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APPENDIX A CONNECTION ASSESSMENT

Connection Engineering Study Report for AUC Application 1903 FortisAlberta East Yellowhead Area Capacity and Reliability Project

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Executive Summary

Project Overview

FortisAlberta Inc. (FortisAlberta), in its capacity as the legal owner of an electric distribution system (DFO), has submitted a request for system access service to the Alberta Electric System Operator (AESO), to reliably serve load growth in the area east of the Town of Edson .

The DFO’s request for system access service includes a request for a Rate DTS, Demand Transmission Service, contract capacity increase of 3.9 MW, from 17.2 MW to 21.1 MW, for the system access service provided at the existing Pinedale 207S substation, and a request for transmission development (collectively, the Project). Specifically, the DFO requested upgrades to the existing Pinedale 207S substation.

The scheduled In-Service Date (ISD) for the Project is November 1, 2018.

The report details the engineering studies conducted to assess the impact of the Project on the performance of the Alberta Interconnected Electric System (AIES).

Existing System

Geographically, the Project is located in the AESO planning area of Hinton/Edson (Area 29), which is part of the AESO Central Planning Region.

From a transmission system perspective, Hinton/Edson (Area 29) consists primarily of a 138 kV transmission system. The Hinton/Edson area is mainly supplied from the 240/138 kV Bickerdike 39S Substation. The tie lines connecting Hinton/Edson (Area 29) to the rest of the AIES are the 138 kV transmission lines 202L, 744L, and 685L; and the 240 kV transmission lines 973L and 974L.

Study Summary

Study Area for the Project

The Study Area for the Project consists of Hinton/Edson (Area 29) and the tie lines connecting Hinton/Edson (Area 29) to the rest of the AIES. All transmission facilities within the Study Area were studied and were monitored to assess the impact of the Project on the performance of the AIES, including any violations of the Reliability Criteria (as defined in Section 2.1.1).

Studies Performed for the Project

Power flow studies were performed for the 2018 summer peak (SP) and 2018 winter peak (WP) pre-Project and post-Project scenarios.

Voltage stability studies were performed for the 2018 WP post-Project scenario.

Results of the Pre-Project Studies

No Reliability Criteria violations were observed under Category A or Category B conditions.


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Connection Alternatives

The AESO, in consultation with the DFO and the legal owner of transmission facilities (TFO) examined two connection alternatives to meet the DFO’s request for system access service:

Alternative 1: Upgrade the Pinedale 207S substation

Alternative 1 involves upgrading the existing Pinedale 207S substation, including adding one 138/25 kV transformer, one 138 kV circuit breaker, one 25 kV feeder circuit breaker and associated equipment.

Alternative 2: Upgrade the T.M.P.L. Niton 228S substation

Alternative 2 involves upgrading the existing T.M.P.L. Niton 228S substation, including adding one 138/25 kV transformer, upgrading the existing voltage regulator to 25 MVA, and adding one 25 kV feeder circuit breaker. In addition, Alternative 2 also involves converting the connection for T.M.P.L Niton 228S substation from a T-tap configuration to an in-and-out configuration by adding three 138 kV circuit breakers and associated equipment. To complete the required upgrades, the TFO has advised that modification of the 138 kV bus and expansion of the substation fence would be required.

Connection Alternative Selected for Further Examination

Alternative 1 was selected for further examination. Alternative 2 would involve increased transmission development, and hence overall increased cost, compared to Alternative 1. Therefore, Alternative 2 was not selected for further study.

Results of the Post-Project Studies

No Reliability Criteria violations were observed under Category A or Category B conditions.

The voltage stability margin was met for all studied conditions.

Conclusions and Recommendations

Based on the study results, Alternative 1 is technically viable.

It is recommended to proceed with the Project using Alternative 1 as the preferred option to respond to the DFO’s request for system access service.


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Contents Executive Summary ..................................................................................................................... i Introduction .......................................................................................................................... 1 1

1.1 Project ........................................................................................................................................... 1 1.1.1 Project Overview ............................................................................................................................... 1 1.1.2 Load Component ............................................................................................................................... 1 1.1.3 Generation Component ..................................................................................................................... 1

1.2 Study Scope .................................................................................................................................. 1 1.2.1 Study Objectives ................................................................................................................................ 1 1.2.2 Study Area ......................................................................................................................................... 2 1.2.3 Studies Performed ............................................................................................................................. 3

1.3 Report Overview........................................................................................................................... 4 Criteria, System Data and Study Assumptions ................................................................. 5 2

2.1 Criteria, Standards and Requirements .......................................................................................... 5 2.1.1 AESO Standards and Reliability Criteria ........................................................................................... 5 2.1.2 ISO Rules and Information Documents ............................................................................................. 6

2.2 Study Scenarios ............................................................................................................................ 6 2.3 Load and Generation Assumptions ............................................................................................... 6

2.3.1 Load Assumptions ............................................................................................................................. 6 2.3.2 Generation Assumptions ................................................................................................................... 7 2.3.3 Intertie Flow Assumptions ................................................................................................................. 7 2.3.4 High-Voltage Direct Current Power Order ......................................................................................... 7

