Topic:"Distribution" in M13084

DESCRIPTION: In order to accommodate the anticipated load growth and provision of a secondary supply from the Cape Breton Regional Hospital redevelopment, NS Power must undertake a rebuild and reconductoring of current infrastructure (at t...

AI summary NS Power is required to rebuild and reconductoring distribution lines in Sydney to accommodate load growth and provide a secondary supply to the Cape Breton Regional Hospital. The project involves installing new poles and conductor, with costs to be paid by the hospital.

JUSTIFICATION: Justification Criteria: Distribution System Sub Criteria: Pole Strength

AI summary The justification criteria for the distribution system include pole strength as a sub-criteria, indicating a focus on infrastructure integrity and reliability.

as projects with a primary purpose that is integral to the effective operation of a system. These collective capabilities provide a service that is made up of nodes and vectors into a grid or system." Using this definition, power transmiss...

AI summary The text discusses the definition and scope of power transmission projects, emphasizing their role as vectors in the grid system, the importance of right-of-way and regulatory considerations, and the similarities between transmission and distribution in terms of estimation principles.

2.1 Transmission The 111S-Prime Brook substation is fed via the 138 kV line L6539 and is located between the 2S-Victoria Junction substation and the 3S-Gannon Road substation. The 11S-Keltic Drive substation is fed from the 69 kV line L557...

AI summary The text describes the transmission infrastructure in the Sydney Area, including various substations and their feeding lines, and mentions a Load Impact Study. It provides details on the electrical connections between different substations.

2.2 Distribution The distribution system being investigated in this report includes 12.5 kV feeders supplied by the 111S-Prime Brook and 4S-Townsend Street substations as shown in Figure 3. The 111S-Prime Brook substation supplies four 12....

AI summary The document details the distribution system being investigated, focusing on 12.5 kV feeders supplied by the 111S-Prime Brook and 4S-Townsend Street substations, as well as other nearby substations and their respective circuits. It also mentions the conversion of the 6S-Terrace Street Substation from 4.2kV to 12.5kV and its potential reuse for the CBRH.

There is currently one transformer supplying the feeder circuits out of the 111S-Prime Brook substation. 111S-T61 is a 138 – 13.2 kV transformer unit rated for 15/20/25 MVA that supplies four 12.5 kV distribution circuits for customers in...

AI summary The text describes the current transformer setup at the 111S-Prime Brook substation, including the specifications of transformer 111S-T61 and its role in supplying power to the Sydney area, as well as the supply arrangement for the Cape Breton Regional hospital.

Figure 4 shows the 111S substation and Appendix A contains a copy of the complete system one-line diagram for 111S. Qualitative descriptions of the two relevant feeders are located in Table 4. Table 4: Relevant 111S-Prime Brook 12.5 kV Fee...

AI summary The text describes the 111S substation and provides qualitative descriptions of two relevant feeders in Table 4. It includes details about the feeders' routes, tie-points, and equipment. The section also references a substation named 4S-Townsend Street.

Figure 5 shows the 4S substation and Appendix A contains a copy of the complete system one-line diagram for 4S. A qualitative description of the relevant feeders is provided in Table 5. Table 5: Relevant 4S-Townsend Street 12.5 kV Feeders...

AI summary The text describes the 4S substation and its relevant feeders, providing details on their locations, tie points, and equipment. It also mentions a proposed load section, indicating upcoming discussions on load requirements.

- 1. The Load Customer is requesting an in-service date prior to Dec 31, 2022. - 2. The power factor of the project is no less than 0.90. The current supply to the CBRH is provided via feeder 111S-311 out of the 111S-Prime Brook Substation...

AI summary The Load Customer is requesting an in-service date prior to Dec 31, 2022, and the project's power factor is no less than 0.90. The current supply to CBRH is provided via feeder 111S-311 from the 111S-Prime Brook Substation along Reservoir Road.

