XXXX

Stl’ixwim Project

Interconnection System Impact Study

Report No. ASP2010-T046

August 2010

British Columbia Hydro and Power Authority

© British Columbia Hydro and Power Authority 2010. All rights reserved. .

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved ii

DISCLAIMER OF WARRANTY, LIMITATION OF LIABILITY

This report was prepared by the British Columbia Hydro And Power Authority (“BCH”) or, as the case may be, on behalf of BCH by persons or entities including, without limitation, persons or entities who are or were employees, agents, consultants, contractors, subcontractors, professional advisers or representatives of, or to, BCH (individually and collectively, “BCH Personnel”).

This report is to be read in the context of the methodology, procedures and techniques used, BCH’s or BCH’s Personnel’s assumptions, and the circumstances and constraints under which BCH’s mandate to prepare this report was performed. This report is written solely for the purpose expressly stated in this report, and for the sole and exclusive benefit of the person or entity who directly engaged BCH to prepare this report. Accordingly, this report is suitable only for such purpose, and is subject to any changes arising after the date of this report. This report is meant to be read as a whole, and accordingly no section or part of it should be read or relied upon out of context.

Unless otherwise expressly agreed by BCH:

1. any assumption, data or information (whether embodied in tangible or electronic form) supplied by, or gathered from, any source (including, without limitation, any consultant, contractor or subcontractor, testing laboratory and equipment suppliers, etc.) upon which BCH’s opinion or conclusion as set out in this report is based (individually and collectively, “Information”) has not been verified by BCH or BCH’s Personnel; BCH makes no representation as to its accuracy or completeness and disclaims all liability with respect to the Information;

2. except as expressly set out in this report, all terms, conditions, warranties, representations and statements (whether express, implied, written, oral, collateral, statutory or otherwise) are excluded to the maximum extent permitted by law and, to the extent they cannot be excluded, BCH disclaims all liability in relation to them to the maximum extent permitted by law;

3. BCH does not represent or warrant the accuracy, completeness, merchantability, fitness for purpose or usefulness of this report, or any information contained in this report, for use or consideration by any person or entity. In addition BCH does not accept any liability arising out of reliance by a person or entity on this report, or any information contained in this report, or for any errors or omissions in this report. Any use, reliance or publication by any person or entity of this report or any part of it is at their own risk; and

4. In no event will BCH or BCH’s Personnel be liable to any recipient of this report for any damage, loss, cost, expense, injury or other liability that arises out of or in connection with this report including, without limitation, any indirect, special, incidental, punitive or consequential loss, liability or damage of any kind.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

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COPYRIGHT NOTICE

Copyright and all other intellectual property rights in, and to, this report are the property of, and are expressly reserved to, BCH. Without the prior written approval of BCH, no part of this report may be reproduced, used or distributed in any manner or form whatsoever.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

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Executive Summary

The XXXX, the Interconnection Customer (IC), proposes to develop the Stl’ixwim project to deliver electric energy to BC Hydro (BCH) through the 2008 Clean Power Call (CPC). This report identifies the required system modifications for interconnecting the proposed Stl’ixwim Project. The Stl’ixwim Project includes six generating stations, each with a single generator: Chickwat 19 MW, Complimentary Creek 5 MW, Supplemental Creek 7 MW, Tyson Creek 9.3 MW, Upper Ramona Creek 7 MW and Lower Ramona Creek 7 MW. The IC will build a customer owned 26 km, 138 kV transmission line from their generation site and tap into BC Hydro circuit 1L37 at the Point of Interconnection (POI), approximately 5.5 km northwest from Malaspina Substation (MSA). The maximum power injection into the BCH system is 55 MW. The proposed Commercial Operation Date (COD) is November 1, 2012. In order to interconnect the Stl’ixwim project and its facilities into the BCH Transmission System at the POI, this System Impact Study (SIS) has identified the following issues and requirements: A “T” connection on circuit 1L37 with three 138 kV line disconnects will be created at the

POI. Direct Transfer Trip (DTT) scheme is required to disconnect Stl’ixwim generation for MSA

T1 or T5 outages. Various line protection work is required. An ADSS fiber optic line is needed from Stl’ixwim to MSA substation via the POI. The IC may need to install a circuit breaker with three independent poles and point-on-wave

(POW) controller at the plant site to reduce the magnetizing inrush current during step-up transformer energization from the system side. The IC will be responsible for undertaking the studies required to determine the necessity of an inrush/voltage-dip mitigation scheme if it elects to energize its facilities from the BCH system.