2.4 System Projects ............................................................................................................................ 8 2.5 Connection Projects ...................................................................................................................... 8 2.6 Facility Ratings and Shunt Elements ............................................................................................ 8

Study Methodology ............................................................................................................ 10 33.1 Connection Studies Carried Out ................................................................................................. 10 3.2 Power Flow Studies .................................................................................................................... 10

3.2.1 Contingencies Studied ..................................................................................................................... 10 3.3 Voltage Stability Studies ............................................................................................................. 11

3.3.1 Contingencies Studied ..................................................................................................................... 11 Pre-Project System Assessment ...................................................................................... 12 4

4.1 Power Flow .................................................................................................................................. 12 4.1.1 Scenario 1 – 2018 SP Pre-Project ................................................................................................... 12 4.1.2 Scenario 2 – 2018 WP Pre-Project .................................................................................................. 12

Connection Alternatives .................................................................................................... 13 55.1 Overview ..................................................................................................................................... 13 5.2 Connection Alternatives Examined ............................................................................................. 13

Technical Analysis of the Connection Alternative ......................................................... 14 66.1 Power Flow .................................................................................................................................. 14

6.1.1 Scenario 3 – 2018 SP Post-Project ................................................................................................. 14 6.1.2 Scenario 4 – 2018 WP Post-Project ................................................................................................ 14


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6.2 Voltage Stability........................................................................................................................... 14 6.2.1 Scenario 4 – 2018 WP Post-Project ................................................................................................ 14

Project Dependencies ....................................................................................................... 15 7 Conclusions and Recommendations ............................................................................... 16 8

Tables Table 2–1: Post-Contingency Voltage Deviation Guidelines for Low Voltage Busses ......................... 6 Table 2-2: List of Connection Study Scenarios ..................................................................................... 6 Table 2-3. Forecast Area Load ............................................................................................................. 7 Table 2-4. Existing Local Generation Dispatch in the Study Scenarios ................................................ 7 Table 2-5. Connection Projects Included in the Studies ....................................................................... 8 Table 2-6. Key Transmission Line Ratings in the Study Area (MVA on a 138 kV Base) ...................... 8 Table 2-7. Ratings of Key Transformers in the Study Area .................................................................. 9 Table 2-8. Details of Shunt Elements in the Study Area ....................................................................... 9 Table 3-1. Engineering Studies Performed ......................................................................................... 10 Table 6-1. Voltage Stability Results for the 2018 WP Post-Project Scenario ..................................... 14

Figures Figure 1-1. Existing Transmission System in the Study Area ............................................................... 3

Attachments Attachment A: Pre-Project Power Flow Diagrams Attachment B: Post-Project Power Flow Diagrams Attachment C: Post-Project Voltage Stability Diagrams


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Introduction 1This report details the engineering studies conducted to assess the impact of the Project (as defined below) on the performance of the Alberta interconnected electrical system (AIES).

1.1 Project

1.1.1 Project Overview FortisAlberta Inc. (FortisAlberta), in its capacity as the legal owner of an electric distribution system (DFO), has submitted a request for system access service to the Alberta Electric System Operator (AESO), to reliably serve load growth in the area east of the Town of Edson.

The DFO’s request for system access service includes a request for a Rate DTS, Demand Transmission Service, contract capacity increase of 3.9 MW, from 17.2 MW to 21.1 MW, for the system access service provided at the existing Pinedale 207S substation, and a request for transmission development (collectively, the Project). Specifically, the DFO requested upgrades to the existing Pinedale 207S substation.

The scheduled In-Service Date (ISD) for the Project is November 1, 2018.

1.1.2 Load Component The Project includes a load component:

The existing Rate DTS contract capacity at the Pinedale 207S substation is 17.2 MW.

The DFO requested a Rate DTS contract capacity of 21.1 MW at the Pinedale 207Ssubstation

The project load was studied assuming a 0.9 power factor (pf) lagging.

Load type: Residential, farm, commercial and industrial loads.

1.1.3 Generation Component There is no generation component associated with the Project.

1.2 Study Scope

1.2.1 Study Objectives The objective of the study is as follows:

Assess the impact of the Project on the performance of the AIES.

Identify any violations of the relevant AESO criteria, standards or requirements, bothpre-Project and post-Project.

Recommend mitigation measures, if required, to reliably connect the Project to the AIES.


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1.2.2 Study Area

1.2.2.1 Study Area Description

Geographically, the Project is located in the AESO planning area of Hinton/Edson (Area 29), which is part of the AESO Central Planning Region.

From a transmission system perspective, Hinton/Edson (Area 29) consists primarily of a 138 kV transmission system. The Hinton/Edson area is mainly supplied from the 240/138 kV Bickerdike 39S Substation. The tie lines connecting Hinton/Edson (Area 29) to the rest of the AIES are the 138 kV transmission lines 202L, 744L, and 685L; and the 240 kV transmission lines 973L and 974L.

