Connection Engineering Study Report for AUC Application: AESO Project # 1674

APPENDIX A CONNECTION ASSESSMENT

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Executive Summary Project Overview FortisAlberta Inc. (FortisAlberta) submitted a System Access Service Request (SASR) to the Alberta Electric System Operator (AESO) to increase the Rate Demand Transmission Service (DTS) from 17.4 MW to 21.1 MW at the existing Cooking Lake 522S substation in the Edmonton area (the Project). The requested In-Service Date (ISD) for the Project is July 1, 2017. Existing System The Project is located in the AESO planning area of Edmonton (Area 60) as part of the AESO Edmonton Region. The existing constraints in Edmonton Region are managed in accordance with Section 302.1 of the ISO Rules, Real Time Transmission Constraint Management (TCM Rule). The Cooking Lake 522S substation is connected to the 138 kv transmission system south and southeast of the City of Edmonton which is closely tied to the 138 kv system in the AESO Wetaskiwin Planning Area (Area 31). The Cooking Lake 522S substation load is fed primarily from the following four sources. 1. East Edmonton 38S 240/138 kv substation which is connected to Bretona 45S and Nisku 149S substations by 138 kv transmission lines; 2. Transmission line 174L connecting the North Holden 395S substation to the Bardo 197S substation; 3. Bigstone 86S substation; and 4. Transmission line 739L from the Acheson 305S substation to the Devon 14S substation. Study Summary Study Area for the Project The study area for the Project consists of the Edmonton and Wetaskiwin planning areas, including the tie lines connecting two planning areas to the Alberta Interconnected Electrical System (Study Area). All transmission facilities within the Study Area were studied and monitored for violations of the Reliability Criteria (further described in Section 2.1). The two 138 kv transmission lines connecting the Study Area to the rest of the AIES (namely, transmission lines 739L and 174L) were also studied and monitored to identify any violations of the Reliability Criteria. Studies Performed for the Project Load flow analysis was performed for the 2017 summer peak (SP) and winter peak (WP) pre- Project and post-project scenarios, with the 2017 AIES topology in the Study Area to determine the Project impact on the Alberta Interconnected Electrical System (AIES). Voltage stability RP-05-1674 Page 1 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 analysis was performed for the 2017 WP post-project scenario to identify violations, if any, of the voltage stability criteria. Results of the pre-project Studies The pre-project study results and applicable mitigation measures are summarized below and detailed in Table E-1. 2017 SP Category A (N-G-0) conditions No Reliability Criteria violations were observed under Category A conditions for the 2017 SP scenario. Category B (N-G-1) conditions No voltage criteria violations were identified under Category B conditions for the 2017 SP scenario. Several transmission line flows above summer continuous ratings were observed; these are existing conditions and currently managed by real time operational practices. Voltage deviations observed at the St. Albert 99S substation are also a known condition managed by real time operational practices. The approved South and West of Edmonton Area Transmission Development (SWEATD) 1, which includes reconfiguring the 138 kv system east of the City of Edmonton, is planned to alleviate thermal loadings above summer continuous ratings and voltage deviations by Q4 2017. 2017 WP Category A (N-G-0) conditions No Reliability Criteria violations were observed under Category A conditions for the 2017 WP scenario. Category B (N-G-1) conditions No Reliability Criteria violations were observed under Category B conditions for the 2017 WP scenario. Voltage deviations observed at the St. Albert 99S substation are currently managed by real time operational practices and will be mitigated by SWEATD, planned for Q4 2017. Table E-1 Overview of Pre-Project Study Results Condition Scenario Results Mitigation measure Contingency Result Category A 2017 SP -- -- -- 2017 WP -- -- -- Category B 2017 SP Loss of the 240/138kV transformer at Bigstone Thermal loading above continuous ratings Currently managed by real time operational practices 1 The South and West Edmonton Area Transmission Reinforcement Needs Identification Document, approved by the Alberta Utilities Commission under Approval No. U2014-183, is available at: http://www.aeso.ca/downloads/r_south_and_west_edmonton_area_transmission_reinforcement_needs_identification_document.pdf. RP-05-1674 Page 2 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Condition Scenario Results Mitigation measure Contingency 86S substation 2 Result below short-term rating on the 138 kv transmission line Loss of the 138 kv transmission line 780L Loss of the 138 kv transmission line 604L Loss of the 138 kv transmission line 739L Loss of the 138 kv transmission line 1045L Thermal loading above continuous ratings below short-term rating on the 138 kv transmission line 780L Thermal loading above continuous ratings below short-term rating on the 138 kv transmission line Thermal criteria violation on the 138 kv transmission line Thermal loading above continuous ratings below short-term rating on the 138 kv transmission line Thermal loading above continuous ratings below short-term rating on the 240 kv transmission line 905L Currently managed by real time operational practices Currently managed by real time operational practices Currently managed by real time operational practices Currently managed by real time operational practices Currently managed by real time operational practices 2017 WP -- -- -- Connection alternatives examined for the Project FortisAlberta examined and ruled out the use of distribution-based solutions to serve the additional load. This connection engineering study report (Report) will examine the following transmission alternatives to serve the requested 21.1 MW DTS capacity at the Cooking Lake 522S substation. Alternative 1 Upgrade the Cooking Lake 522S Substation Add a second 138/25 kv transformer, rated at 25/33/42 MVA, one 25 kv feeder breaker, and associated equipment at the Cooking Lake 522S substation. 