The step-up transformer in IC collection station is highly recommended to be a transformer with a high voltage Y-G to low voltage delta or a Y-Y auto-transformer with delta tertiary winding.

Out of step protection is required and should be provided by the IC. Islanded operation of the project is not allowed. Power quality protection is required to

prevent/mitigate possible islanded operation. The non-binding good faith cost estimate for Interconnection Network Upgrades required to

interconnect the proposed project to the BCH Transmission System is $2.8M. The estimated time to construct the Interconnection Network Upgrades required to

interconnect the project to the BCH Transmission System is estimated at 18 months. The Interconnection Facilities Study report will provide greater details of the Interconnection Network Upgrade requirements and associated cost estimates and estimated construction timeline for this project.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

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Table of Contents

DISCLAIMER OF WARRANTY, LIMITATION OF LIABILITY.............................................. ii COPYRIGHT NOTICE ................................................................................................................. iii Executive Summary ........................................................................................................................iv 1.0 Introduction ..........................................................................................................................1 2.0 Purpose of Study ..................................................................................................................2 3.0 Terms of Reference ..............................................................................................................2 4.0 Assumptions .........................................................................................................................2 5.0 System Studies .....................................................................................................................3

5.1 Steady State Pre-outage Power Flows..............................................................................3 5.2 Power Flow Based First Contingency Study....................................................................3 5.3 Transient Stability Study..................................................................................................6 5.4 Islanding ...........................................................................................................................8 5.5 Fault Analysis...................................................................................................................8 5.6 Analytical Studies ............................................................................................................8 5.7 Protection and Control & Telecommunications & Circuit Breakers ...............................9 5.8 BCH System Black Start Capability ................................................................................9 5.9 Transmission Line Upgrade Requirements ......................................................................9 5.10 Additional BCH Station Upgrades/Additions ................................................................10 5.11 Other Issues ....................................................................................................................10 5.12 Cost Estimate and Schedule ...........................................................................................10

6.0 Conclusion & Discussion ...................................................................................................11 Appendix A Project Single Line Diagram .................................................................................12 Appendix B Stl’ixwim Model and Data.....................................................................................13 Appendix C Typical post disturbance stability swings of the BCH - Stl’ixwim interconnected systems ...........................................................................................................................................18

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1.0 Introduction The project reviewed in this system impact study report is as described in Table 1 below.

Table 1: Summary Project Information

Project Name Stlixwim Interconnection Customer XXXX Point of Interconnection 1L37, 5.5 km from MSA Substation IC Proposed COD November 1, 2012 Type of Interconnection Service NRIS ERIS Maximum Power Injection (MW) 55 (Summer) 55 (Winter)Number of Generator Units 6 Plant Fuel Hydro

The XXXX, the Interconnection Customer (IC), proposes to develop the Stl’ixwim project to deliver electric energy to BC Hydro (BCH) through the 2008 Clean Power Call (CPC). The six generating stations of the Stl’ixwim project include: Chickwat 19 MW, Complimentary Creek 5 MW, Supplemental Creek 7 MW, Tyson Creek 9.3 MW, Upper Ramona Creek 7MW and Lower Ramona Creek 7MW. The IC will build a customer owned 26 km, 138 kV transmission line from their generating site and tap into BC Hydro circuit 1L37 at the POI, approximately 5.5 km northwest from Malaspina Substation (MSA). The maximum power injection into the BCH system is 55 MW. The proposed Commercial Operation Date (COD) is November 1, 2012. Figure 1 shows the connection of the Stl’ixwim project to the BCH Transmission System.