The existing Pinedale 207S substation is a point of delivery (POD) substation, which is connected to the AIES by two existing 138 kV transmission lines:

138 kV transmission line 890L, which connects the Pinedale 207S substation and the Edson 58Ssubstation; and,

138 kV transmission line 744L, which connects the Pinedale 207S substation and the T.M.P.L.Niton 228S substation.

The Study Area for the Project consists of Hinton/Edson (Area 29) and the tie lines connecting Hinton/Edson (Area 29) to the rest of the AIES. All transmission facilities within the Study Area were studied and were monitored to assess the impact of the Project on the performance of the AIES, including any violations of the Reliability Criteria (as defined in Section 2.1.1).

The existing transmission system in the Study Area is shown in Figure 1-1.


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Figure 1-1 Existing Transmission System in the Study Area

1.2.2.2 Existing Constraints

The existing constraints in Central Region are managed in accordance with the procedures set out in Section 302.1 of the ISO rules, Real Time Transmission Constraint Management (TCM Rule).

1.2.2.3 AESO Long-Term Transmission Plan

The AESO 2015 Long-term Transmission Plan (2015 LTP) does not include any developments within the Hinton/Edson area, which is part of the Central West sub-region.

1.2.3 Studies Performed The following studies were performed for the pre-project scenarios:

Power flow studies

The following studies were performed for the post-Project scenarios:

Power flow studies

Voltage stability studies

740L

745L

BRAZEAUOUTLET WORKS

294S

847L

744L (to PaddleRiver 106S)

202L (toLodgepole61S)

801L (toBrazeau

62S)

DEER HILL1012S

854L

P1903: FortisAlberta EastYellohead Area Capacity

and Reliability ProjectEDSON58S

CHEVIOT101S

CADOMIN983S

COALSPUR426S

MARLBORO348S

GULFROBB414S

BICKERDIKE39S

DALEHURST975S

COLDCREEK

602S

COALVALLEY

527S

FICKLE LAKE406S

WATSONCREEK 104S

CARDINALRIVER 302S

MOUNTAINCOALOBED

411S

MANALTA COALGREGG RIVER 476S

740L

762L

745L

685L

(to

Benb

ow39

7S)

501L

615L

847L

743L

671L

745AL

740AL

973L/974L (toSundance 310P)

501CL

854AL

745A1L

742AL

Weldwood #1 & 2(WWD1-WWD2)

TalismanEdson (TLM2)

29 - Hinton / Edson

30 - Drayton Valley

BRAZEAU358S

CYNTHIA178S

PINEDALE207S

WESTPEMBINA

359S

WESTPEMBINA

477S

T.M.P.L.NITON228S

PETRO CANADA BRAZEAU RIVER

489S

ELK RIVER445S

202L

801L

744L

828L

841L

890L

844L

P1903 AreaTransmission System

This diagram contains a simplifiedversion of the system configuration.Technical detail has been simplifiedfor illustration purposes. It does not

indicate geographical locations of facilities.

Gas Generator

Other Generator

69 or 72 kV Substation

138 or 144 kV Substation

240 kV Substation

69/72 kV

138/144 kV

240 kV Double Circuit

P1903 Project Area

AESO Planning AreasCurrency Date: 2017-01-19


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1.3 Report Overview

The Executive Summary provides a high-level summary of the study and its conclusions. Section 1 provides an introduction to the Project and provides a high-level description of the study scope. Section 2 describes the criteria, system data, and other assumptions used in the studies. Section 3 describes the study methodology. Section 4 discusses the pre-Project studies results. Section 5 presents the alternatives examined and selected for further study. Section 6 provides post-Project studies results. Section 7 identifies any dependencies the Project may have. Section 8 presents the conclusions and recommendations of this assessment.


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Criteria, System Data and Study Assumptions 2

2.1 Criteria, Standards and Requirements

2.1.1 AESO Standards and Reliability Criteria The Transmission Planning (TPL) Standards, which are included in the Alberta Reliability Standards, and the AESO’s Transmission Planning Criteria – Basis and Assumptions (collectively, the Reliability Criteria) were applied to evaluate system performance under Category A system conditions (i.e., all elements in-service) and following Category B contingencies (i.e., single element outage), prior to and following the studied alternatives. Below is a summary of Category A and Category B system conditions.

Category A, often referred to as the N-0 condition, represents a normal system with no contingencies and all facilities in service. Under this condition, the system must be able to supply all firm load and firm transfers to other areas. All equipment must operate within its applicable rating, voltages must be within their applicable range, and the system must be stable with no cascading outages.

Category B events, often referred to as an N-1 or N-G-1 with the most critical generator out of service, result in the loss of any single specified system element under specified fault conditions with normal clearing. These elements are a generator, a transmission circuit, a transformer, or a single pole of a DC transmission line. The acceptable impact on the system is the same as Category A. Planned or controlled interruptions of electric supply to radial customers or some local network customers, connected to or supplied by the faulted element or by the affected area, may occur in certain areas without impacting the overall reliability of the interconnected transmission systems. To prepare for the next contingency, system adjustments are permitted, including curtailments of contracted firm (non-recallable reserved) transmission service electric power transfers.

