Neutral of winding connected to Bus I, =0, no GIC blocking device, default, =1, GIC blocking device present For an auto-transformers, if either GICBDI=1 or GICBDJ=1, that auto- transformer is treated as it has GIC blocking device present. Flag for GIC blocking device present in grounding connection of winding connected to Bus J Flag for GIC blocking device present in grounding connection of winding connected to Bus K Transformer vector group Number of cores, default = 0 for Unknown =-1 for Three Phase, shell form, =1 for Single Phase, =3 for Three Phase, 3-legged, core form =5 for Three Phase, 5-legged, core form KFACTOR Factor to calculate transformer MVAR losses (MVAR/AMP), default = 0.0 Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

108 GIC Data Requirements Bus Shunt Data I ID R Fixed Shunt Bus Number Fixed Shunt Id DC resistance (Ohms/phase) Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

Building GIC Data in Excel Substation and Bus Data Restricted Siemens Industry, Inc.

Building GIC Data in Excel Transformer Data Restricted Siemens Industry, Inc.

Building GIC Data in Excel Bus Shunt Data Restricted Siemens Industry, Inc.

Transformer Reactive Power Loss Modeling GIC to MVAR Scaling Factors Restricted Siemens

GIC Module Results Text Reports Restricted Siemens Industry, Inc.

GIC Module Results MVAR Losses vs. Storm Direction Restricted Siemens Industry, Inc.

Contingency Analysis with GMD Effect of GMD Strength Restricted Siemens Industry, Inc.

123 GIC Module Utility Network Study 9,500 MW summer peaking utility 7,500 miles of line (12,070 km) Voltages: 69, 115, 161, 230, 345 & 500kV System spread over 5 states Rural and metropolitan (3.7 Million population) loads Two subsystems smaller and wider study area Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

124 GIC Module Conclusion Available with current version of PSS E (33.5) Fully integrated into PSS E Any analysis available in PSS E (Contingency, PV/QV, Transient Stability) can be performed with GIC effects Results available in text reports, single line diagrams, geospatial diagrams, and object model (Python) Calculations, results post-processing, and workflow integration can be fully automated using the Python API Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

125 GIC Module Future Work Field Scaling Support Better Transformer VAR Loss Modeling Non-uniform Field Support Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

Contact Information Joe Hood Product Manager PSS E Siemens PTI 400 State Street Schenectady, NY 12305 Phone: +1 (803) 399-0563 Email: joseph.hood@siemens.

126 Contact Information Joe Hood Product Manager PSS E Siemens PTI 400 State Street Schenectady, NY Phone: +1 (803) joseph.hood@siemens.com Krishnat Patil Staff Software Engineer Siemens PTI 400 State Street Schenectady, NY Phone: +1 (518) krishnat.patil@siemens.com Restricted Siemens Industry, Inc All rights reserved. Page Siemens Power Technologies International

127 Space Weather Update Bill Murtagh Chris Balch NOAA Space Weather Prediction Center Boulder, Colorado NERC Task Force 19 March 2014

128 Solar Cycle 24 Sunspot Maximum?? 2

129 The North/South Divide The two hemispheres generally peak at different times Cycle 24 is no different N S

130 Number of occurrences of G3-level geomagnetic storms over solar cycle Geomagnetic storms occur at any time during the solar cycle and are not centered around solar maximum.

131 SWPC product distribution WECC Reliability Coordinator, Vancouver Midwest ISO, St. Paul WECC Loveland, CO NYISO SWPC G2 Alerts and Warnings

132 Proposed procedure Disseminate to RCs through NERC Hotline - ORS approved - Update NERC Advisory NOTE: Many individual power grid customers sign up for SWPC products 6

at L1 Collaborating with NASA and DOD for

ride opportunities DSCOVR Sunjammer (Solar

viability and value of solar sail technology

133 DSCOVR New Satellite Satellite News Observations Will provide critical warnings at L1 Collaborating with NASA and DOD for 2015 launch Operational Coronagraph NOAA funding studies for Compact Coronagraph (CCOR) development NOAA looking for free ride opportunities DSCOVR Sunjammer (Solar Sail Technology) NASA mission to prove the viability and value of solar sail technology (launch ~2015) Solar wind instruments provided by UCL and Imperial College