MSA 500kV

T1

T2

T5

MSA 230kV

MSA 132kV

PHR 132kV SEC 132kV

G

GSCG 132kV

SCG 13G

GIB 132kV

WFR 132kV

CKY 132kV

G

SKO 132kV

SKO 13G

T4

G

BOX 132kV

BOX 13G

T5

T6

T7

CKY 230kV CKY 60kV

G

CTN 60kV

CTN 13G

60L70

60L68

G

G

UMH 60kV UMH 13G

G

G

MAM 60kV MAM 13G

SQH 60kV

60L78

60L72

1L35 1L35

1L32

1L31

G

STX 132kV

1L37

T2

T3

SAY 132kV SAY 230kV

2L48

G

2L29

1L44

1L44

G

COM 132

COM 13G1

G

G

1L45

BRK132

Stlixwim IPPs: 1x19 MW 1x9.3 MW 3x7 MW 1x5 MWTotal: 55 MW

MTC 230kV

Figure 1 – The Stl’ixwim Project Interconnection Diagram The project interconnection single-line diagram can be found in Appendix A.

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2.0 Purpose of Study

The purpose of this SIS is to assess the impact of the interconnection of the proposed project on the BCH Transmission System. This study will identify constraints and Network Upgrades required for the reliable operation of the Transmission System.

3.0 Terms of Reference

This study investigates and addresses the voltage and overloading issues of the transmission networks in the vicinity of the Stlixwim generating stations as a result of the proposed interconnection. Topics studied include equipment thermal loading and rating requirements, system transient stability and voltage stability, transient over-voltages, protection coordination, operation flexibility, telecom requirements and high level remedial action scheme requirements. BCH planning methodology and criteria are used in the studies. The SIS does not investigate operating restrictions and other factors for possible second contingency outages. Subsequent internal network studies will determine the requirements for reinforcements or operating restrictions/instructions for those kinds of events. Impact to the bulk Transmission System is not included in the SIS and will be covered in a separate study. The work necessary to implement the network improvements identified in this SIS report will be described in greater detail in the Interconnection Facilities Study report for this project. 4.0 Assumptions The power flow conditions studied are base cases that include generation, transmission facilities, and load forecasts representing the queue position applicable to this project. Applicable seasonal conditions and the appropriate study years for the study horizon are also incorporated. The 2013 heavy winter, 2014 heavy summer and 2014 light summer load flow base cases were selected for this study. The study is based on the model and data information provided by the IC in the Generator Interconnection Data Form for this project. Reasonable assumptions are made to complete the study and the report, whenever such information is unavailable. The existing 1L35 conductor operating temperature is 49 °C. This is a rating typically assigned to older circuits in the BC Hydro system for which the original design data is not available. Recently, a specific review of the design information for this circuit indicated that it has sufficient ground clearance to operate at 90 °C; and the thermal ratings of 1L35 could be 493 Amp (112 MVA) for summer (30 deg C) and 594 Amp (135 MVA) for winter (10 deg C). These ratings are used in this SIS. As required in Bear Creek Hydro interconnection study, two circuit breakers 1CB3 and 1CB4 at Sechelt Substation (SEC) would be replaced in order to reduce the near-terminal fault clearing time to less than 6 cycles for the faults on 1L35 close to Sechelt. This is to prevent the generators at Clowhom generating plant from becoming unstable.

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A generation run-back scheme proposed to reduce area generation upon detecting an overload on 1L31/1L32 was included. This is to prevent transmission line overload after loss of 1L35. 5.0 System Studies

Power flow, short circuit and transient stability studies were carried out to evaluate the impact of the proposed interconnection. Studies were also performed to determine the protection, control and communication requirements and to evaluate possible over-voltage issues. 5.1 Steady State Pre-outage Power Flows

Pre-outage power flows are prepared to assess the impact of the project connection using three basic system load conditions: 2012 winter peak load, 2013 summer light load and 2013 summer peak load, and defined generation conditions. The steady-state power flow studies have indicated:

No voltage violations observed.

No circuits overloaded before and after the interconnection.