2 While the loss of the 240/138kV transformer at Bigstone 86S substation is considered a Category B (N-G-1) event, this event would in fact result in the simultaneous loss of the 240 kv bus, the 240 kv transmission lines 914L (to the Gaetz 87S substation) and 914L (to the Ellerslie 89S), the 138 kv bus and the 138 kv transmission lines 805L (to Pigeon 964S) and 803L/804L (to Wetaskiwin 40S) due to the Bigstone 240 kv/138 kv bus configuration. RP-05-1674 Page 3 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Alternative 2 Upgrades at the Blackmud 155S Substation Install a new 25 kv feeder breaker at the Blackmud 155S substation. Connection alternatives selected for further examination Alternative 1 was selected for further study. In its Need for Development report (DFO Report) 3, FortisAlberta, the distribution facility owner, concluded that: Alternative 1 would address the distribution reliability and capacity concerns for the distribution system connected to the Cooking Lake 522S substation; and Alternative 2 would also address the capacity concerns but not the distribution reliability issues at the Cooking Lake 522S substation due to insufficient transformation capacity at adjacent substations. Therefore, Alternative 2 is not a technically acceptable solution and was not selected for further studies. Results of the post-project studies The post-project study results are summarized below and detailed in Table E-2.The noted thermal violations and voltage deviations will be managed by real time operational procedures until completion of the SWEATD, planned for Q4 2017. 2017 SP Category A (N-G-0) conditions No Reliability Criteria violations were observed under Category A conditions for the 2017 SP scenario. Category B (N-G-1) conditions No voltage criteria violations were identified under Category B conditions for the 2017 SP scenario. The same pre-project Category B transmission line flows above summer continuous ratings were observed; these are existing conditions and currently managed by real time operational practices. The same pre-project Category B voltage deviations at the St. Albert 99S substation were observed under the post-project 2017 SP scenario. The Project had no material impact on the system performance. 2017 WP Category A (N-G-0) conditions No Reliability Criteria violations were observed under Category A conditions for the 2017 WP scenario. 3 FortisAlberta Need for Development Cooking Lake 522S Upgrade, dated June 24, 2015 is filed under separate cover. RP-05-1674 Page 4 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Category B (N-G-1) conditions No Reliability Criteria violations were observed under Category B conditions for the 2017 WP scenario. The pre-project voltage deviations at the St. Albert 99S substation were also observed post- Project. The Project had no material impact on the system performance. Table E-2 Overview of Post-Project Study Results Condition Scenario Results Mitigation measure Contingency Result Category A 2017 SP -- -- -- 2017 WP -- -- -- Loss of the 240/138kV transformer at Bigstone 86S substation 4 Thermal loading above continuous ratings below short-term rating on the 138 kv transmission line Thermal loading above continuous ratings below short-term rating on the 138 kv transmission line 780L Currently managed by real time operational practices Currently managed by real time operational practices Category B 2017 SP Loss of the 138 kv transmission line 780L Thermal loading above continuous ratings below short-term rating on the 138 kv transmission line Currently managed by real time operational practices Loss of the 138 kv transmission line 604L Thermal criteria violation on the 138 kv transmission line Currently managed by real time operational practices Loss of the 138 kv transmission line 739L Thermal loading above continuous ratings below short-term rating on the 138 kv transmission line Currently managed by real time operational practices Loss of the 138 kv transmission line 1045L Thermal loading above continuous ratings below short-term rating on the 240 kv transmission line 905L Currently managed by real time operational practices 2017 WP -- -- -- 4 While the loss of the 240/138kV transformer at Bigstone 86S substation is considered a Category B (N-G-1) event, this event would in fact result in the simultaneous loss of the 240 kv bus, the 240 kv transmission lines 914L (to the Gaetz 87S substation) and 914L (to the Ellerslie 89S), the 138 kv lines 805L (to Pigeon 964S) and 803L/804L (to Wetaskiwin 40S) due to the Bigstone 240 kv/138 kv bus configuration. RP-05-1674 Page 5 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Mitigation Measures As indicated in Table E-1, Reliability Criteria violations that were identified in the pre-project studies are currently managed by real time operational practices. As indicated in Table E-2, Reliability Criteria violations that were identified in the post-project studies will continue to be managed by real time operational practices. These observed N-1 thermal loadings above continuous ratings will be addressed with the completion of the SWEATD project. Recommendation The studies demonstrate that the connection of the Project would not adversely impact the performance of the AIES. Consequently, the AESO recommends proceeding with the Project by adding a second transformer at the Cooking Lake 522S substation. RP-05-1674 Page 6 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Contents Executive Summary... 