available transfer capability - oasis.oati.com terms • afc – available flowgate capability •...

Training on

Duke Energy Carolinas’ ATC

Process

Available Transfer Capability

May 24th, 2012

Agenda – High Level

• Basic Terms

• ATC Methodology

• Discussion of ATC Process

– Examples

• Wrap up

2

Basic Terms

• AFC – Available Flowgate Capability

• ATC – Available Transfer Capability

• RCPC – Remaining Contract Path Capability

• TDF – Transmission Distribution Factor

• Flowgate – A monitored pair or single element, such as a

line, or transformer, that is identified to be a potential limit.

3

ATC Methodology

• Duke Energy Carolinas uses the Flowgate Methodology

– Converted in March 2011

– Driven by significant changes in the NERC MOD standards

• Also honors tie line capability with adjacent Balancing

Authorities (BAs)

– Flowgate Methodology limited to the remaining capability of

facilities interconnecting Duke Energy Carolinas to it’s neighbors

4

ATC Calculation

ATC = Minimum

• Flowgate Methodology & RCPC operates in parallel

– Completely automated

• Process is divided into two sub-processes

– Model Builder (PowerGEM TARA AMB)

– ATC Calculator (OATi webTrans)

5

Equivalent ATC derived from Flowgate Methodology

&

Remaining Contract Path Capability (RCPC)

ATC Process – High Level

6

Model Builder

Model Builder (PowerGEM Automated Model Builder)

Model solver

RCPC

Calculation

ATC Calculator (OATi webTrans)

Calculates

Equivalent

ATC

Calculate

AFCs

Calculate

TDFs

Calculates

ATC ATCs

Flowgate Methodology Overview

7

Model

Builder

ATC

Calculator

TSRs AFCs

Flowgate

Def file

Seed

cases

Gen

Dispatch

NERC Tag Dump (NERC IDC)

Tags

Load

Forecasts

NERC SDX (System Data Exchange)

Transmission

& Generation

Outages

OASIS (OATi webOASIS)

TSRs ATC

System Data

AFCs

Coordinating FTP Sites (CPL, PJM, SC, SCEG,SOCO, TAP, TVA, YAD)

TSRs

FTP Site (OATi FTP Site)

RTDF

File

Model Builder

8

Model Builder


Model solver

GSFs

Baseflows

RTDF

File

Flowgate def file

Seed cases

Gen Dispatch

To FTP Site

What does the Model Builder do?

• Automatically creates & solves many models

• Consolidates output data into a single file

Tag Dump

Load

Forecasts

Transmission

Outages

Generation

Outages

Model Builder

• Building Models

– Builds a model for each increment of series

• e.g. Hourly48_no tags builds 48 models representing the next 48

hours

– Starts with applicable seed case

– Modifies seed case with input data

• Load, transmission & generation outages, as well as tags (only in

the Hourly48 models)

– Dispatches generation to meet load + interchange + losses

• Utilizes dispatch files

• Respects generation outages and reserve shut downs

9

Model Builder – Description of Model Series

• Model Builder schedule

10

Model Series # of Models

Created

Model

Increment Creation Schedule

Hourly 48_no tags 48 Hourly Every hour

Hourly 48 48 Hourly Every hour

Hourly 180 Hourly Runs up to 4 x daily

Daily 45 Daily Runs up to 3 x daily

Monthly 13 Monthly Runs up to 3 x daily

Creates 48 unique models specific to each hour

Model Builder – Hourly 48_no tags Example

11

Seed Case

Model

representing

05/25/12 00:00

Outages on

05/25/12

00:00

Load Forecast

for 05/25/12

00:00

Seed Case

Model

representing

05/25/12 01:00

Outages on

05/25/12

01:00

Load Forecast

for 05/25/12

01:00

Seed Case

Model

representing

05/25/12 02:00

Outages on

05/25/12

02:00

Load Forecast

for 05/25/12

02:00

Seed Case

Model

representing

05/27/12 00:00

Outages on

05/27/12

00:00

Load Forecast

for 05/27/12

00:00

Same Seed Case

Load Specific

to each hour

Outages

Specific to

each hour

Model Builder – Seed Case

• Seed cases

– Utilize cases developed by SERC Near-Term Study Group

• Developed quarterly for next 5 seasons

• Cases built with participation from all SERC Transmission Providers

• Heavily coordinated development

• Same cases used in Duke’s old Contract Path methodology

– Modified to align with NERC tools that provide load & outage

data

• NERC System Data Exchange (SDX)