Table 2 provides the power flow study results for the proposed interconnection

Table 2: Steady-state Pre-outage Power Flow Study Results

Bus Voltage (in pu) Circuit Flow (MW)

System Condition

Stl’ixwim

Injection (MW)

STX132 MSA132 SEC132 GIB132 1L37 STX-MSA

1L35 SEC-MSA

1L32 SEC-BIB

1L31 GIB-CKY

2012 HW 55 1.050 1.049 1.036 1.034 52 27 10 8

2013 LS 55 1.050 1.049 1.055 1.053 52 75 2 20

2013 HS 55 1.055 1.054 1.055 1.053 52 61 6 22

Note: LS: light summer load;

HW: heavy winter load; HS: heavy summer load

5.2 Power Flow Based First Contingency Study

Power flow based single contingency (N-1) studies have been conducted to check if the post-disturbance performance including bus voltage deviation and facility loading meets the planning criteria under different system load conditions including heavy winter, heavy summer and light summer.

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The studies of the single contingency outage situations have indicated that there are transmission equipment overload problems and voltage violation due to the addition of the Stl’ixwim project. The violation and the recommended solution are listed in Table 3.

Table 3: Reinforcement Requirement Based on Power Flow Study System Violation System Contingency New Requirement

1L31 thermal overload 1L32 thermal overload

Loss of MSA T1/MSA T5

Direct transfer trip of 1L37 following MSA T1 or MSA T5 contingency.

Note: MSA T1 and MSA T5 are within the same protection zone.

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The contingency study results based on 2013 summer light load are listed in Table 4.

Table 4: The Power Flow Study Results

after Single Element Contingency

Bus Voltage (in pu) Power Flow (MW)

Contingency STX132 MSA132 SEC132 GIB132

1L37 STX-MSA

1L35 SEC-MSA

1L32 SEC-BIB

1L31 GIB-CKY

2013 LS System Normal (Benchmark)

1.050 1.049 1.055 1.053 52 75 2 20

N/A 1.054 1.059 1.058 N/A 83 -7 12 Loss of 1L37 0.53% 0.38% 0.43% 74.3% -11.2% 20.6%

1.025 1.024 1.011 0.984 52 -46 123 132 Loss of MSA T5 1

-2.33% -2.36% -4.21% -6.56% 90.9% -41.1% 206.4% 222.4%

1.042 1.040 1.050 1.048 52 70 7 26 Loss of MSA T5 (Add a 230-138kV

transformer) 2 -0.76% -0.77% -0.50% -0.47% 90.9% 62.3% 11.5% 43.1%

N/A 1.030 1.032 1.020 N/A 4 72 88 Loss of MSA T5 (RAS) 3, 5

-1.80% -2.21% -3.20% 3.9% 121.6% 147.7%

1.073 1.072 1.031 1.018 52 N/A 77 92 Loss of 1L35 4, 5

2.20% 2.23% -2.27% -3.38% 90.9% 129.0% 154.5%

1.050 1.049 1.057 1.047 52 77 N/A 19 Loss of 1L32 0.05% 0.05% 0.17% -0.62% 90.9% 68.4% 31.8%

1.048 1.047 1.062 1.068 52 95 -19 N/A Loss of 1L31 -0.15% -0.15% 0.61% 1.39% 90.9% 85.1% -31.7%

1.040 1.039 1.059 1.069 52 122 -45 -27 Loss of CKY T4 6

-0.92% -0.93% 0.32% 1.52% 90.9% 108.9% -76.4% -46.0%

Note 1: Loss of MSA T5 causes 1L31/1L32 overload. Note 2: The option of adding a new MSA 203-132 kV 150 MVA transformer. This option is not

recommended. Note 3: The recommended option of direct transfer trip of 1L37 following MSA T5 contingency. Note 4: Loss of 1L35 causes 1L31/1L32 overload. Note 5: As per Clowhom transmission upgrade requirement, there would be a run-back scheme to reduce

Bear Creek generation upon detecting an overload on 1L31/1L32. This could prevent the transmission lines from overloading.