1 1. Introduction... 10 1.1. Project... 10 1.1.1. Project Overview... 10 1.1.2. Generation Component... 10 1.2. Study Scope... 10 1.2.1. Study Objectives... 10 1.2.2. Study Area... 11 1.2.3. Studies Performed... 13 1.3. Report Overview... 13 2. Criteria, System Data, and Study Assumptions... 14 2.1. Criteria, Standards, and Requirements... 14 2.1.1. Transmission Planning Standards and Reliability Criteria... 14 2.1.2. AESO Rules... 15 2.2. Study Scenarios... 15 2.3. Load and Generation Assumptions... 16 2.3.1. Load Assumptions... 16 2.3.2. Generation Assumptions... 16 2.3.3. Intertie Flow Assumptions... 17 2.4. System Projects... 17 2.5. Customer Connection Projects... 17 2.6. Facility Ratings and Shunt Elements... 18 2.7. Voltage Profile Assumptions... 19 3. Study Methodology... 21 3.1. Connection Studies Carried Out... 21 3.2. Load Flow Analysis... 21 3.2.1. Contingencies Studied... 21 3.3. Voltage Stability (PV) Analysis... 22 3.3.1. Contingencies Studied... 22 4. Pre-Project System Assessment... 23 4.1. Pre-Project Load Flow Analysis... 23 4.1.1. 2017 Summer Peak 2017 SP, Scenario 1... 23 4.1.2. 2017 Winter Peak 2017 WP, Scenario 2... 24 5. Connection Alternatives... 26. Overview... 26 5.2. Connection Alternatives Identified... 26 5.3. Connection Alternatives Selected for Further Studies... 26 5.4. Connection Alternatives Not Selected for Further Studies... 26 6. Technical Analysis of the Connection Alternatives... 27 6.1. Load Flow... 27 6.1.1. Alternative 1... 27 6.1.1.1. 2017 Summer Peak 2017SP, Scenario 3... 27 6.1.1.2. 2017 Winter Peak 2017WP, Scenario 4... 28 6.2. Voltage Stability... 29 RP-05-1674 Page 7 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 6.2.1. Alternative 1... 29 6.2.1.1. 2017 Winter Peak 2017WP, Scenario 4... 29 7. Mitigation Measures... 30 8. Project Interdependencies... 31 9. Summary and Conclusion... 32 RP-05-1674 Page 8 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Attachments Attachment A Pre-Project Load Flow Diagrams (Scenarios 1 to 2) Attachment B Post-Project Load Flow Diagrams (Scenarios 1 to 2) Attachment C Alternative 1: Voltage Stability Diagrams (Scenarios 4) Figures Figure 1-1: Existing Study Area Transmission System... 11 Figure 1-2: Edmonton Region Transmission System Future Configuration... 13 Tables Table 1.2-1: Summary of System Projects in the Study Area... 12 Table 2.1-1: Post Contingency Voltage Deviation Guidelines... 15 Table 2.2-1: List of the Connection Study Scenarios... 15 Table 2.3-1: Forecast Area Load (2014 LTO at Edmonton Region Peak)... 16 Table 2.3-2: Local Generation (MW) in the Study Cases... 17 Table 2.5-1: Summary of Customer Connection Assumptions... 17 Table 2.6-1: Summary of Transmission Line Ratings in the Study Area (MVA on 138 kv Base)... 18 Table 2.6-2: Summary of Transformer Ratings in the Study Area... 19 Table 2.6-3: Summary of Shunt Elements in the Study Area... 19 Table 2.7-1: Operating Voltages at Key Nodes in the Study Area and Vicinity... 20 Table 3.1-1: Summary of Studies Performed... 21 Table 4.1-1: Summary of System Performance (Element Loading) [2017SP Pre-Project N-G-1 Line Loading Above Continuous rating]... 23 Table 4.1-2: Summary of System Performance (Voltage Deviation) [2017SP Pre-Project N-G-1]... 24 Table 4.1-3: Summary of System Performance (Voltage Deviation) [2017WP Pre-Project N-G-1]... 25 Table 6.1-1: Summary of System Performance (Element Loading) [Scenario 3-2017 SP Post-Project N-G-1 Line Loading Above Continuous Rating]... 27 Table 6.1-2: Summary of System Performance for Scenario 3 (Voltage Deviation)... 28 Table 6.1-3: Summary of System Performance for Scenario 4 (Voltage Deviation)... 29 Table 6.2-1: Scenario 4: 2017 WP Voltage stability analysis results (Minimum transfer = 16.7 MW)... 29 RP-05-1674 Page 9 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 1. Introduction FortisAlberta has requested a 3.7 MW increase to its Cooking Lake 522S substation rate Demand Transmission Service (DTS). This Report recommends the connection alternative to serve the requested increase and presents the results of the study conducted to analyze the Project connection impact on the performance of the AIES. 1.1. Project 1.1.1. Project Overview FortisAlberta Incorporated (FortisAlberta) has submitted a System Access Service Request (SASR) to the Alberta Electric System Operator (AESO) for increasing the Demand Transmission Service (DTS) from the existing value of 17.4 MW to 21.1 MW by July 2017 at the existing Cooking Lake 522S substation. The requested In-Service Date (ISD) for the Project is July 1, 2017. The existing DTS at the Cooking Lake 522S substation is 17.4 MW. The requested load addition is 3.7 MW by July 2017. The load will be studied assuming a 0.9 power factor (pf) lagging. Load Type: Comprised of farm, rural residential, small commercial and light industrial loads. FortisAlberta s SASR did not indicate plans for a future load increase at the Cooking Lake 522S substation. 1.1.2. 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: 1. Assess the impact of the Project connection on the AIES. 2. Examine the Project connection alternatives. 