CONNECTION ASSESSMENT
& APPROVAL PROCESS
ASSESSMENT SUMMARY
Applicant: Hydro One Networks Inc.
Project: Goderich TS- Station Upgrade
CAA ID: 2011-EX549
Final Report
Goderich TS-Station Upgrade
2011-EX549
IESO EXPEDITED SYSTEM IMPACT ASSESSMENT – 2011-EX549
1. Project Description
Hydro One Networks Inc. has proposed an addition of one 115/ 27.6 kV, 50/67/83 MVA
transformer and a single 27.6 kV bus at its existing Goderich TS in the western Ontario. The
station is connected to the IESO controlled grid through 115 kV radial circuit M18.
Presently, Goderich TS is comprised of one (T1)115/27 kV, 15/20/25 MVA transformer and
two (T2 and T3) 115/27 kV, 11/15 MVA transformers. According to the information provided
by Hydro One, the station has average peak load of approximately 40 MW.
Two 27.6 kV feeders from Goderich TS connect the 40 MW Capital Power Kingsbridge wind
farm to this station. These feeders will be relocated to the new 27.6 kV bus.
Thermal limitations restrict the connection of additional 2.9 MW of planned generation
projects to this station. The proposed transformer will mitigate this thermal limitation and
facilitate the connection of new generation projects.
The proposed in service date for the addition of the new transformer is July 7, 2012.
Figure 1: Goderich TS-Existing arrangement
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Goderich TS-Station Upgrade
2011-EX549
Figure 2: Goderich TS- Proposed arrangement
2. Technical specifications of the equipment
Transformer
Rating
Rated voltage
Under load tap changer
Grounding reactor
50/67/83 MVA
115/ 27.6 kV
+/- 22kV in +/- 16 steps
HV: Wye
LV: Zig-Zag- grounded
1.5 Ohm
High voltage equipment
Nominal voltage
Rated voltage
Ampacity (Continuous)
Short circuit capacity
115 kV
127 kV
600 A
50 kA
Transformer connections
Low voltage breakers
Equipment
Transformer breaker
Bus Tie breaker
Feeder breakers
Nominal
voltage
(kV)
27.6
27.6
27.6
Continuous
rating
(A)
3000
2000
2000
3
Interrupting
capability
(kA)
17
17
17
Cycles
5
5
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Goderich TS-Station Upgrade
2011-EX549
3. Findings
The review of the information provided for the proposed addition of new 115/ 27.6 kV,
50/67/83 MVA transformer at the existing Goderich TS concludes that the new transformer at
Goderich TS will not have any negative impact on the reliability of the IESO controlled grid.
4. IESO’s Requirements for Connection
The proposed connection must comply with all the applicable requirements from the
Transmission System Code (TSC), IESO Market Rules, and standards and criteria. The most
relevant requirements are summarized below:
Operating voltages requirement
All 115 kV equipment must be capable of continuously operating for all voltages within 113
kV and 127 kV, as per Appendix 4.1, Reference 2 of the Market Rules. Protective relaying
must be set to ensure that transmission equipment remains in-service for voltages between
94% of the minimum continuous and 105% of the maximum continuous values in the Market
Rules, Appendix 4.1.
All equipment shall be capable of continuously operating within the frequency range of 59.5
Hz and 60.5 Hz.
Fault levels
Hydro One shall ensure that the new equipment be designed to withstand the fault levels in the
area.
Appendix 2, of TSC, establishes the maximum symmetrical 3-phase and single line to ground
(SLG) fault level of 50 kA for 115 kV nominal voltage level and the 3-phase symmetrical fault
level of 17 kA and SLG symmetrical fault level of 21 kA for 27.6 kV nominal voltage level.
If any future system enhancement results in an increased fault level higher than the
equipment’s capability, Hydro One is required to replace the equipment at its own expense
with higher rated equipment capable of withstanding the increased fault level, up to the
maximum fault level specified in Appendix 2 of the Transmission System Code.
Protection requirement
New protection systems at Goderich TS must be designed to satisfy all the requirements of the
Transmission System Code. New protection systems must be coordinated with existing
protection systems.
Monitoring requirements
As specified in Appendix 4.16 of the Market Rules, Hydro One is required to install all the
equipment needed to provide telemetry data to the IESO on a continuous basis.
Facility Registration/Market Entry requirements
The connection applicant must complete the IESO Facility Registration/Market Entry process
in a timely manner before the IESO grants the final approval for the connection. Models and
data, including any controls that would be operational, must be provided to the IESO. This
information should be submitted at least seven months before energization to the IESOcontrolled grid, to allow the IESO to incorporate this project into IESO work systems and to
perform any additional reliability studies.
As part of the IESO Facility Registration/Market Entry process, the connection applicant must
provide evidence to the IESO confirming that the equipment installed meets the Market Rules
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Goderich TS-Station Upgrade
2011-EX549
requirements and matches or exceeds the performance predicted in this assessment. This
evidence shall be either type tests done in a controlled environment or commissioning tests
done on-site. In either case, the testing must be done not only in accordance with widely
recognized standards, but also to the satisfaction of the IESO. Until this evidence is provided
and found acceptable to the IESO, the Facility Registration/Market Entry process will not be
considered complete and the connection applicant must accept any restrictions the IESO may
impose upon this project’s participation in the IESO-administered markets or connection to the
IESO-controlled grid.
The evidence must be supplied to the IESO within 30 days after completion of commissioning
tests. Failure to provide evidence may result in disconnection from the IESO-controlled grid.
If the submitted models and data differ materially from the ones used in this assessment, then
further analysis of the project will need to be done by the IESO.
Notification of Conditional Approval
From the information provided, the review concludes that the proposed new transformer at
Goderich TS will not result in a material adverse effect on the reliability of the IESOcontrolled grid.
It is recommended that a Notification of Conditional Approval for Connection be issued for
the addition of new 115/ 27.6 kV, 50/67/83 MVA transformer , subject to the implementation
of the requirements listed in this report.
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