Note 6: Loss of CKY T4 causes 1L35 overload which is caused by other new IPPs interconnected between Cheekye and Sechelt. There will be RAS or run-back schemes associated with those new IPPs to prevent the transmission line overload.

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5.3 Transient Stability Study

A series of transient stability studies under various system operating conditions including the heavy winter case and the most severe light summer case have been performed. The model of the generating project was based on the IC’s data submission plus additional assumptions where the IC’s data was incomplete or inappropriate. The models and data values of the key components are shown in Appendix B. After the addition of Stl’ixwim generation, some system disturbances will cause other generators in the vicinity to become unstable. The violations and recommended solutions are summarized in Table 5.

Table 5: Reinforcement Requirement Based on Transient Stability Study System

Disturbance Violations New Requirement

Fault on MSA T1 / MSA T5

Clowhom (COM) generating units become unstable

Direct transfer trip of 1L37 within 9 cycles after MSA T1/MSA T5 fault initiation. MSA T1 and MSA T5 are within the same protection zone.

Fault on 1L37 close to Stl’ixwim POI

Clowhom (COM) generating units become unstable

Add telecom-assisted protection to 1L37 so that the Malaspina terminal (remote-end) fault clearing time is less than 9 cycles for 1L 37 faults close to Stlixwim.

Under severe disturbances on the 132 kV bus or transformer at Malaspina, it is anticipated that the generating units will become unstable and the swing center will be inside the IC plant (generator-transformer). The IC must be able to detect and be tripped off for out-of-step conditions. Out of step relaying at the IC plant will be the responsibility of the IC. BCH can provide apparent impedance versus time plots of stable and unstable swings if requested. The transient stability study results for 2013 summer light load are summarized in Table 6.

Table 6: Transient Stability Study Results (Pre-outage condition: 2013 LS)

Fault Clearing Time (Cycles)

Case Contingency 3PH Fault Location

IPP Injection

(MW) Near End

Far End

Stl’ixwim and Nearby

Generators Stability

Performance 1

1 1L37 Section (STX-MSA)

MSA132 55 8 23 Acceptable

2 1L37 Section (STX-MSA)

STX132 55 8 23 Loss of

synchronism

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2a 1L37 Section (STX-MSA) w/ telecom 2

STX132 55 8 9 Acceptable

3 MSA T5 MSA132 55 8 6 Loss of

synchronism

3a MSA T5 w/

T6 3 MSA132 55 8 6 Acceptable

3b MSA T5 w/

RAS 4 MSA132 55 8 6 Acceptable

4 MSA T5 MSA230 55 6 8 Loss of

synchronism

4a MSA T5 w/

T6 3 MSA230 55 6 8 Acceptable

4b MSA T5 w/

RAS 4 MSA230 55 6 8 Acceptable

5 MSA T1 MSA500 55 5 6 Loss of

synchronism

5a MSA T1 w/

T6 3 MSA500 55 5 6 Acceptable

5b MSA T1 w/

RAS 4 MSA500 55 5 6 Acceptable

6 1L35 MSA-

SEC MSA132 55 8 9 Acceptable

7 1L35 MSA-

SEC SEC132 55 8 9

Loss of synchronism

7a 1L35 MSA-SEC w/ CB 5 SEC132 55 6 9 Acceptable

8 1L32 SEC-

GIB SEC132 55 8 9 Acceptable

9 1L32 SEC-

GIB GIB132 55 8 9 Acceptable

Note: 1 : Unacceptable stability performance means unstable rotor angle results

or violation of voltage dip according to BCH planning criteria. Note 2 : Add telecom-assisted protection to 1L37 so that the Malaspina terminal

(remote-end) fault clearing time is less than 9 cycles for 1L 37 faults close to Stlixwim.

Note 3 : The option of adding a new MSA 203-132 kV 150 MVA transformer. This option is not recommended.

Note 4 : The recommended option of direct transfer trip of 1L37 in 9 cycles after MSA T1/MSA T5 fault initiation. MSA T1 and MSA T5 are within the same protection zone.