• NERC Interchange Distribution Calculator (IDC)

12

Model Builder – Outages

• Outages imported from NERC System Data Exchange

(SDX)

– Automatically queries & downloads data every hour

• CPLE,CPLW, DUK, PJM, SC, SCEG, SEHA, SERU, SETH, SOCO,

TVA, TAP, & YAD

– Generation outages (typically 20 MWs +)

– Transmission outages (100 kV +)

• Apply outage criteria

– Hourly

– Daily

– Monthly

– RCPC

13

ATCID has detailed description of

outage criterion. Link to ATCID

http://www.oatioasis.com/DUK/DUKdocs/Current_Available_Transfer_Capability_Implementation_Document_-_ATCID.pdf

Model Builder – Outage Criteria

• Hourly48, Hourly48_no tags, & Hourly outage criteria

– Generator outages

• Typically greater than 20 MWs

• Short-Standby (SS) units considered as outaged

– Transmission outages

• Must be greater than or equal to 100 kV

• If all of the above criteria is met, the outaged facility is

modeled out of service each hour, between the outage

start & stop time

14

Model Builder – Outage Criteria (hourly example)

• For example: Jackson Ferry – Antioch 500 kV line

– Outaged 05/25/12 08:00 – 05/25/12 16:00

15

Made up scenario

05/25/12 08:00

Model

Line out-service

05/25/12 06:00

Model

Line in-service

05/25/12 07:00

Model

Line in-service

05/25/12 09:00

Model

Line out-service

05/25/12 15:00

Model

Line out-service

05/25/12 16:00

Model

Line in-service

Each hourly model has the line modeled

out-of-service during the outage period

• Daily outage criteria

– In order for an outage to be modeled as out-of-service in the

daily model, the generation or transmission outage must:

• Have an outage duration of at least 2 hrs in the “Daily Peak Period”

• Typically greater than 20 MWs (generators)

• Be greater than or equal to 100 kV (transmission)

– Daily Peak Period

• 8 hour window


16

Outage must be at least 2

hours long in the 8 hour

long “Daily Peak Period”.

Model Builder – Outage Criteria (daily example)


– Outaged 05/25/12 08:00 – 05/25/12 16:00

17

Made up scenario

05/24/12 Model

Line in-service

05/25/12 Model

Line out-service

05/26/12 Model

Line in-service

00:00 12:00 16:00 20:00 00:00 04:00 08:00

Jackson Ferry – Antioch 500 kV Outage

Daily Peak Period

outage window

Outage overlaps the Daily

Peak Period by 4 hours. > Required

2 hours

Model Builder – Outage Criteria (daily example)

• For example: Newport - Richmond 500 kV line

– Outaged 05/25/12 06:00 – 05/25/12 13:00

18

Made up scenario

05/24/12 Model

Line in-service

05/25/12 Model

Line in-service

05/26/12 Model

Line in-service

00:00 12:00 16:00 20:00 00:00 04:00 08:00

Newport - Richmond 500 kV Outage

Daily Peak Period

outage window

Outage overlaps the Daily

Peak Period by 1 hour. < Required

2 hours

• Monthly outage criteria

– In order for an outage to be modeled as out-of-service in the

monthly model, the generation or transmission outage must:

• Be outaged on the “Representative Day”

• Have an outage duration of at least 2 hrs in the “Daily Peak Period”

• Typically greater than 20 MWs (generators) & 100 kV or greater

(transmission)

– Representative Day

• 3rd Wednesday of the month

– Daily Peak Period

• 8 hour window


19

Outage must be on the “Representative

Day” AND at least 2 hours long in the 8

hour long “Daily Peak Period”.