3. Recommend the Project connection alternative and any mitigation measures to address system performance concerns, if any, to enable the reliable integration of the Project into the AIES. RP-05-1674 Page 10 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 1.2.2. Study Area 1.2.2.1. Study Area Description The Project is located in the AESO Edmonton Planning Area (Area 60) which forms part of the Edmonton Region. The Study Area consists of the Edmonton and Wetaskiwin Planning Areas, including the tie lines connecting two planning areas to the rest of the Alberta Interconnected Electrical System AIES. All transmission facilities within the two planning areas were studied and monitored for violations of the Reliability Criteria, further described in Section 2.1.1. The two 138 kv transmission lines connecting the Study Area to the rest of the AIES, namely transmission lines 739L and 174L, were also studied and monitored to identify any violations of the Reliability Criteria. Figure 1-1: Existing Study Area Transmission System RP-05-1674 Page 11 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 1.2.2.2. Existing Constraints The existing Remedial Action Scheme (RAS), Bigstone (T86S) Reverse Power/Undervoltage Scheme (#121), is used to avoid power flow from the 138 kv to 240 kv bus at the Bigstone 86S substation to mitigate potential thermal overloads in neighbouring 138 kv transmission systems. The existing constraints in Edmonton Region are managed in accordance with the TCM Rule. 1.2.2.3. AESO Long-Term Transmission Plans (LTP) Figure 1-2 shows a schematic representation of the bulk transmission system expected in Q4 2017 in the Edmonton Region after completion of the SWEATD. The SWEATD, described in Table 1.2-1, is not expected to be in service until Q4 2017 and therefore was not modeled in the study scenarios presented in this Report. Table 1.2-1: Summary of System Projects in the Study Area Project Name Project Description Projected in-service date Status in Study NID filed; Energization 1 - Harry Smith Sub SWEATD South and West Edmonton Area Transmission Development Energization 2 - New Saunders Lake 240/138kV Substation; re-terminate 910L, 914L, 780L & 858L at Saunders Lake; build lines between Nisku & proposed Saunders Lake; and reconfiguration of affected substations. Energization 3 - New 138kV Lines from 780L to Cooking Lake & 174L; and reconfiguration of affected substations Q4 2017 Not included Energization 4 - Open 133L from Wabamun to 234L tap 5 - New Capacitor Bank at Leduc 325S Energization RP-05-1674 Page 12 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Figure 1-2: Edmonton Region Transmission System Future Configuration 1.2.3. Studies Performed The following studies were performed for the pre-project analysis: Power Flow analysis (Categories A and B for 2017 SP and 2017 WP study scenarios) The following studies were performed for the post-project analysis: Power Flow analysis (Categories A and B for 2017 SP and 2017 WP study scenarios) Voltage Stability analysis (Category A and B for 2017 WP study scenario) 1.3. Report Overview The Executive Summary provides a high-level summary of the study and its conclusions. Section 1 introduces this Report. Section 2 describes the reliability criteria, system data, and other study assumptions used in this study. Section 3 describes the methodology used for this study. Section 4 discusses the pre-project assessment of the system. Section 5 presents all the connection alternatives contemplated. Section 6 provides a technical analysis of the connection alternatives considered for further study. Section 7 identifies any interdependencies this project may have. Section 8 presents the summary and conclusions of this study. RP-05-1674 Page 13 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 2. Criteria, System Data, and Study Assumptions 2.1. Criteria, Standards, and Requirements 2.1.1. Transmission Planning 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, Reliability Criteria) 5 will be applied to evaluate system performance under Category A system conditions (i.e., all elements in-service) and following Category B (i.e., single element outage) and Category C5 contingencies (i.e., double circuit common tower outage), prior to and following the studied alternatives. Below is a summary of Category A, Category B and Category C5 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. 5 Filed under separate cover RP-05-1674 Page 14 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 For Category A conditions: Voltage range under normal operating condition should follow the AESO Information Document ID# 2010-007RS. For the busses not listed in ID#2010-007RS, Table 2-1 in the Transmission Planning Criteria Basis and Assumptions applies. For Category B conditions: The extreme voltage range values per Table 2-1 in the Transmission Planning Criteria Basis and Assumptions. Desired post-contingency voltage change limits for three defined post event timeframes as provided in Table 2.1-1. Table 2.1-1: Post Contingency Voltage Deviation Guidelines Parameter and reference point Voltage deviation from steady state at POD low voltage bus. Post Transient (up to 30 sec) Time Period Post Auto Control (30 sec to 5 min) Post Manual Control (Steady State) ±10% ±7% ±5% 2.1.2. AESO Rules The AESO Voltage Control Practice ID # 2010-007RS will be applied to establish precontingency voltage profiles in the Study Area. The TCM Rule will be followed in setting up the study scenarios and assessment of the impact of the Project connection. In addition, due regard will be given to the AESO s Connection Study Requirements and the AESO s Generation and Load Interconnection Standard. The Reliability Criteria is the basis for planning the AIES. The transmission system will normally be designed to meet or exceed the Reliability Criteria under credible worst-case loading and generation conditions. 