Note 5 : As per Bear Creek Hydro project requirement, the two circuit breakers 1CB3 and 1CB4 at SEC substation will be replaced so that the near-terminal fault clearing time is less than 6 cycles for faults on 1L35 close to Sechelt.

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5.4 Islanding

Islanded operation is normally not an acceptable practice in BCH. Power quality protection will be required at the generating units to detect abnormal system conditions such as under/over voltage and under/over frequency and subsequently trip the units. The settings of these protective relays must conform to existing BCH practice for generating plants so that the generator will not trip for normal ranges of voltages and frequencies.

5.5 Fault Analysis The short circuit analysis for the CPC System Impact Studies are based upon the latest BCH system short circuit model, which includes project equipment and impedances provided by the successful CPC Interconnection Customers. The model included higher queued projects and planned system reinforcements but excluded the Northwest Transmission Line (NTL) and other lower queued projects. At this stage, the report does not provide Thevenin impedances at the POI due to uncertainties associated with the system reinforcement options identified for the CPC projects and the statuses of higher queued projects. However, these Thevenin impedances, including the ultimate fault levels at POI, will be made available to Interconnection Customers upon request. BCH will work with the IC to provide accurate data as required during the project design phase.

5.6 Analytical Studies

EMTP simulations for abrupt line openings without a fault exhibit severe temporary over voltages under certain IC generation scenarios. The overvoltage is caused by a positive sequence series resonance involving the proposed project equivalent source inductance (generator Xd plus transformer plus 25kV line inductances) and the line charging capacitance for certain generation scenarios. It is recommended to delay the opening of the MSA end of 1L37 for all non-fault trips (i.e. trips originating from local or remote supervisory) and implement a Direct Transfer Trip (DTT) scheme to disconnect the Stl’ixwim project. The “back-of-the-envelope” calculation indicates that voltage sag at the POI is out of range when energizing the customer-owned step-up transformer (500 MVA, 138/25kV). A circuit breaker with three independent poles and point-on-wave (POW) controller could be required to reduce the magnetizing inrush current during transformer energization.

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5.7 Protection and Control & Telecommunications & Circuit Breakers

Protection, control and telecom requirements for the Stl’ixwim Project have been reviewed. The main items are summarized below: Telecommunication-aided protection scheme is required on 1L37 to reduce the

Malaspina terminal (remote-end) fault clearing time to less than 9 cycles for faults on 1L 37 close to Stlixwim.

IC is responsible to provide line protection at Stl’ixwim site, which should be SEL-311L-1. BCH is to specify relay model and telecommunications interfaces and also determine core line protection settings.

Revise existing PHR 25F53 protection to reflect removal of Tyson Creek IPP. Direct transfer trip (DTT) scheme is required to trip Stl’ixwim generation for MSA T1

or T5 outages. Delay non-fault tripping of MSA 1CB5 and 1CB6. Opening of the 2nd breaker at MSA

shall key into the MSA terminal of 1L37 line protection. This signal will be carried via the 1L37 relay to relay signalling and will result in advance tripping of the Stl’ixwim terminal of 1L37.

An ADSS fibre optic line is needed from Stl’ixwim substation to MSA via the POI. BC Hydro will supply, install and terminate the fiber optic portion between MSA and the POI. The IC will supply, install and terminate the fiber optic portion between Stilixwim substation and the POI.

Modifications of the control functions at SAY and MSA are required to integrate the telemetry and status information from the new project; and updates of the existing database and displays at FVO/SIO will be implemented to accommodate the new project.

5.8 BCH System Black Start Capability

BCH does not require the proposed project to have black start (self-start) capability. However, if the IC desires their facilities to be energized from the BCH system, the IC is required to apply for an Electricity Supply Agreement. Upon receipt of this application, a plant pick-up study would be required to assess the impact of energizing the IC’s facilities. A high level plant pick-up screening was performed as part of the SIS and any issues are identified in Section 5.6.