134 Continuity in Modeling at NOAA A Sun to Earth Framework Solar /Solar Wind Magnetosphere/ Ionosphere Ionosphere/ Atmosphere Earth s surface

135 Geoelectric Fields: Drivers, Geology, Normalization Christopher Balch NOAA/SWPC NERC GMDTF meeting March 2014 Atlanta, GA Outline Where we were last time Drivers versus Response functions Normalizing out the response Plans for the future

Previously Stated Objective (Ideally): Joint NOAA-USGS operational product to calculate local geoelectric field Use USGS real-time magnetometer data as the input observations Interpolate

136 Previously Stated Objective (Ideally): Joint NOAA-USGS operational product to calculate local geoelectric field Use USGS real-time magnetometer data as the input observations Interpolate geomagnetic field variation on a grid between observatories Calculate Electric field locally using regional 1D conductivity models User could view calculated E-field time series at any grid point on the map

137 Updated Perspective E-Field Calculation requires specification of two key components The External Driver (Space Weather) The Geological Conductivity Structure Significantly modifies the impact of the external driver

138 What about that Conductivity Model? Good News: Once you figure it out, it won t change (on a time scale that we care about) Bad News: It is very complex, inhomogeneous, highly structured, and not always well known Advice of our partners at USGS: 1D models for the physiographic regions are probably not sufficiently accurate Examples of three stations in Japan with similar B- field input and much different E-field (measured) (J Love paper in review)

139 Normalized E-field: Uniform Half Space Uniform half-space solution can be used to normalize the geology Succinctly characterizes the external driver E-field As specific conductivity models improve, the normalized E-field can be modified fairly easily to incorporate this information Conversion from normalized E-field to the 1D multilayer E-field is a simple multiplication (by a function of frequency will show this)

140 Uniform half-space Conductivity σσ cc, resistivity ρ cc = 1/σσ cc Time dependence ee iiωωtt Plane wave solution in conducting medium: EE xx = E o ee kk c zz, where kk cc = iiωωωωωω cc Faraday s law: EE = BB = μμ HH Polarized Plane wave kk cc E x = iiωωωωhh yy Hence the electric field is related to the magnetic field by E x = iiωωωω HH kk yy cc But using the form for kk cc, above we find E x = iiωωωωρρ cc HH yy

141 Uniform Half Space (cont) We can also write as: EE xx = ωωωω cc μμ 1 2 ee iiππ/4 BB yy ωω 1/2 shows the dependence of the driver All other things being equal, the higher frequency components get an extra kick passing from B to E A normalized value of ρρ cc = 1 ohm-m can be used to compare the input driver uniformly over the entire continent

142 Comparison with multi-layer solution n layers (i=0,1,2,.,n-1) Conductivities σσ ii, depths h i kk ii = iiωωωωωω ii For each layer: EE xx = Aiee kk zz i + B i ee kk zz i H yy = kk ii iiμμμμ A iee kk zz i B i ee kk zz i Define impedance Z i as ratio of E x /H y at z=h i Derive a recurrence relationship between Z i and Z i+1 General form: ZZ ii = iiωωωω kk ii+1 1 αα ii αα ii+1

143 Multi-layer solution (cont) In this expression, αα ii is a function of the impedance of layer i, frequency ωω, wave number kk i, and the layer thickness: h ii+1 h ii (The bottom layer is taken as infinite half space, leading to αα NN 1 = 0) Using the form for kk ii in the first layer (where ii = 0), we get surface impedance: ZZ ss = iiωωωωρρ 0 1 αα αα 0 A comparison with the uniform half space solution shows E x = ρρ 0 ρρ cc 1 αα αα 0 EE xx haaaaaaaaaaaaaaaa A comparison of the impedances for uniform half space versus multi-layer solutions can help sort out the relative role of the driver versus the geology

144 Impedance: half space vs layers - OTT

145 Impedance/ω 1/2 - OTT

146 Multi-layer correction factor - OTT

147 Impedance: half space vs layers CP1

148 Impedance/ω 1/2 CP1

149 Multi-layer correction factor CP1

150 The way forward Working jointly with NOAA, USGS and NRCAN for new operational product development Validation of the 1D E-field values is in process (CCMC leading the comparisons) Priority and focus right now is to derive B(r,t) on a spatial grid using existing network (with flexibility for addition of more stations in the future) We are now considering calculating a generic normalized E(r,t) on a spatial grid (uniform half space) with access to the correction factors if users want to use the 1D profiles

151 Additional issue We note the user requirement for to 1.0 Hz Current infrastructure is designed around 1- minute averages of the magnetometer measurements can only resolve up to Hz To resolve 1 Hz will require cadence of 0.5 s (a big change) Need to understand how significant the missing frequency bands are and importance of pushing to upgrade the infrastructure Are there empirical proxies that could adequately fill the gap?