4.2 Configuration and Grounding NS Power's primary Distribution System is a 3-phase, 4-wire multi-grounded common neutral system ("effectively grounded-wye") operated at three typical voltage levels: - 4,160 Volts line to line; 2,400 Volts...

AI summary This section describes NS Power's distribution system, including voltage levels and transformer configurations. The system operates at multiple voltage levels and uses various transformer configurations to ensure proper grounding and short-circuit protection.

4.3 Voltage Standards NS Power maintains voltage levels at all points on the Distribution Systems in compliance with "CSA CAN-3-C235-1983 (R2015) Preferred Voltage Levels for AC Systems, 0 to 50,000 Volts, Electric Power Transmission and D...

AI summary NS Power adheres to voltage standards set by CSA CAN-3-C235-1983 (R2015) to ensure compliance with preferred voltage levels for AC systems within the Distribution Systems.

4.4 Phasing Phasing is not standardized across NSPI's Distribution Systems. Where necessary, the phase sequence and the direction of rotation must be coordinated with NS Power's Distribution System.

AI summary The phasing of NSPI's Distribution Systems is not standardized, and coordination with NS Power's Distribution System is required for phase sequence and direction of rotation where necessary.

REDACTED CI C0085185 Attachment 1 Page 16 of 60 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Cape Breton Regional Hospital (CBRH) Load Impact Study power output of a generator. NS Power has established guidelines for the Distribution System...

AI summary The document discusses the impact of unbalanced loads on the Distribution System, noting that while the system is three-phase, many loads are connected phase to ground, leading to voltage unbalance. NS Power has established guidelines for voltage dips and flicker, with normal phase-to-phase voltage unbalance typically below 3%.

4.6 Voltage and Current Distortion NS Power has adopted "IEEE 519 – 2014 IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems". This establishes harmonic distortion limits for the Distribution System...

AI summary NS Power has adopted IEEE 519 – 2014 to establish harmonic distortion limits for the Distribution System, providing expected harmonic voltage distortion levels.

REDACTED CI C0085185 Attachment 1 Page 18 of 60 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Cape Breton Regional Hospital (CBRH) Load Impact Study This solution requires limited capital investment. It is ideal from a transformer loading st...

AI summary The proposed solution for the Cape Breton Regional Hospital involves minimal capital investment and is ideal for transformer loading, as the existing 111S-T61 circuit already supplies the hospital. However, the solution is less reliable because both the primary and secondary supplies would be fed from the same substation transformer, increasing the risk of a complete outage if 111S substation fails.

5.3 Alternative 3: Main supply via 111S-311 and Secondary supply via 6S-311 In this alternative, circuit 111S-311 would continue to be the primary supply for the Cape Breton Regional Hospital, although some reconfiguration would be require...

AI summary Alternative 3 proposes using circuit 111S-311 as the main supply and a new 12.5kV feeder from 6S-Terrace Street Substation (6S-311) as the secondary supply for the Cape Breton Regional Hospital. Both circuits would normally carry 50% of the load, but either must be able to handle the full load if the other fails. Upgrades and modifications are required, as shown in Figures 12 and 13.

6.2 Feeder Loading The fully loaded capacity of an NSPI 12.5 kV distribution feeder is presently the lower of the thermal capacity of the feeder circuit conductors, or 325 A (7 MVA). Under contingency operation, load on circuits can exceed...

AI summary The document discusses the capacity and loading of NSPI 12.5 kV distribution feeders, focusing on the limitations and modifications required for feeder 111S-311 to supply the Cape Breton Regional Hospital. It outlines conductor replacement and load distribution strategies to stay within operational limits.

6.2.2 Feeder 111S-312 Feeder 111S-312 experiences a typical winter peak loading of 105 A (2.3 MVA), which is well below the 325 A overload criterion. The circuit has capacity to offload other circuits and shares tie-points with 111S-311 an...