2.2. Study Scenarios Table 2.2-1 provides a list of the study scenarios. Scenarios 1 and 2 are the pre-project scenarios for 2017 SP and 2017 WP; scenarios 3 and 4 are the post-project scenarios for 2017 SP and 2017 WP with the requested 3.7 MW DTS increase at the Cooking Lake 522S substation. A power factor of 0.9 lagging was used for the new Project load. Table 2.2-1: List of the Connection Study Scenarios Scenario Year/Season Load Condition Cooking Lake 522S Load (MW) 1 2017 SP Pre-Project 17.4 2 2017 WP Pre-Project 17.4 3 2017 SP Post Project 21.1 4 2017 WP Post-Project 21.1 RP-05-1674 Page 15 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Scenario Year/Season Load Condition Cooking Lake 522S Load (MW) 5 2025 WP Post-Project 21.1 2.3. Load and Generation Assumptions 2.3.1. Load Assumptions The Study Area and Region load forecasts used for this connection study is shown in Table 2.3-1 and is from the AESO 2014 Long-term Outlook (2014 LTO). In this study the active power to reactive power ratio in the base case scenarios was maintained when developing the study scenarios. Table 2.3-1: Forecast Area Load (2014 LTO at Edmonton Region Peak) Area or Region Name and Season Forecast Peak Load (MW) 2017 Wetaskiwin (Area 31) Wabamun (Area 40) Edmonton (Area 60) Edmonton Region (Areas 31, 40 and 60) AIL w/o Losses SP 140 WP 161 SP 176 WP 219 SP 1889 WP 1933 SP 2206 WP 2313 SP 11440 WP 12796 2.3.2. Generation Assumptions The generation conditions for this connection study are described in Table 2.3-2. The study identified the Battle River 5 Generator at Battle River 757S substation in the Alliance/Battle River area as the critical generator and it is turned off to represent the N-G study condition for all analyses. RP-05-1674 Page 16 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Table 2.3-2: Local Generation (MW) in the Study Cases 2017 SP 2017 WP Plant Name Bus Number Area PMax (MW) Unit Net Generation 6 (MW) Unit Net Generation 6 (MW) Cloverbar GT1 255161 60 48 0 0 Cloverbar GT2 26516 60 101 0 34 Cloverbar GT3 27516 60 101 0 49 U of A ST1 25352 60 54 17 19 Total 304 17 102 2.3.3. Intertie Flow Assumptions The dispatch level of the British Columbia, Montana Alberta Tie Line and Saskatchewan interties are deemed to be too far away to have an effect on the assessment of the proposed connection. The flows in the Study Area are not influenced by the AIES HVDC facilities. As a result, the intertie and HVDC assumptions are kept consistent with the AESO planning base cases and are not adjusted for this study. 2.4. System Projects No transmission system long-term projects were included in the study cases. The SWEATD, described in Section 1.2.2.3, is not expected to be in service until Q4 2017 and therefore was not modeled in the study scenarios presented in this Report. 2.5. Customer Connection Projects The list of the customer projects included in the study is shown in Table 2.5-1 Table 2.5-1: Summary of Customer Connection Assumptions Planning Area Queue Position* Planned In- Service Date Project Name Project # Gen (MW) Load (MW) Included/Excluded from Studies 60 41 Feb 1, 2019 60 48 2020~2021 Fortis New Anthony Henday Substation Genesee Generating Units 4 (G4) and 5 (G5) 1442 0.0 21.0 Excluded 1440 900.0 0.0 Excluded 31 50 May 14, 2016 Fortis Cargill Camrose Canola 1578 0.0 0.0 Included 6 Unit net Generation refers to Gross Generating unit MW output less Unit Service Load. RP-05-1674 Page 17 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Planning Area Queue Position* Planned In- Service Date Project Name Project # Gen (MW) Load (MW) Included/Excluded from Studies Plant 60 54 Oct 14, 2016 60 63 Jul 6, 2016 60 72 Jun 24, 2016 60 75 Nov 1, 2016 60 89 Jun 24, 2016 60 91 Apr 1, 2017 Imperial Oil Strathcona Refinery Cogeneration Project Fortis Leduc Transformer and Breakers Addition ASTC Power Sundance 3 Uprate Fortis Broadmoor 420S Upgrade EPCOR Dome Substation D84 Feeder Reactor Addition Fortis Cooking Lake 522A Capacity Increase 1519 0.0 0.0 Included 1574 0.0 19.3 Included 1600 15.0 0.0 Included 1597 0.0 32.7 Included 1678 0.0 75.0 Included 1674 0.0 3.7 Included * Per the AESO Connection Queue posted in April 2016. Project 1442 and Project 1440 are not planned to be in service until after the Project and so were excluded from the study. 2.6. Facility Ratings and Shunt Elements The transmission facilities owner (TFO) provided the ratings of the existing transmission lines (Table 2.6-1) and the existing transformers (Table 2.6-2) in the Study Area. Line ID Table 2.6-1: Summary of Transmission Line Ratings in the Study Area (MVA on 138 kv Base) Line Description Voltage Class (kv) Nominal Rating (MVA) Short-term 7 Rating (MVA) Summer Winter Summer Winter 897L East Edmonton 38S - Bretona 45S 138 8 9 94 99 874L Bretona 45S - Cooking Lake 522S 138 8 9 94 99 174L Cooking Lake 522S - Bardo 197S 138 8 9 94 99 174L Bardo 197S - North Holden 395S 138 8 9 94 99 701L North Holden 395S - Strome 223S 138 119.0 146.0 131 161 730L Bardo 197S - Kingman Tap 138 86.0 91.1 95 100 730L Kingman Tap - East Camrose 285S 138 8 9 94 99 729L East Camrose 285S - Ervick 542S 138 8 9 94 99 729L Ervick 542S - Trueweld Tap 138 8 9 94 99 729L Trueweld Tap - Wetaskiwin 40S 138 98.0 131.9 108 145 7 When line loading in post Category B contingency is observed to exceed nominal rating and is less than the Short-term (emergency) rating, it is assumed that AESO and TFO operating practices can manage the constraint within the time requirements of TFO short time (emergency) rating. RP-05-1674 Page 18 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Line ID Line Description Voltage Class (kv) Nominal Rating (MVA) Short-term 7 Rating (MVA) Summer Winter Summer Winter 858L Wetaskiwin 40S - Nisku 149S 138 121.9 147.0 134 162 780L East Edmonton 38S - Nisku 149S 138 98.0 131.9 108 145 Table 2.6-2: Summary of Transformer Ratings in the Study Area Substation Name and Number Transformer ID Transformer Voltages (kv) MVA Rating East Edmonton 38S 38ST1 240/138 337 38ST4 240/138 337 Bigstone 86S 86ST1 240/138 200 The details of shunt elements in the Study Area are given in Table 2.6-3. Table 2.6-3: Summary of Shunt Elements in the Study Area Capacitors Reactors Substation Name and Number Voltage Class (kv) Number of Switched Shunt Blocks Total at Nominal Voltage (MVAr) Status in Study (on or off) 2017 SP 2017 WP Number of Switched Shunt Blocks Total at Nominal Voltage (MVAr) Status in Study (on or