The Alberta Reliability Standards include the Transmission Planning (TPL) standards that specify the desired system performance under different contingency categories with respect to the Applicable Ratings. The transmission system performance under various system conditions is defined in Appendix 1 of the TPL standards. For the purpose of applying the TPL standards to this study, the Applicable Ratings shall mean:

Seasonal continuous thermal rating of the line’s loading limits.

Highest specified loading limits for transformers.

For Category A conditions: Voltage range under normal operating condition per the AESOInformation Document #2010-007RS General Operating Practices – Voltage Control(ID #2010-007RS). ID #2010-007RS relates to Section 304.4 of the ISO rules, MaintainingNetwork Voltage. For the busses not listed in ID #2010-007RS, Table 2-1 in the TransmissionPlanning Criteria – Basis and Assumptions applies.

For Category B conditions: The extreme voltage range values per Table 2-1 in theTransmission Planning Criteria – Basis and Assumptions.

Desired post-contingency voltage change limits for three defined post event timeframes asprovided in Table 2–1, below.


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Table 2–1 Post-Contingency Voltage Deviation Guidelines for Low Voltage Busses

Parameter and Reference Point Time Period

Post-Transient (Up to 30 sec.)

Post-Auto Control (30 sec. to 5 min.)

Post-Manual Control (Steady State)

Voltage deviation from steady state at POD low voltage bus ±10% ±7% ±5%

2.1.2 ISO Rules and Information Documents ID # 2010-007RS was applied to establish pre- contingency voltage profiles in the Study Area. The TCM Rule was followed in setting up the study scenarios and assessing the impact of the Project. In addition, due regard was given to the AESO’s Connection Study Requirements document and the AESO’s Generation and Load Interconnection Standard.

2.2 Study Scenarios

The scheduled ISD of the Project is November 1, 2018. Therefore, the studies were performed using the 2018 summer peak (SP) and 2018 winter peak (WP) scenarios.

Table 2-2 provides a list of the study scenarios. This connection assessment will assume 0.9 pf lagging for the load associated with the Project.

Table 2-2 List of Connection Study Scenarios

Scenario No.

Year/Season Load

Pre-Project/ Post Project

Project Load (MW)

Total Pinedale

207S Substation Load (MW)

1 2018 SP Pre-Project 0 17.2

2 2018 WP Pre-Project 0 17.2

3 2018 SP Post-Project 3.9 21.1

4 2018 WP Post-Project 3.9 21.1

2.3 Load and Generation Assumptions

2.3.1 Load Assumptions The AESO planning area and region forecasts used for the studies are shown in Table 2-3 and are based on the AESO 2016 Long-term Outlook (2016 LTO) at Central Planning Region peak. For the studies, when POD loads for the Alberta internal load (AIL) were modified to align with the load forecast from the 2016 LTO, the active power to reactive power ratio in the base case scenarios was maintained. While the AESO has updated its regional forecasts since the connection studies were performed, the use of the


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current AESO forecast, the AESO 2017 Long-term Outlook, would not materially alter the connection study results or affect the conclusions and recommendations in this report.

Table 2-3 Forecast Area Load

AESO Planning Area or Region Forecast Peak Load (MW)

2018 SP 2018 WP

Hinton/Edson (Area 29) 142 145

AESO Central Planning Region 1999 2278

2.3.2 Generation Assumptions The generation assumptions for the studies are described in Table 2-4. The study identified the Weldwood #2 generating unit as the critical generator and it is turned off to represent the N-G study condition for all studies.

Table 2-4 Existing Local Generation Dispatch in the Study Scenarios

Generating Facility Unit Name Bus No.

AESO Planning

Area

Pmax (MW)

Unit Net Generationa (MW)

2018 SP 2018 WP

Weldwood #1 4017 29 20 12 10

Weldwood #2 (N-G) 4017 29 30 N-Gb

Edson 13020 29 13 6 8

a “Unit Net Generation” refers to gross generating unit output (MW) less unit service load. b “N-G” indicates the critical generating unit that is assumed by the AESO to be offline to test the N-G contingency condition

2.3.3 Intertie Flow Assumptions Intertie assumptions are included for the British Columbia-Alberta (BC-AB), Saskatchewan-Alberta (SK-AB), and Montana-Alberta Tie Line (MATL) interties. The interties were deemed to be far away from the Study Area to have any material effect on the assessment of the Project’s impact on the performance of the AIES. Therefore, the AESO planning base case intertie flow assumptions were used for the studies.

2.3.4 High-Voltage Direct Current Power Order The Western Alberta Transmission Line (WATL) and the Eastern Alberta Transmission Line (EATL) are high-voltage direct current (HVDC) transmission lines. Both of the HVDC transmission lines are expected to have minimal effect on the assessment of the Project’s impact on the performance of the AIES. Therefore, the AESO planning base case HVDC assumptions were used for the studies.