5.9 Transmission Line Upgrade Requirements

A “T” connection will be created on 1L37 at the POI. The interconnection is depicted in Appendix A and the project scope of transmission line upgrades includes: Installation of three standard no-load break 138kV disconnect switch structures

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Installation of one standard 138kV tap structure Possible acquisition of anchor easements and a short section of right-of-way from the

BCH circuit to the IC’s POI switch Minor vegetation clearing

5.10 Additional BCH Station Upgrades/Additions

No additional BCH station upgrades are required.

5.11 Other Issues Potential Operation Issue: The 1L37 line from MSA to SAY has to be reverted after 2L48 outage. Considering the service risk represented by the tap to Stl’ixwim and system protection issues, it is required to disconnect the IC and their tap line from the system at the POI as illustrated in Figure 2. Transformer Winding Configuration: The IC has a 25-132 kV step-up transformer at their collector station, which is a Yg-Yg transformer which is quite unusual in the BCH Transmission System. The zero sequence contribution from Stl’ixwim into 1L37 will therefore be dependent on the amount of generation online behind the transformer. This may cause problems with the backup protection being unable to detect ground faults under low generation conditions. It is recommended to use a transformer with HV YG to LV Delta or a Y-Y autotransformer with delta tertiary winding.

5.12 Cost Estimate and Schedule

The non-binding good faith cost estimate for the Interconnection Network Upgrades is $2.8M. The Interconnection Facilities Study report will provide more detailed information of the cost estimates. The estimated time to construct the Interconnection Network Upgrades is estimated at 18 months after the Standard Generation Interconnection Agreement is signed and BCH capital project is approved. A more detailed construction timeline will be provided in the Interconnection Facilities Study report. BCH system upgrades triggered by CPC projects are being determined and the IC may be required to post security to cover one or more upgrade. Further information will be provided over the next few months.

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6.0 Conclusion & Discussion In order to interconnect the Stl’ixwim Project to the BCH Transmission System at the POI, this SIS has identified the following issues and requirements: A “T” connection on line 1L37 with three 138 kV line disconnects will be created at the POI. Direct transfer trip (DTT) scheme is required to disconnect Stl’ixwim generation for MSA

T1 or T5 outages. No fault opening of 1L37 at MSA with 1CB5 and 1CB6 will be delayed so that Stl’ixwim

will be tripped before opening 1L37 to prevent over voltages. 1L37 line protections will be replaced by telecommunication-aided protection scheme at both

MSA and SAY. The IC is responsible to provide consistent line protections at Stl’ixwim to 1L37 and the “tap” line from Stl’ixwim to the POI.

An ADSS fiber optic line in needed from Stl’ixwim to MSA substation via the POI. BC Hydro will supply, install and terminate the fiber optic portion between MSA and the POI. The IC will supply, install and terminate the fiber optic portion between Stilixwim substation and the POI at their cost.

The IC may need to install a circuit breaker with three independent poles and point-on-wave (POW) controller at the plant site to reduce the magnetizing inrush current during step-up transformer energization from the system. The IC will be responsible for undertaking the studies required to determine the necessity of an inrush/voltage-dip mitigation scheme if it choose energizing its facilities from the system.

The step-up transformer in the IC collection station is highly recommended to be a transformer with HV YG to LV Delta or a Y-Y autotransformer with delta tertiary winding.

Out of step protection is required and should be provided by Stlixwim. Islanded operation is not allowed. Power quality protection is required to prevent/mitigate

possible islanded operation. With Stl’ixwim connected to 1L37 using a tap, the project could be disconnected from 1L37

when the circuit is connected between SAY and MSA to provide backup supply during 2L48 outages.

The associated system protection, controls and telecommunications work are required in the related transmission lines, substation and BCH control centers.

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Appendix A Project Single Line Diagram

1

5.0

0.3R

1.0000

1.0000

1 7.