off) 2017 SP 2017 WP (MVAr) (MVAr) (MVAr) (MVAr) East Edmonton 38S 138 2 x 48.91 MVAr 97.82 97.82 (on) 97.82 (on) - - - - Nisku 138 1 x 30 MVAr 30 30 (on) 30 (on) - - - - 2.7. Voltage Profile Assumptions The AESO Voltage Control Practice ID # 2010-007RS is used to establish normal system (i.e. pre-contingency) voltage profiles for key area busses prior to commencing any studies. Table 2-1 of the Transmission Planning Criteria Basis and Assumptions applies for all the busses not included in the ID 2010-007RS. These voltages were utilized to set the voltage profile for the study base cases prior to load flow analysis. A list of operating voltages for the key buses in the Study Area and its vicinity are listed in Table 2.7-1. RP-05-1674 Page 19 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Table 2.7-1: Operating Voltages at Key Nodes in the Study Area and Vicinity AESO ID 2010-007RS Bus No. and Name Nominal Voltage (kv) Minimum Operating Limit (kv) Desired Range (kv) Maximum Operating Limit (kv) 136 E EDMON4 240 240 240 253 255 89 E EDMON7 138 139 139 144 145 81 BIGSTON4 240 N/A 8 243 253 260 374 BIGSTON7 138 135 141 145 145 359 ACHESON 138 138 138-144 145 8 The 240 kv system is operated as required to maintain the 138 kv voltage within operating limits. RP-05-1674 Page 20 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 3. Study Methodology 3.1. Connection Studies Carried Out The studies carried out for this connection study are identified in Table 3.1-1. The critical generator identified for this study was Battle River 5 Generator unit at Battle River 757S substation. Scenario and Condition Table 3.1-1: Summary of Studies Performed Project 1674 The Cooking Lake 522S substation Load (MW) Generation (MW) System Conditions Load Flow Voltage Stability 1 2017 SP Pre-project 17.4 0 Category A and Category B Included - 2 2017 WP Pre-Project 17.4 0 Category A and Category B Included - 3 2017 SP Post-Project 21.1 0 Category A and Category B Included - 4 2017 WP Post-Project 21.1 0 Category A and Category B Included Included 5 2025 WP Post-Project 21.1 0 Category A - - 3.2. Load Flow Analysis Load flow analysis will be completed for all study scenarios to identify any thermal or transmission voltage violations as per the Reliability Criteria. Transformer tap and switched shunt reactive compensation devices such as shunt capacitors and reactors will be locked and continuous shunt devices will be enabled when performing Category B load flow analysis. POD low voltage bus deviations will also be assessed by first locking all tap changers and area capacitors to identify any post-transient voltage deviations above 10%. Tap changers will then be allowed to adjust, while shunt reactive compensating devices remained locked to determine if any voltage deviations above 7% would occur in the area. Once all taps and shunt reactive compensating devices have been adjusted, voltage deviations above 5% will be reported, for both the pre-project and post-project networks. 3.2.1. Contingencies Studied Load flow analysis was performed for the Category A condition and all Category B contingencies in the Edmonton (Area 60) and Wetaskiwin (Area 31) planning areas, including ties to surrounding areas for all pre- and post-project scenarios. RP-05-1674 Page 21 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 3.3. Voltage Stability (PV) Analysis The objective of the Power-Voltage (PV) curve is to determine the ability of the network to maintain voltage stability at all the busses in the system under normal and abnormal system conditions. The PV curve is a representation of voltage change as a result of increased power transfer between two systems. The reported incremental transfers will be to the collapse point. As per the AESO requirements, no assessment based upon other criteria such as minimum voltage will be made at the PV minimum transfer. Voltage stability analysis for the post-project scenarios will be performed. For load connection projects, the load level modelled in post- Project scenarios are 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) analysis will be performed according to the Western Electricity Coordinating Council (WECC) Voltage Stability Assessment Methodology. The voltage stability criteria states, for load areas, post-transient voltage stability is required for the area modeled at a minimum of 105% of the reference load level for system normal conditions (Category A) and for single contingencies (Category B). For this standard, the reference load level is the maximum established planned load. Typically, voltage stability analysis is carried out assuming the worst case scenarios in terms of loading. The voltage stability analysis was performed by increasing load in AESO s Wetaskiwin Planning area (Area 31) and the following substations in AESO s Edmonton Planning area (Area 60): Bretona 45S, Cooking Lake 522S, Devon 14S, Blackmud 155S, Nisku 149S and Leduc 325S, and increasing the corresponding generation in the following AESO Planning Areas: The Calgary planning area (Area 6) The Fort MacLeod planning area (Area 53) The Lethbridge planning area (Area 54) The Glenwood planning area (Area 55) As per the voltage stability criteria, post transient techniques (all tap changers, all discrete capacitors locked, but static var compensators will be allowed to adjust) will used in applying the criteria and this information is reflected in all tables and graphs. Also for this analysis, no limits will be selected for the generation sources, non-negative active power constant MVA loads will be enforced and the existing power factor for the reference will be maintained. 