Model Builder – Outage Criteria (monthly example)


– Outaged 05/01/12 08:00 – 05/15/12 16:00

20

04/12 Model

Line in-service

05/12 Model

Line in-service

06/12 Model

Line in-service

May 1 May 15 May 20 May 25 May 5 May 10

Jackson Ferry – Antioch 500 kV Outage

Representative Day

outage window

Outage does not occur on

“Representative Day”

Made up scenario

Model Builder – Outage Criteria (monthly example)

• For example: Newport - Richmond 500 kV line

– Outaged 05/16/12 08:00 – 05/16/12 16:00

21

04/12 Model

Line in-service

05/12 Model

Line out-service

06/12 Model

Line in-service

May 1 May 15 May 20 May 25 May 5 May 10

Newport - Richmond 500 kV Outage

Representative Day

Made up scenario

00:00 12:00 16:00 20:00 00:00 04:00 08:00

Daily Peak Period

Newport – Richmond 500 kV Outage


• This is what the transmission outage data looks like

22

Outage Criteria Example

• Initial conditions

– Generator A = 1500 MW

– Generator B = 250 MW

– Load B = 750 MW

• This reservation is used in the planning models, but can be

tagged/scheduled at a lower level in the operating horizon.

– Rating of Station A-B ckt 1&2 are 500 MWs/line

• We want to know the baseflow or initial AFC on Flowgate

# 42444, Station A-B 1 flo Station A-B 2 for the Month of

May.

23

Outage Criteria Example – Initial Conditions

24

Station A

A

Station B

B

AFC monthly base flow for May 2012

42444 Station A-B 1 flo Station A-B 2 = 500 – 250 - .5(250) = 125

Flowgate A-B ckt 1

Flowgate A-B ckt 2

1,500 MWs 250 MWs

500 MWs

500 MWs

250 MWs

250 MWs

750 MWs

Flowgate A-B ckt 1 rating = 500


Outage Criteria Example – Apply Outage

• How does a maintenance outage at Station B affect our

initial monthly AFCs for the month of May on flowgate

42444?

25


26

Station A

A

Station B

B

Generator B maintenance schedule

5/14 08:00 – 5/21 23:59

Flowgate A-B ckt 1

Flowgate A-B ckt 2

1,500 MWs 0 MWs

375 MWs

375 MWs

375 MWs

375 MWs

750 MWs




42444 Station A-B 1 flo Station A-B 2 = 500 – 375 - .5(375) = -62.5


• We now know that monthly AFCs for the month of May

are negative due to this generator outage, but how do our

initial AFCs look as we get closer to the scheduled

outage window?

27


• Daily Firm/Non-Firm AFC

28

Date AFC

5/12 125

5/13 125

5/14 -62.5

5/15 -62.5

5/16 -62.5

5/17 -62.5

5/18 -62.5

5/19 -62.5

5/20 -62.5

5/21 -62.5

5/22 125

5/23 125

5/24 125

5/25 125


• Hourly Planning Firm/Non-Firm AFC from 5/14 at 00:00

29

Date AFC

5/14 0000 125

5/14 0100 125

5/14 0200 125

5/14 0300 125

5/14 0400 125

5/14 0500 125

5/14 0600 125

5/14 0700 125

5/14 0800 -62.5

5/14 0900 -62.5

5/14 1000 -62.5

5/14 1100 -62.5

5/14 1200 -62.5

5/14 1300 -62.5


• Load B decides that it is not going to need the firm

transaction and decides to release 500 MW of this firm for

5/14. How does this change the AFC that is being

calculated?

30


31

Station A

A

Station B

B

Generator B maintenance schedule

5/14 0800 – 5/21 2359

Flowgate A-B ckt 1

Flowgate A-B ckt 2

1,500 MWs 0 MWs

625 MWs

625 MWs

125 MWs

125 MWs

250 MWs




42444 Station A-B 1 flo Station A-B 2 = 500 – 125 - .5(125) = 312.5


• Hourly Operating Firm/Non-Firm AFC from 5/14 at 00:00

32

Date

5/14 0000

5/14 0100

5/14 0200

5/14 0300

5/14 0400

5/14 0500

5/14 0600

5/14 0700

5/14 0800

5/14 0900

5/14 1000

5/14 1100

5/14 1200

5/14 1300

AFC Non-Firm

312.5

312.5

312.5

312.5

312.5

312.5

312.5

312.5

312.5

312.5

312.5

312.5

312.5

312.5

AFC Firm

125

125

125

125

125

125

125

125

-62.5

-62.5

-62.5

-62.5

-62.5

-62.5

Outage Criteria Example – Questions?