0

0.5R

1.0000

1.0000

9113SAY 132

9828STX 25

1.0000

140PHR 132

0.9804

1.0000 1.0000

202MSA 230

1

19.0

2.3R

1.0000

1.0000

7.0

0.5R

1.0000

1.0000

1

7.0

0.3R

1.0000

1.0000

1.0250

1

102MSA 132

9926RML 25T2

9028CKW 4G4

9935SSZ 25T5

9035SSZ 4G5

9933CCC 25T6

T35/T36: Stlixwim

1L37, 5.5 km1L37, 17 km

1L35, 3 km

L1: 7.3 kmL2: 1.9 km cableL3: 16.9 km

L4: 7 km

L5: 1 km

L8: 0.4 km

840TYS 25T1

L6: 4 km

9.3

0.4R

1.0000

1.0000

1

L9: 5.4 km

40TYS 4G1

9033CCC 4G6

L7: 4.9 km

9026RML 4G2

9027RMU 4G3

9928CKW 25T4

9927RMU 25T3

9728STX 37P

9128STX 132

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 13 of 21

Appendix B Stl’ixwum Project Model and Data

Stl’ixwim Project Generator Model

The contents of this section have been removed due to the proprietary nature of the information.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 14 of 21

Stl’ixwim Project Generator Model

The contents of this section have been removed due to the proprietary nature of the information.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 15 of 21

Stl’ixwim Project Generator Model

The contents of this section have been removed due to the proprietary nature of the information.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 16 of 21

Stl’ixwim Project Generator Model

The contents of this section have been removed due to the proprietary nature of the information.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 17 of 21

Stl’ixwim Project Excitation Control System Model

The contents of this section have been removed due to the proprietary nature of the information.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 18 of 21

Appendix C Typical post disturbance stability swings of the BCH - Stl’ixwim interconnected systems

Channel Plot

1 - ANGL 9002[UTR 13G 13.800]1 : outxx_MSA T1&5_MSA132_3s_060716 - ANGL 41[COM 13G1 13.200]1 : outxx_MSA T1&5_MSA132_3s_06079 - ANGL 9026[RML 4G2 4.1600]1 : outxx_MSA T1&5_MSA132_3s_0607

Time (seconds)32.521.510.50

10,000

9,000

8,000

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

Rotor angle swings for MSA transformer T5 three phase fault at 132 kV terminal Without direct transfer trip of the 1L37 line.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 19 of 21

Channel Plot

1 - ANGL 9002[UTR 13G 13.800]1 : outxx_MSA T1&5_MSA132_3s_RAS_061016 - ANGL 41[COM 13G1 13.200]1 : outxx_MSA T1&5_MSA132_3s_RAS_0610

Time (seconds)32.521.510.50

110

100

90

80

70

60

50

40

30

20

10

0

Rotor angle swings for MSA transformer T5 three phase fault at 132 kV terminal With direct transfer trip of the 1L37 line in 9 cycles (RML generator has been tripped).

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 20 of 21

Channel Plot

459 - VOLT 202 [MSA 230 230.00] : outxx_MSA T1&5_MSA132_3s_0607462 - VOLT 102 [MSA 132 132.00] : outxx_MSA T1&5_MSA132_3s_0607469 - VOLT 106 [SEC 132 132.00] : outxx_MSA T1&5_MSA132_3s_0607

Time (seconds)32.521.510.50

1.25

1

0.75

0.5

0.25

0

Voltage swings for MSA transformer T5 three phase fault at 132 kV terminal Without direct transfer trip of the 1L37 line.

Stl’ixwim Project Interconnection System Impact Study ASP2010-T046

© British Columbia Hydro and Power Authority, 2010. All rights reserved. Page 21 of 21

Channel Plot

459 - VOLT 202 [MSA 230 230.00] : outxx_MSA T1&5_MSA132_3s_RAS_0610462 - VOLT 102 [MSA 132 132.00] : outxx_MSA T1&5_MSA132_3s_RAS_0610469 - VOLT 106 [SEC 132 132.00] : outxx_MSA T1&5_MSA132_3s_RAS_0610

Time (seconds)32.521.510.50

1.25

1

0.75

0.5

0.25

0

Rotor angle swings for MSA transformer T5 three phase fault at 132 kV terminal With direct transfer trip of the 1L37 line in 9 cycles.