3.3.1. Contingencies Studied Voltage stability analysis was performed for the Category A condition and all Category B contingencies in Edmonton (Area 60) and Wetaskiwin (Area 31) planning areas, including ties to surrounding areas for all pre- and post-project scenarios. RP-05-1674 Page 22 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 4. Pre-Project System Assessment 4.1. Pre-Project Load Flow Analysis Category A: 4.1.1. 2017 Summer Peak 2017 SP, Scenario 1 No Reliability Criteria violations were observed under Category A conditions for the 2017 WP scenario. Category B: No transmission voltage criteria violations were found under Category B in this scenario. Transmission line flows above the summer continuous ratings were identified for the Category B contingencies shown in Table 4.1-1 and illustrated in the plots in Attachment A. The identified line flows, including the flow marginally above short-term rating on transmission line under contingency of 604L (Nisku 149S to Blackmud 155S), are currently managed by real time operational practices. The voltage deviations observed at the St. Albert 99S substation, shown in Table 4.1-2, are known conditions currently managed by real time operational practices. The approved SWEATD, which includes reconfiguring the 138 kv system east of the City of Edmonton, is planned to alleviate the identified transmission line flows above the summer continuous ratings and the voltage deviations by Q4 2017. Table 4.1-1: Summary of System Performance 9 (Element Loading) [2017SP Pre-Project N-G-1 Line Loading Above Continuous rating] Contingency Limiting Branch Continuous Line Rating (MVA) Shortterm 10 Rating (MVA) Load Flow 11 (MVA) Pre-Project Normal Operation None - - - - % MVA Loading 86ST1 (Bigstone 86S 240/138 kv transformer) (North Calder 37S to Inland Cement Tap) 780L (East Edmonton 38S to Nisku 149S) 119 131 130.4 109.6 98 108 10 102.1 9 All line flows of load flow analysis are reported as percentage loading relative to normal line rating as shown in Table 2.6-1.. 10 10 minute summer emergency rating (MVA). 11 Load flow (MVA) is current expressed as MVA (ie. S = 3 x Vbase x Iactual). RP-05-1674 Page 23 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Contingency 780L (East Edmonton 38S to Nisku 149S) 604L (Nisku 149S to Blackmud 155S) 739L Acheson 305S to Stony Plain 434S 1045L (Jasper 805S to Sundance 310P) Limiting Branch (North Calder 37S to Inland Cement Tap) (North Calder 37S to Inland Cement Tap) (North Calder 37S to Inland Cement Tap) 905L (North Calder 37S to Wabamun 19S) Continuous Line Rating (MVA) Shortterm 10 Rating (MVA) Load Flow 11 (MVA) Pre-Project % MVA Loading 119 131 125.7 105.6 119 131 132.8 111.6 119 131 128.3 107.8 299 359 316.5 105.9 Table 4.1-2: Summary of System Performance (Voltage Deviation) [2017SP Pre-Project N-G-1] Contingency Substation Name and Number Bus No. Nominal kv Initial Voltage (kv) Voltage Deviations for POD Busses Only Post Transient (kv) % Change Post Auto (kv) % Change Steady State (kv) % Change for POD busses (North Calder 37S to St. Albert 99S) St. Albert 99S St. Albert 99S 2357 25 25.8 22.8 11.5 -- -- -- -- 4357 25 25.8 22.9 11.2 -- -- -- -- Category A: 4.1.2. 2017 Winter Peak 2017 WP, Scenario 2 No Reliability Criteria violations were observed under Category A conditions in this scenario. Category B: Under Category B conditions, no thermal or transmission voltage criteria violations were found in this scenario. Voltage deviations observed at the St. Albert 99S substation, shown in Table 4.1-3, are known conditions currently managed by real time operational practices. The approved SWEATD, which includes reconfiguring the 138 kv system east of the City of Edmonton, is planned to alleviate these voltage deviations by Q4 2017. Power flow analysis is illustrated in the plots in Attachment A. RP-05-1674 Page 24 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Table 4.1-3: Summary of System Performance (Voltage Deviation) [2017WP Pre-Project N-G-1] Contingency Substation Name and Number Bus No. Nominal kv Initial Voltage (kv) Voltage Deviations for POD Busses Only Post Transient (kv) % Change Post Auto (kv) % Change Steady State (kv) % Change for POD busses (North Calder 37S to St. Albert 99S) St. Albert 99S St. Albert 99S 2357 25 25.8 22.8 11.5 -- -- -- -- 4357 25 25.8 22.9 11.2 -- -- -- -- RP-05-1674 Page 25 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 5. Connection Alternatives. Overview In its DFO Report, FortisAlberta examined and ruled out the use of distribution-based solutions to address the project requirements. 12 This Report examined two transmission alternatives to serve the Project, as detailed in Section 5.2. 5.2. Connection Alternatives Identified Two alternatives were examined in this Report. A description of the developments associated with each alternative is provided below. Alternative 1 Upgrades at the Cooking Lake 522S Substation A new 25/33/42 MVA 138/25 kv transformer, one 25 kv feeder breaker and associated equipment would be installed at the Cooking Lake 522S substation. Alternative 2 Upgrades at the Blackmud 155S Substation A new 25 kv feeder breaker would be installed at the Blackmud 155S substation, coupled with the associated distribution upgrades. 5.3. Connection Alternatives Selected for Further Studies Alternative 1 was selected for further study. In its DFO Report, FortisAlberta concluded that Alternative 1 would address the distribution reliability and capacity concerns for the distribution system connected to the Cooking Lake 522S substation. 5.4. Connection Alternatives Not Selected for Further Studies FortisAlberta reported that while Alternative 2 would also address the capacity concerns for the distribution system connected to the Cooking Lake 522S substation, it would not address the area distribution reliability issues due to insufficient transformation capacity at adjacent substations. Therefore, Alternative 2 is not a technically acceptable solution and was not selected for further studies. 