152 Questions?

U.S. DEPARTMENT OF ENERGY DOE GMD Project Update: Sunburst, Variometers, and Beyond March 19, 2014 NERC GMD Task Force Meeting Atlanta GA John Ostrich Program Manager, GMD/EMP Activities

153 U.S. DEPARTMENT OF ENERGY DOE GMD Project Update: Sunburst, Variometers, and Beyond March 19, 2014 NERC GMD Task Force Meeting Atlanta GA John Ostrich Program Manager, GMD/EMP Activities Infrastructure Security and Energy Restoration Division Office of Electricity Delivery and Energy Reliability U.S. Department of Energy DOE/OE International Efforts on GMD September 2013

154 DOE s Interest in Sunburst and Variometer Data Utilization of Variometer Data to Enhance GMD Model Validation Effectiveness 1 Why Does DOE Care? 2 DOE Interest in High Voltage Transformers 3 Which of the Most Critical High Voltage Transformers are Most Susceptible to GMD? 4 Measurement of GICs 5 Measurement of Magnetic Fields 6 Benefits of GIC and Magnetic Field Data 7 Plan to Collect and Integrate Variometer Data 2 DOE/OE International Efforts on GMD September 2013

One Result of was Formation of the NERC GMD Task Force. Another Result was Resolve at DOE to Fund Some Efforts to Better Understand the Problem.

155 Why Does DOE Care? NERC and DOE held Workshop in 2009 to Examine Three Main High Impact Low Frequency Events to the Bulk Electric System. GMD (natural threat) and EMP (man made) were considered one of the three threats. Conclusions of this Workshop and of Studies Agreed that the Consequences Could be High and impacts Long Term. One Result of was Formation of the NERC GMD Task Force. Another Result was Resolve at DOE to Fund Some Efforts to Better Understand the Problem. High-Impact, Low-Frequency Event Risk to the North American Bulk Power System A Jointly-Commissioned Summary Report of the North American Electric Reliability Corporation and the U.S. Department of Energy s November 2009 Workshop DOE and NERC, June DOE/OE International Efforts on GMD September 2013

156 DOE Interest in High Voltage Transformers In June 2012, OE completed a study, Large Power Transformers and the U.S. Electric Grid. Study addressed U.S. electric power industry s concern about large power transformers (LPTs): Demand for LPTs is on the rise globally and domestically. LPTs require a long lead time, and transporting them can be challenging. Study is available at: 20Power%20Transformer%20Study%20 -%20June%202012_0.pdf The limited availability of [spare] extra-high-voltage transformers in crisis situations presents potential supply chain vulnerability. - A Framework for Establishing Critical Infrastructure Resilience Goals, National Infrastructure Advisory Council, DOE/OE International Efforts on GMD September 2013

157 Which of the Most Critical High Voltage Transformers are Most Susceptible to GMD? This Can be Estimated, Based on Known Information and Modeling. Depends on Location. Closer to Poles Closer to Large Bodies of Water Depends on Soil. Depends on Magnetic Fields. Depends on Type of Transformer. Depends on Age of Transformer. And Other Factors as Well. 5 DOE/OE International Efforts on GMD September 2013

Geomagnetic Disturbances. IEEE PES Chicago Chapter Technical Presentation March 12, Alan Engelmann Transmission Planning ComEd.

Geomagnetic Disturbances. IEEE PES Chicago Chapter Technical Presentation March 12, Alan Engelmann Transmission Planning ComEd. Geomagnetic Disturbances IEEE PES Chicago Chapter Technical Presentation March 12, 2014 Alan Engelmann Transmission Planning ComEd GMD Background Solar Disturbances Impacts Monitoring Events 2 Solar Disturbances