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2.4 System Projects

No system projects were included in the study scenarios.

2.5 Connection Projects

Table 2-5 lists the other connection project in the study area that was included in the studies.

Table 2-5 Connection Projects Included in the Studies

AESO Planning Area No.

Scheduled ISD AESO Project Name

AUC Decision

No.

AUC NID Approval

No.

Date of original

AUC approval

AESO Project

No.

Project Load (MW)

29 February 2019 Fortis New Hornbeck

Substation 22014-

D01-2016

22014-D02-2016

Dec 14, 2016 1460 18.0

2.6 Facility Ratings and Shunt Elements

The legal owner of transmission facilities (TFO) provided the thermal ratings for the existing transmission lines in the Study Area. The seasonal continuous ratings and short-term emergency ratings for the key transmission lines in the Study Area are shown in Table 2-6.

Table 2-6 Key Transmission Line Ratings in the Study Area (MVA on a 138 kV Base)

Line ID Line Description Voltage Class (kV)

Seasonal Continuous

Rating (MVA)

Short-term Emergency Rating

(MVA)

Summer Winter Summer Winter

615L Cold Creek 602S - Watson Creek 104S 138 120 145 132 160

745L Bickerdike 39S - Cold Creek 602S 138 172 212 189 233

671L Bickerdike 39S - Edson 58S 138 172 212 189 233

847L Bickerdike 39S - Cold Creek 602S 138 121 148 133 163

740L Bickerdike 39S - Coalspur 426S 138 99 133 109 146

740L Bickerdike 39S - Edson 58S 138 112 135 124 146

854L Marlboro 348S tap - Deer Hill 1012S 138 283 287 311 373

854L Marlboro 348S tap – Hornbeck 345S 138 263 263 311 373

685L Deer Hill 1015S - Benbow 397S 138 167 201 184 218

202L Edson 58S - Cynthia 178S 138 85 90 94 99

890L Edson 58S - Pinedale 207S 138 75 79 83 87


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Line ID Line Description Voltage Class (kV)

Seasonal Continuous

Rating (MVA)

Short-term Emergency Rating

(MVA)

Summer Winter Summer Winter

744L Pinedale 207S - T.M.P.L. Niton 228S 138 75 79 83 87

744L T.M.P.L. Niton 228S – 744AL Tap 138 75 79 83 87

744L 744AL Tap - Entwistle 235S 138 75 79 83 87

1150L Hornbeck 345S - Bickerdike 39S 138 172 172 212 212

973L Bickerdike 39S - Sundance 310P 240 333 333 499 499

974L Bickerdike 39S - Sundance 310P 240 333 333 499 499

The TFO also provided the facility ratings of the key existing transformers in the Study Area in Table 2-7.

Table 2-7 Ratings of Key Transformers in the Study Area

Substation Name and Number Transformer ID

Transformer Voltages (kV) MVA Rating

Bickerdike 39S 39ST1 240/138 269

39ST2 240/138 269

The details of shunt elements in the Study Area, as provided by the TFO, are shown in Table 2-8.

Table 2-8 Details of Shunt Elements in the Study Area

Substation Name and Number Voltage Class (kV)

Capacitors

Number of Switched Shunt

Blocks

Total at Nominal Voltage (MVAr)

Status in Study (on or off)

2018SP (MVAr)

2018WP (MVAr)

Cold Creek 602S 138 1 32.5

Switched as required

Edson 58S 138 1 27.1

Cynthia 178S 138 1 32

Amoco Brazeau 358S 138 1 21

Brazeau 62S 138 1 33

Violet Grove 283S 138 1 25


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3 Study Methodology The studies for this connection assessment were completed using PTI PSS/E version 33.

3.1 Connection Studies Carried Out

The studies that were completed for this connection assessment are identified in Table 3-1.

Table 3-1 Engineering Studies Performed

Scenario No. and Name System Conditions

Studies Performed

Power Flow Voltage

Stability

1 2018 SP Pre-Project Category A and Category B

2 2018 WP Pre-Project Category A and Category B

3 2018 SP Post-Project Category A and Category B

4 2018 WP Post-Project Category A and Category B

3.2 Power Flow Studies

Power flow studies were completed for all study scenarios to identify any thermal or transmission voltage violations as per the Reliability Criteria, and to identify any POD bus voltage deviations from the desired limits Table 2.1. The purpose of the power flow analysis is to quantify any violations in the Study Area for both pre-Project and post-Project study scenarios. For the Category B power flow studies, transformer taps and switched shunt reactive compensating devices such as shunt capacitors and reactors were locked and continuous shunt devices were enabled.

POD low voltage bus deviations were assessed for both the pre-Project and post-Project networks by first locking all tap changers and area shunt reactive compensating devices to identify any post-transient voltage deviations above 10%. Second, tap changers were allowed to move while shunt reactive compensating devices remained locked to determine if any voltage deviations above 7% would occur in the area. Third, all taps and shunt reactive compensating devices were allowed to adjust, and voltage deviations above 5%, if any, were reported.