• Completed walk-thru of the outage criteria example

problem

– Up next: Model Builder – Load Forecasts

33

Model Builder – Load Forecasts

• Load imported from NERC System Data Exchange (SDX)

– Automatically queries & downloads data every hour

– CPLE,CPLW, DUK, PJM, SC, SCEG, SEHA, SERU, SETH,

SOCO, TVA, TAP, & YAD

• For PJM, load imported from file provided by PJM

– Breaks out load forecasts for each of PJM’s legacy Balancing

Authorities

– Automatically downloads data every hour

– Increases model accuracy

34

Model Builder – Load Forecast

• This is what the hourly load data looks like

35

Model Builder – Generation Dispatch

• Duke Energy Carolinas generation dispatch

– Block Dispatch File

• Groups units into blocks based on dispatch order

– Direct Dispatch Files

• Pumped Storage (based on Duke unit commitment 7-day outlook

forecast)

• IPPs – Based on tags in hourly operating horizon

• Adjacent TSP generation dispatch

– Block Dispatch File (provided by adjacent TSP)

– Direct Dispatch Files (if provided)

36

Model Builder

37

Model Builder


Model solver

GSFs

Baseflows

RTDF

File

Flowgate def file

Seed cases

Gen Dispatch

To FTP Site Tag Dump

Load

Forecasts

Transmission

Outages

Generation

Outages

We just went over

building models

Model Builder

38

Model Builder


Model solver

GSFs

Baseflows

RTDF

File

Flowgate def file

Seed cases

Gen Dispatch

To FTP Site Tag Dump

Load

Forecasts

Transmission

Outages

Generation

Outages

We will now look at solving

models & output data

Model Builder

• Solving Models & Output Data

– Solves each model

• AC solution with internal Decoupled Newton Solution algorithm

– Calculates for each model:

• Baseflow on every flowgate

• Generation Shift Factors (GSFs)

– For each flowgate with respect to each POR/POD

– Combines Baseflow & GSF data into single output file

• RTDF file

39

Model Builder – Questions?

• Completed walk-thru of Model Builder

– Up next: ATC Calculator

40

Flowgate Methodology Overview

41

Model

Builder

ATC

Calculator

TSRs AFCs

Flowgate

Def file

Seed

cases

Gen

Dispatch

NERC Tag Dump (NERC IDC)

Tags

Load

Forecasts

NERC SDX (System Data Exchange)

Transmission

& Generation

Outages


TSRs ATC

System Data

AFCs

Coordinating FTP Sites (CPL, PJM, SC, SCEG,SOCO, TAP, TVA, YAD)

TSRs

FTP Site (OATi FTP Site)

RTDF

File

ATC Calculator

42

RCPC

Calculation


Calculates

Equivalent

ATC

Flowgate def file

AFCs from

Adjacent TPs

RTDF Files

TSRs from

Adjacent TPs

TSRs from

Duke OASIS

Tags from

webTag

Calculate

AFCs

Calculate

TDFs

Calculates

ATC

TRM & CBM

data

AFCs

ATCs

TSRs

To OASIS

To FTP

Site


• Very similar to the old Area Interchange Methodology

(a.k.a. Contract Path Methodology)

• Respects tie line capability with adjacent BAs

• Reflects the capacity remaining on those tie lines

– Includes the impact of:

• TRM – Transmission Reliability Margin

• Reservations/schedules

43


44

RCPC

Calculation

ATC Calculator (OATi webTrans Software)


TSRs

Tagging System (OATi webTag)

Tags OATi

OATi

Manual Process

Interface Ratings

to Adjacent BAs

(MWs)

TRM

(MWs)

Automated Process


45

Interface Ratings

to Adjacent BAs

(MWs)

Summation of facility ratings interconnecting

Duke to each adjacent BA

DUK PJM

DUK-PJM Interface Rating

2003 MWs

Tie line #2 – Rating = 130 MWs

For Example:

Tie line #1 – Rating = 1,873 MWs

RCPC Calculation

Firm Equation

RCPC = Contract Path (CP) Limit – TRM – CBM - Firm TSRs

Non-Firm Equation – Prior to 08:00 day prior

RCPC = CP Limit – TRM – CBM –Firm TSRs –Non-Firm TSRs

Non-Firm Equation – After 08:00 day prior

RCPC = CP Limit – TRM – CBM – Scheduled Firm – Non-Firm TSRs

Facilitates the release of unscheduled-firm capacity to the non-firm RCPC

Scheduled Firm = Capacity of firm reservation that

is tagged (transmission profile)

46

RCPC Calculation

• Wheel-Through Paths

– RCPC is the minimum of the two import/export paths that

comprise the wheel-through path

– For example, PJM-SOCO wheel-through path:

47

DUK PJM SOCO

PJM SOCO

RCPC = 2,003 MWs RCPC = 2,499 MWs

RCPC = 2,003 MWs

PJM-SOCO contract path Is the

minimum of PJM-DUK & DUK-SOCO

RCPC Calculation Questions?

• Completed walk-thru of RCPC

48

RCPC

Calculation


Calculates

Equivalent

ATC

Calculate

AFCs

Calculate

TDFs

Calculates

ATC

– Up next: ATC Calculator

ATC Calculator – Calculate TDFs

• Calculate Transfer Distribution Factors (TDFs)

– Performed for every flowgate with respect to every path

– Based on the RTDF file imported from the Model Builder

• Uses the GSFs from the RTDF file

• TDF = GSFPOR – GSFPOD

– Expressed as a percentage (%)

49

TDF Example Problem

• Lets take a look at flowgate x and how the TDFs affect

this flowgate

50

DUK CPLW

DUK – CPLW

Flowgate x

TDF Example Problem

• Basic Principle

– In order to do a Duke to CPLW transfer, we have to increase

generation in Duke and decrease generation in CPLW.

– When we do this, the AFC process looks at the Generation Shift

Factor (GSF) for each flowgate defined in AFC process and

calculates the % impact of moving that generation.

51

TDF Example Problem

• The GSFs associated with a POR of DUK is “DUK_R” and

a POD of CPLW is “CPLW_D”

• The AFC process then calculates a TDF for flowgate x

with respect to the DUK-CPLW path

– TDF = GSFPOR-GSFPOD

– For our example, it would be:

• TDFflowgate x | for DUK-CPLW = GSFPOR (DUK_R) – GSFPOD (CPLW_D)

52

TDF Example Problem

• In this example, we are:

– Increasing generation in DUK and decreasing generation in

CPLW, analyzing the affects this has on flowgate x

53

DUK CPLW

DUK - CPLW

Flowgate x

TDF Example Problem

• The GSF from webTrans for DUK_R = 0.010260

• The GSF from webTrans for CPLW_D = -0.091550

54

Flowgate x

Flowgate x

TDF Example Problem

• Remember:

– TDFflowgate x | for DUK-CPLW = GSFPOR (DUK_R) – GSFPOD (CPLW_D)

– Using the numbers from webTrans:

• TDFflowgate x | for DUK-CPLW = 0.010260 – (-0.091550)

• TDFflowgate x | for DUK-CPLW = 0.010260 + 0.091550

• TDFflowgate x | for DUK-CPLW = 0.101736 = 10.1736%

55

TDF Example Problem

• What does it all mean?

– At 10% TDF, The AFC number calculated in the AFC process for

a DUK-CPLW transfer would be used whether it is an internal

flowgate (>3%) or an external flowgate (>5%).

– This is done for all defined flowgates in the AFC process with

respect to the DUK-CPLW path

56

TDF Example Problem – Questions?

• Completed walk-thru of TDF Example Problem

– Up next: ATC Calculator – Calculate AFCs

57

ATC Calculator – Calculate AFCs

• Firm AFC equation

– AFCFirm = TFC – CBM – TRM – Baseflow – FRESN

• Non-Firm AFC equation (Prior to 08:00 day prior)

– AFCNon-Firm = TFC – CBM – TRM – Baseflow – FRESN – NFRES

• Non-Firm AFC equation (After 08:00 day prior)

– AFCNon-Firm = TFC – CBM – TRM – Baseflow* – NFRES*

* NFRES – Non-firm reservations only impact ATC for a short time or until they are tagged. Baseflow term contains impacts of

firm & non-firm tags.

