N-1Work Order - Redacted
12 passages
DESCRIPTION: This project involves the construction of an 8.5 kilometer new three-phase feeder from the 92H Tidewater Substation to offload and double circuit the existing feeder 92H-331 along Peggy's Cove Road. The new feeder construction...
AI summary This project entails constructing an 8.5 km three-phase feeder from the 92H Tidewater Substation to relieve and double-circuit the existing 92H-331 feeder along Peggy's Cove Road. It aligns with a separate project (CI C0071888) to replace the 92H-T61 transformer with a 25 MVA unit, addressing winter peak-load overloads at the substation and feeder.
Why do this project? The 92H-331 feeder at Tidewater substation is overloaded during periods of high load. The construction of the new three phase feeder section along Peggys Cove Road from 92H substation will allow for the offload of 92H-...
AI summary The 92H-331 feeder at Tidewater substation is overloaded, necessitating the construction of a new three-phase feeder along Peggys Cove Road to offload 92H-331, improve reliability, and reduce strain on the distribution system. A planning study (M-AREA-2025-002) outlines immediate and long-term solutions, including a new substation, to address capacity and reliability challenges in the area.
3.1 Feeders Historical feeder loading was derived from peak load analyses based on AMI measurements from 2022 onward. Limited SCADA/PI data is available, and data prior to 2022 could not be validated. The load forecast is developed using a...
AI summary The historical feeder loading is based on AMI measurements from 2022 onward and uses linear regression to forecast future loads. The forecast includes a 90th-percentile deviation adjustment to account for variability and produce a conservative planning forecast.
3.2 Transformers Historical transformer loading was derived from peak load analyses based on AMI measurements from 2022 onward. There was limited historical data available, and data prior to 2021 (for 137H) and prior to 2022 (for 92H) coul...
AI summary The historical transformer loading analysis uses AMI data from 2022 onward, with limited data prior to 2021 and 2022. Load forecasts are based on linear regression trends and 90th-percentile deviation adjustments to account for variability, producing a conservative planning forecast.
6.1.1 92H-T61 Replacement Winter peak load supplied by transformer 92H-T61 significantly exceeds the transformer rating when hydro is unavailable. Replacement with a new 15/20/25 MVA transformer is required. Monitoring limitations, rapid l...
AI summary Transformer 92H-T61 is overloaded during winter when hydro is unavailable, requiring replacement with a larger unit. Temporary solutions like modified hydro dispatch and mobile transformers are insufficient. Alternatives such as load transfers or adding a second transformer are infeasible due to infrastructure constraints and high costs. Replacement remains the only viable long-term solution.
6.1.2 92H Fourth Feeder Feeder 92H‑331 is severely overloaded and growing rapidly. During extreme cold weather events, the feeder required active monitoring for potential load shedding to avoid exceeding conductor and protection limits. To...
AI summary Feeder 92H-331 is overloaded and requires a new fourth feeder (92H-335) to alleviate congestion. The proposed 6 km extension along Peggy's Cove Road would reduce 92H-331's load to 179 A, with further extension contingent on load growth. Alternatives like using 92H-332 were rejected due to existing overload.
6.2.3 Alternative C: Feeders from Lucasville A third alternative is leveraging capacity from the 131H-Lucasville substation. A new feeder can be built into Stillwater Lake to offload 137H-412 and enable feeder reconfigurations. This additi...
AI summary Alternative C proposes building new feeders from the Lucasville substation to increase contingency capacity. One feeder would provide 44 MVA, but a second feeder is required to reach 48 MVA, enabling deferral of the Stillwater Lake substation upgrade.
6.3 Tidewater Capacity The immediate concerns for Tidewater are addressed by the immediate actions recommended in Section 6.1. However, in 2029 the feeder 92H-332 is expected to exceed the 325 A planning criterion and the total station loa...
AI summary The Tidewater area faces capacity and voltage challenges by 2027-2033, including overloaded feeders (92H-332, 103H-432, 92H-334) and low voltage in Five Island Lake. Solutions include converting 12kV distribution in Hubley, expanding 92H Tidewater capacity, and infrastructure upgrades like line extensions. Deteriorated 92H substation structures also require attention.
7.5.1 Tidewater Alternative A: Hubley Conversion and Transfer to Stillwater Lake This alternative converts portions of the Hubley distribution system from 12 kV to 25 kV and transfers this load to the proposed Stillwater Lake substation. T...
AI summary Tidewater Alternative A involves upgrading Hubley's distribution system from 12 kV to 25 kV and transferring load to the Stillwater Lake substation. This reduces Tidewater substation loading, improves reliability via new feeder ties, resolves feeder overloads, and leverages existing infrastructure, making it the lowest-cost, preferred long-term solution.
2026: - Replace transformer 92H-T61 with a 15/20/25 MVA unit. REDACTED CI C0080102 Attachment 1 Page 43 of 52 - Build new feeder 92H-335 and extend a minimum of 6 km along Peggy's Cove Road.
AI summary The 2026 plan includes replacing transformer 92H-T61 with a 15/20/25 MVA unit and constructing a new 6 km feeder line (92H-335) along Peggy's Cove Road. These infrastructure upgrades aim to enhance grid capacity and reliability in the region.
2028: - Construct a third feeder from Stillwater Lake. - Convert Hubley distribution from 12 kV to 25 kV. - Transfer Hubley load to the Stillwater Lake substation by creating a feeder tie with 103H-Lakeside.
AI summary Proposed infrastructure upgrades include constructing a third feeder from Stillwater Lake, converting Hubley's distribution to 25 kV, and transferring load via a feeder tie to the Stillwater Lake substation, aiming to enhance grid reliability and capacity.
2037: - Install a second transformer at 137H-Hammonds Plains. Implementation of these projects will restore compliance with planning criteria, provide sufficient contingency capacity, and accommodate forecast load growth in the Tidewater a...
AI summary The document outlines the installation of a second transformer at 137H-Hammonds Plains to restore compliance with planning criteria, ensure contingency capacity, and accommodate load growth in Tidewater and Hammonds Plains. Continued monitoring of development in Bedford West, Sandy Lake, and Hubley/Timberlea is recommended to adjust project timelines and identify long-term needs.
101403NSEB (NSPI) IR-1 to IR-15
2 passages
Request IR-12: - a. Most 92H feeders are adjacent to 25 kV feeders supplied from the 137H and 103H substations. Please explain why under Alternative A, NS Power proposes to convert only a portion of 92H-332 to 25 kV instead of the entire c...
AI summary Request IR-12 seeks technical and cost explanations from NS Power regarding partial 25 kV conversions on the 92H substation, transformer specifications, and alternative grid modernization measures. Questions focus on feasibility, costs, and load management solutions for infrastructure upgrades.
Request IR-15: - a. Did NS Power explore the following alternatives for the project: - i. Conversion of feeders 92H-331 and 92H-332 to 25 kV system, and if technically possible, convert 92H-334 to 25 kV system. - ii. Installation of a new...
AI summary Request IR-15 asks NS Power to detail alternatives explored for a project, including voltage conversions, transformer installations, feeder interconnections, temporary overload solutions, and substation rebuilding. The inquiry focuses on technical feasibility, preferred options, and rationale for non-selection.