3.2.1 Contingencies Studied Power flow studies were performed for all Category B contingencies (138 kV facilities and above) within the Study Area. All transmission facilities in the Study Area were monitored for Reliability Criteria violations.


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3.3 Voltage Stability Studies

The objective of the voltage stability analysis is to determine the ability of the network to maintain voltage stability at all the busses under Category A and Category B system conditions. The power-voltage (PV) curve is a representation of voltage change as a result of increased power transfer between two systems. The incremental transfers are reported to the collapse point.

Voltage stability studies were performed for the post-Project scenario only. For load connection projects, the load level modelled in post-Project scenarios is the same or higher than in pre-Project scenarios. Therefore, voltage stability analysis for pre-Project scenarios will only be performed if post-Project scenarios show voltage stability criteria violations.

Voltage stability (PV) analyses were performed according to the Western Electricity Coordinating Council (WECC) Voltage Stability Assessment Methodology. WECC voltage stability criteria state, for load areas, post-transient voltage stability is required for the area modeled at a minimum of 105% of the reference load level for Category A and Category B conditions. For this standard, the reference load level is the maximum established planned load.

Typically, voltage stability analysis is carried out assuming the worst case loading scenarios. For the Project’s worst case scenario, load was increased in the Study Area and the corresponding generation was increased in Calgary (Area 6), Medicine Hat (Area 4), and the Fort McMurray (Area 25) planning areas.

3.3.1 Contingencies Studied Voltage stability studies were performed for all Category B contingencies in the Study Area. All transmission facilities in the Study Area were monitored for Reliability Criteria violations.


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Pre-Project System Assessment 4

4.1 Power Flow

The pre-project power flow diagrams are provided in Attachment A.

4.1.1 Scenario 1 – 2018 SP Pre-Project No Reliability Criteria violations were observed under Category A or Category B conditions.

4.1.2 Scenario 2 – 2018 WP Pre-Project No Reliability Criteria violations were observed under Category A or Category B conditions.


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5 Connection Alternatives

5.1 Overview

The AESO, in consultation with the DFO and the TFO, examined two transmission alternatives to meet the DFO’s request for system access service.

5.2 Connection Alternatives Examined

Below is a description of the developments associated with the transmission alternatives that were examined for the Project.

Alternative 1: Upgrade the Pinedale 207S substation Alternative 1 involves upgrading the existing Pinedale 207S substation, including adding one 138/25 kV transformer, one 138 kV circuit breaker, one 25 kV feeder circuit breaker and associated equipment.

Alternative 2: Upgrade the T.M.P.L. Niton 228S substation Alternative 2 involves upgrading the existing T.M.P.L. Niton 228S substation, including adding one 138/25 kV transformer, upgrading the existing voltage regulator to 25 MVA, and adding one 25 kV feeder circuit breaker and associated equipment. In addition, Alternative 2 also involves converting the connection for the T.M.P.L Niton 228S substation from a T-tap configuration to an in-and-out configuration by adding three 138 kV circuit breakers and associated equipment. To complete the required upgrades, the TFO has advised that modification of the 138 kV bus and expansion of the substation fence would be required.

5.2.1. Connection Alternative Selected for Further Studies Alternative 1 is considered technically feasible and was selected for further study. 5.2.2. Connection Alternative Not Selected for Further Studies Alternative 2 would involve increased transmission development, and hence overall increased cost, compared to Alternative 1. Therefore, Alternative 2 was not selected for further study.


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Technical Analysis of the Connection Alternative 6

6.1 Power Flow

The post-Project power flow diagrams are provided in Attachment B.

6.1.1 Scenario 3 – 2018 SP Post-Project No Reliability Criteria violations were observed under Category A or Category B conditions.

6.1.2 Scenario 4 – 2018 WP Post-Project No Reliability Criteria violations were observed under Category A or Category B conditions.

6.2 Voltage Stability

6.2.1 Scenario 4 – 2018 WP Post-Project Voltage stability analysis was performed for the 2018 WP scenario. The reference load level for the Study Area is 145 MW. To meet the voltage stability criteria, the minimum incremental load transfer for the Category B contingencies is 5.0% of the reference load or 7.25 MW (0.05 x 145 MW = 7.25 MW). Voltage stability results for Category A and the worst five Category B contingencies are summarized in Table 6-1. The voltage stability margin was met for all studied conditions.

The voltage stability diagrams are shown in Attachment C.

Table 6-1 Voltage Stability Results for the 2018 WP Post-Project Scenario

Contingency From To Maximum

incremental transfer (MW)

Meets 105% transfer criteria?

Category A (N-G-0) 210 Yes

Edson 58S Transformer T1 n/a

120 Yes

Edson 58S Transformer T2 120 Yes

890L Edson 58S Pinedale 207S 120 Yes

1150L Bickerdike 39S Hornbeck 345S 120 Yes

974L (or 973L) Bickerdike 39S Sundance 310P 180 Yes


October 30, 2017

Final

15 Transmission

Public

Project Dependencies 7The Project does not require the completion of any AESO plans to expand or enhance the transmission system prior to connection.