12 The DFO s analysis is included in section 4.1.1 of the DFO Report. RP-05-1674 Page 26 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 6. Technical Analysis of the Connection Alternatives 6.1. Load Flow 6.1.1. Alternative 1 The following is a summary of the Alternative 1 load flow analysis. Category A: 6.1.1.1. 2017 Summer Peak 2017SP, Scenario 3 No Reliability Criteria violations were observed under Category A conditions in the 2017 SP scenario. Category B: The same pre-project Category B thermal loadings above summer continuous ratings were observed under the post-project 2017 SP scenario as shown in Table 6.1-1 and illustrated in the plots in Attachment B. The pre-project voltage deviations at the St. Albert 99S substation were also observed post-project in the 2017 SP scenario as shown in Table 6.1-2. The Project had no material impact on the system performance. The identified thermal loadings above summer continuous ratings and voltage deviations are being managed by real time operational practices until mitigated by the SWEATD planned for Q4 2017. Table 6.1-1: Summary of System Performance 13 (Element Loading) [Scenario 3-2017 SP Post-Project N-G-1 Line Loading Above Continuous Rating] Contingency Limiting Branch Continuous Line Rating (MVA) Shortterm Rating (MVA) Load Flow 14 (MVA) Pre- Project % Loading 15 Load Flow (MVA) Post- Project % Loading % Loading Difference Post-Pre 86ST1 (Bigstone 86S 240/138 kv transformer) (North Calder 37S to Inland Cement Tap) 780L (East Edmonton 38S to Nisku 149S) 119 131 130.4 109.6 130.4 109.6 0.0 98 108 10 102.1 100.2 102.2 13 All line flows of load flow analysis are reported as percentage loading relative to normal line rating as shown in in Table 2.6-1 14 Load flow (MVA) is current expressed as MVA (ie. S = 3 x Vbase x Iactual). 15 % loading is current expressed as MVA (ie. S = 3 x Vbase x Iactual). RP-05-1674 Page 27 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Contingency Limiting Branch Continuous Line Rating (MVA) Shortterm Rating (MVA) Load Flow 14 (MVA) Pre- Project % Loading 15 Load Flow (MVA) Post- Project % Loading % Loading Difference Post-Pre 780L (East Edmonton 38S to Nisku 149S) 604L (Nisku 149S to Blackmud 155S) 739L Acheson 305S to Stony Plain 434S 1045L (Jasper 805S to Sundance 310P) (North Calder 37S to Inland Cement Tap) (North Calder 37S to Inland Cement Tap) (North Calder 37S to Inland Cement Tap) 905L (North Calder 37S to Wabamun 19S) 119 131 125.7 105.6 125.5 105.5-119 131 132.8 111.6 132.6 111.4-0.2 119 131 128.3 107.8 128.2 107.7-299 359 316.5 105.9 316.2 105.8 - Table 6.1-2: Summary of System Performance for Scenario 3 (Voltage Deviation) Contingency Substation Name and Number Bus No. Nominal kv Initial Voltage (kv) Post Transient (kv) Voltage Deviations for POD Busses Only % Change Post Auto (kv) % Change Post Manual (kv) % Change (North Calder 37S to St. Albert 99S) St. Albert 99S St. Albert 99S 2357 25 25.9 22.9 11.4 -- -- -- -- 4357 25 25.9 23.0 11.1 -- -- -- -- Category A: 6.1.1.2. 2017 Winter Peak 2017WP, Scenario 4 No Reliability Criteria violations were observed under Category A conditions in the 2017 WP scenario. Category B: No Reliability Criteria violations were observed under Category A conditions in the 2017 WP scenario. The results for the load flow are illustrated in the plots in Attachment B. The pre-project voltage deviations at the St. Albert 99S substation were also observed post- Project in the 2017 WP scenario as shown in Table 6.1-3. The Project had no material impact on the system performance. The identified voltage deviations are being managed by real time operational practices until mitigated by the SWEATD planned for Q4 2017. RP-05-1674 Page 28 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 Table 6.1-3: Summary of System Performance for Scenario 4 (Voltage Deviation) Contingency Substation Name and Number Bus No. Nominal kv Initial Voltage (kv) Post Transient (kv) Voltage Deviations for POD Busses Only % Change Post Auto (kv) % Change Post Manual (kv) % Change (North Calder 37S to St. Albert 99S) St. Albert 99S St. Albert 99S 2357 25 25.9 23.0 11.2 -- -- -- -- 4357 25 25.9 23.1 10.9 -- -- -- -- 6.2. Voltage Stability 6.2.1. Alternative 1 6.2.1.1. 2017 Winter Peak 2017WP, Scenario 4 Voltage stability analysis was performed for the 2017 WP scenario. The reference load level for the Wetaskiwin Planning Area (Area 31) and the load in the following substations in the Edmonton Planning Area (Area: Bretona 45S, Cooking Lake 522S, Devon 14S, Blackmud 155S, Nisku 149S and Leduc 325S is 333.8 MW. The minimum incremental load transfer for the Category B contingencies is 5.0% of the reference load or 16.7 MW to meet the voltage stability criteria (0.05 x 333.8 MW = 16.7 MW). Table 6.2-1 summarizes the voltage stability results for Category A and the worst five contingencies for voltage stability transfer margins. The voltage stability diagrams are shown in Attachment C. Table 6.2-1: Scenario 4: 2017 WP Voltage stability analysis results (Minimum transfer = 16.7 MW) Contingency From To Maximum incremental transfer (MW) Meets 105% transfer criteria? N-G System Normal 320 Yes 604L Nisku 149S Blackmud 155S 140 Yes 897L East Edmonton 38S Bretona 45S 140 Yes 86ST1 Bigstone 86S 240/138 kv transformer 160 Yes 780L East Edmonton 38S Nisku 149S 180 Yes 730L Bardo 197S East Camrose 285S 220 Yes RP-05-1674 Page 29 2016-05-03

Connection Engineering Study Report for AUC Application: AESO Project # 1674 7. Mitigation Measures The load flow analysis identified that, 780L, and 905L transmission line flows could be above summer continuous ratings under the studied Category B contingencies in the 2017 SP pre- and post-project scenarios. The identified thermal loadings are currently, and will continue to be, managed by real time operational practices until alleviated by the SWEATD project, planned for Q4 2017. RP-05-1674 Page 30 2016-05-03