Where: TFC = Total Flowgate Capability

FRESN = Firm reservation impacts

NFRES = Non-firm reservation impacts

58

ATC Calculator – Calculate AFCs

• Coordinated AFC Values

– AFCs calculated by adjacent Transmission Providers for their

flowgates honored in the Duke ATC process

– Supersedes Duke’s calculated values

• Duke’s calculated values only used if coordinating entity has not

provided any values

– Required by FERC mandatory NERC MOD Reliability Standard

• R5.3 “For external Flowgates, identified in R2.1.4, use the AFC

provided by the Transmission Service Provider that calculates AFC

for that Flowgate.” (NERC MOD-030-02)

59

http://www.nerc.com/files/MOD-030-2.pdf





ATC Calculator – Calculate Equivalent ATC

Equivalent ATCP = Minimum

Where: ATCp = Available Transfer Capability on path p

AFCn = Available Flowgate Capability of flowgate n

TDFn,p = Transfer Distribution Factor for flowgate n with respect to

path p.

NOTE: The Equivalent ATC calculation only considers flowgates that are “impacted” by the path p. In other

words, the TDF of flowgate n must be at or above 3% for internal flowgates and 5% for external

flowgates.

60

𝐴𝐹𝐶1

𝑇𝐷𝐹1, 𝑝

,𝐴𝐹𝐶2

𝑇𝐷𝐹2, 𝑝

,𝐴𝐹𝐶3

𝑇𝐷𝐹3, 𝑝

, … 𝐴𝐹𝐶𝑛

𝑇𝐷𝐹𝑛, 𝑝

ATC Calculator – Calculate ATC

ATC = Minimum

ATC posted to OASIS for each path

– Located in System Data

– Firm & non-firm ATC for each posted path

61


&

Equivalent ATC derived from Flowgate Methodology

ATC Calculator – Questions?

• Completed walk-thru of ATC Calculator

62

RCPC

Calculation


Calculates

Equivalent

ATC

Calculate

AFCs

Calculate

TDFs

Calculates

ATC

Comments on ATC

ATC • Driven by RCPC & Equivalent ATC

Equivalent ATC • Driven by AFC & TDF

TDF • Driven by outages & load/Gen dispatch

AFC

63

• Driven by baseflow

& market activity

Why are AFC numbers so different from one

horizon to another?

• There are several reasons AFC can change

– Generation/Transmission Outages

• Scheduled and forced outages can have a drastic impact on AFC

calculations

– Load forecast

• Due to weather forecast changes, this can have a drastic impact on

the generation mix used not only for Duke, but for our neighboring

BAs as well. This will have an impact on the base flow and TDF

calculations.

– Adjacent Transmission Provider coordinated flowgates

64

For More Information…

• Available Transfer Capability Implementation Document

(ATCID)

– http://www.oatioasis.com/DUK/DUKdocs/Current_Available_Tra

nsfer_Capability_Implementation_Document_-_ATCID.pdf

• Attachment C of the OATT

– http://www.oatioasis.com/DUK/DUKdocs/DukeCarolinaOATT.pdf

• January 19, 2012 Stakeholder ATC Training Presentation

– http://www.oatioasis.com/DUK/DUKdocs/Q4_20120119_-

_ATC_Training_Presentation.pptx

• ATC Methodology Contact

– (651) 632-8708

– [email protected]

65






http://www.oatioasis.com/DUK/DUKdocs/DukeCarolinaOATT.pdf

http://www.oatioasis.com/DUK/DUKdocs/DukeCarolinaOATT.pdf

http://www.oatioasis.com/DUK/DUKdocs/Q4_20120119_-_ATC_Training_Presentation.pptx




mailto:[email protected]

Questions?

• Any questions about the material we just went over?

• Do you have questions/concerns about the ATC process

in general?

• Was this training session of value to you?

66

available transfer capability - oasis.oati.com terms • afc – available flowgate capability •...

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