October 30, 2017

Final

16 Transmission

Public

8 Conclusions and Recommendations Based on the study results, Alternative 1 is technically viable. The connection assessment did not identify any system performance issues in the pre-Project or post-Project scenarios.

It is recommended to proceed with the Project using Alternative 1 as the preferred option to respond to the DFO’s request for system access service. Alternative 1 involves upgrading the existing Pinedale 207S substation, including adding one 138/25 kV transformer, one 138 kV circuit breaker, one 25 kV feeder circuit breaker and associated equipment.

It is recommended that the 138/25 kV transformer at Pinedale 207S substation have a transformation capability of 25 MVA to match the transformation capability of the existing Pinedale 207S substation transformer. Adding a 25 MVA 138/25 kV transformer at the Pinedale 207S substation will meet the DFO’s requested Rate DTS contract capacity increase and the DFO’s distribution system planning criteria for electrical load restoration.

Attachment A

Pre-Project Load Flow Diagrams

October 30, 2017Final

A.1 Load Flow Diagram

The Pre-Project load flow diagrams for Category A and B contingencies are provided in this section. The following table presents the list of the load flow diagrams. Please note that the Welwood #2 generator is turned off for the analyzed cases.

Table A-1: List of Pre-Project load flow diagrams

Scenario Load flow diagram Figure number

2018SP

N-G-0, System Normal Condition A-1-1

N-G-1, Loss of 58ST1 A-1-2


N-G-1, Loss of 890L A-1-4

N-G-1, Loss of 1150L A-1-5



N-G-1, Loss of 207S T1 A-1-8

2018WP

N-G -0, System Normal (N-G) A-2-1




N-G-1, Loss of 1150L A-2-5



N-G-1, Loss of 207S T1 A-2-8

P1903: 2018SP Pre Project

Fortis East Yellowhead Area Capacity and Reliability

973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP PRE-PROJECT 1903 AESON-G-0, SYSTEM NORMAL CONDITIONFIG A-1-1TUE, AUG 15 2017 14:58

207ST1

744L

Bus - Voltage (kV/pu)Branch - MW/MvarEquipment - MW/Mvar100.0%Rate A1.105OV 0.898UVkV: >0.000



973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP PRE-PROJECT 1903 AESON-G-1, LOSS OF 58ST1FIG A-1-2TUE, AUG 15 2017 14:58

207ST1

744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP PRE-PROJECT 1903 AESON-G-1, LOSS OF 58ST2FIG A-1-3TUE, AUG 15 2017 14:58

207ST1

744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP PRE-PROJECT 1903 AESON-G-1, LOSS OF 890LFIG A-1-4TUE, AUG 15 2017 14:59

207ST1

744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L


207ST1

744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP PRE-PROJECT 1903 AESON-G-1, LOSS OF 207S T1FIG A-1-8TUE, AUG 15 2017 14:59

207ST1

744L


P1903: 2018WP Pre Project


973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP PRE-PROJECT 1903 AESON-G-0, SYSTEM NORMAL CONDITIONFIG A-2-1TUE, AUG 15 2017 14:59

207ST1744L

Bus - Voltage (kV/pu)Branch - MW/MvarEquipment - MW/Mvar100.0%Rate B1.105OV 0.898UVkV: >0.000



973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP PRE-PROJECT 1903 AESON-G-1, LOSS OF 58ST1FIG A-2-2TUE, AUG 15 2017 14:59

207ST1744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP PRE-PROJECT 1903 AESON-G-1, LOSS OF 58ST2FIG A-2-3TUE, AUG 15 2017 14:59

207ST1744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP PRE-PROJECT 1903 AESON-G-1, LOSS OF 890LFIG A-2-4TUE, AUG 15 2017 14:59

207ST1744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L


207ST1744L




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP PRE-PROJECT 1903 AESON-G-1, LOSS OF 207S T1FIG A-2-8TUE, AUG 15 2017 14:59

207ST1744L


Transmission Project Delivery

R[x]

1

Public

R2-2012-03-21

Attachment B

Post-Project Load Flow Diagrams

October 30, 2017Final

B.1 Load Flow Diagram

The post-Project load flow diagrams for Category A and B contingencies are provided in this section. The following table presents the list of the load flow diagrams. Please note that the Welwood #2 generator is turned off for the analyzed cases.

Table B-1: List of Post-Project load flow diagrams

Scenario Load flow diagram Page number

N-G-0, System Normal (N-G)

N-G-1, Loss of 58ST1


2018SP N-G-1, Loss of 890L

N-G-1, Loss of 1150L

N-G-1, Loss of 974L

N-G-1, Loss of 973L

N-G-1, Loss of 207S T2

N-G -0, System Normal (N-G)



N-G-1, Loss of 890L

2018WP N-G-1, Loss of 1150L

N-G-1, Loss of 974L

N-G-1, Loss of 973L

N-G-1, Loss of 207S T2

P1903: 2018SP Post Project


973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP POST-PROJECT 1903 AESON-G-0, SYSTEM NORMAL CONDITIONFIG B-1-1TUE, AUG 15 2017 16:57

207ST2

744L

P1903 - Alt 1

207ST1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP POST-PROJECT 1903 AESON-G-1, LOSS OF 58ST1FIG B-1-2TUE, AUG 15 2017 16:57

207ST2

744L

P1903 - Alt 1

207ST1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP POST-PROJECT 1903 AESON-G-1, LOSS OF 58ST2FIG B-1-3TUE, AUG 15 2017 16:57

207ST2

744L

P1903 - Alt 1

207ST1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP POST-PROJECT 1903 AESON-G-1, LOSS OF 890LFIG B-1-4TUE, AUG 15 2017 16:57

207ST2

744L

P1903 - Alt 1

207ST1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L


207ST2

744L

P1903 - Alt 1

207ST1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018SP POST-PROJECT 1903 AESON-G-1, LOSS OF 207S T2FIG B-1-8TUE, AUG 15 2017 16:57

207ST2

744L

P1903 - Alt 1

207ST1


P1903: 2018WP Post Project


973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP POST-PROJECT 1903 AESON-G-0, SYSTEM NORMAL CONDITIONFIG B-2-1TUE, AUG 15 2017 16:57

744L

207ST2

207ST1

P1903 - Alt 1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP POST-PROJECT 1903 AESON-G-1, LOSS OF 58ST1FIG B-2-2TUE, AUG 15 2017 16:58

744L

207ST2

207ST1

P1903 - Alt 1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP POST-PROJECT 1903 AESON-G-1, LOSS OF 58ST2FIG B-2-3TUE, AUG 15 2017 16:58

744L

207ST2

207ST1

P1903 - Alt 1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP POST-PROJECT 1903 AESON-G-1, LOSS OF 890LFIG B-2-4TUE, AUG 15 2017 16:58

744L

207ST2

207ST1

P1903 - Alt 1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L


744L

207ST2

207ST1

P1903 - Alt 1




973L

974L

890L

1150L

58ST1

58ST2

202L

740L

847L

854L

671L

740L

2018WP POST-PROJECT 1903 AESON-G-1, LOSS OF 207S T2FIG B-2-8TUE, AUG 15 2017 16:58

744L

207ST2

207ST1

P1903 - Alt 1


Attachment C

Post-Project Voltage Stability Diagrams

C.1 Post-Project Voltage Stability Diagrams

The voltage stability analysis was completed for the post-Project winter peak scenario (2018WP). The P-V graphs for the worst contingnecies are provided below.

Figure C-1 shows the P-V curve for Edson transformer 58T1 or 58T2, 890L,1150L, 974L and 973L contingencies in 2018WP post-Project.

Figure C- 1: P-V Curves for Post-Project

(a) Edson Transformer T1 or T2 Contingency

(b) 890L (Bickerdike 39S to Pinedale 207S) Contingency

(c) 1150L (Bickerdike 39S to Hornbeck 345S) Contingency

(d) 973L (Bickerdike 39S to Sundance 310P) Contingency

(e) 974L (Bickerdike 39S to Sundance 310P) Contingency

Attachment B.pdfB-1-1 - 2018SP POST-PROJECT 1903 AESO, N-G-0, System Normal ConditionB-1-2 - 2018SP POST-PROJECT 1903 AESO, N-G-1, Loss of 58ST1B-1-3 - 2018SP POST-PROJECT 1903 AESO, N-G-1, Loss of 58ST2B-1-4 - 2018SP POST-PROJECT 1903 AESO, N-G-1, Loss of 890LB-1-5 - 2018SP POST-PROJECT 1903 AESO, N-G-1, Loss of 1150LB-1-6 - 2018SP POST-PROJECT 1903 AESO, N-G-1, Loss of 974LB-1-7 - 2018SP POST-PROJECT 1903 AESO, N-G-1, Loss of 973LB-1-8 - 2018SP POST-PROJECT 1903 AESO, N-G-1, Loss of 207S T1B-2-1 - 2018WP POST-PROJECT 1903 AESO, N-G-0, System Normal ConditionB-2-2 - 2018WP POST-PROJECT 1903 AESO, N-G-1, Loss of 58ST1B-2-3 - 2018WP POST-PROJECT 1903 AESO, N-G-1, Loss of 58ST2B-2-4 - 2018WP POST-PROJECT 1903 AESO, N-G-1, Loss of 890LB-2-5 - 2018WP POST-PROJECT 1903 AESO, N-G-1, Loss of 1150LB-2-6 - 2018WP POST-PROJECT 1903 AESO, N-G-1, Loss of 974LB-2-7 - 2018WP POST-PROJECT 1903 AESO, N-G-1, Loss of 973LB-2-8 - 2018WP POST-PROJECT 1903 AESO, N-G-1, Loss of 207S T1