AI summary Feeder 111S-312 has a typical winter peak loading of 105 A (2.3 MVA), well below the 325 A overload criterion. The circuit has capacity to offload other circuits and shares tie-points with 111S-311 and 4S-321. The main three phase line uses 336 ASC conductor, capable of supplying the full hospital load.

6.2.3 Feeder 4S-321 Feeder 4S-321 experiences a typical winter peak loading of 200 A (4.3 MVA), which is well below the 325 A overload criterion. The circuit has capacity to offload other circuits and shares tie-points with 4S-332, 111S-31...

AI summary Feeder 4S-321 has a typical winter peak load of 4.3 MVA, well below the overload limit. To use it as the secondary hospital supply, the conductor would need upgrading from 4/0 ACSR to 336 ASC to handle increased capacity.

6.3 Circuit Voltage The Cymdist models of the distribution feeder circuits at 111S-Prime Brook, 4S-Townsend Street, and 6S-Terrace Street were modified to include the circuit switching and/or modifications needed to supply three-phase powe...

AI summary The Cymdist models for distribution feeder circuits at multiple locations were modified to provide three-phase power to a hospital. Load flow analysis showed that voltages remained within CSA limits under both normal and contingency conditions for each alternative studied.

6.4 Feeder Voltage Imbalance The voltage imbalance at the Cape Breton Regional Hospital site is shown for the main and secondary supplies after the circuit modifications at peak load conditions in the tables below. This value will vary wit...

AI summary The voltage imbalance at the Cape Breton Regional Hospital site is analyzed after circuit modifications at peak load conditions. Voltage imbalance is defined as the maximum deviation from the average phase-phase voltage divided by the average phase-phase voltage and is typically less than 3%.

Table 9: Alternative 1: Voltage Imbalance during Winter Peak Loading; 50% CBRH Load/Circuit Supply Voltage Imbalance at Cape Breton Regional Hospital Feeder Phase Voltage Voltage Average Imbalance Va 120.1 0.14% 111S-311 Vb 120.16 120.27 0...

AI summary The text presents three tables showing voltage imbalance data at Cape Breton Regional Hospital during winter peak loading under different alternatives. The data includes phase voltages, averages, and imbalance percentages for various feeders. The section also introduces a discussion on system short circuit levels.

The NSPI design criteria for maximum system fault capacity (three phase, symmetrical) is 195 MVA for the 12.5 kV distribution system (9000 A), and new equipment added to the 12.5 kV system must be designed to withstand fault levels of this...

AI summary The document outlines the NSPI design criteria for maximum system fault capacity on the 12.5 kV distribution system, specifying a limit of 195 MVA. It also notes that actual fault levels vary by substation and provides tables showing expected fault levels at the Cape Breton Regional Hospital site.

Table 15: Feeder reliability data (five year historical) Feeder Year All Events Excluding Major and Extreme Event Days CKAIDI CKAIFI CKAIDI CKAIFI 2020 0.05 0.05 0.05 0.05 111S-311 2021 0.04 0.02 0.04 0.02 2020 0.08 0.07 0.08 0.07 111S-312...

AI summary Table 15 presents historical feeder reliability data over five years, showing metrics like CKAIDI and CKAIFI for different feeders. The data highlights variations in interruption frequency and duration, with some feeders showing significant fluctuations, such as 4S-332 in 2020 having 2.00 interruptions per customer annually with a cumulative duration of 1.38 hours.

9.0 CONCLUSIONS This report presents the results of a Load Impact Study (LIS) for the 6.9MVA Cape Breton Redevelopment Project located in Sydney, Nova Scotia. After reviewing three alternatives, it is recommended that the primary and secon...

AI summary This section concludes a Load Impact Study for the 6.9MVA Cape Breton Redevelopment Project, recommending Alternative 2 for interconnecting the primary and secondary supplies to the NSPI Distribution System via specific circuits.

Secondary supply: 4S-332 reconfigurations: - 5. Reconductor Reservoir Road to the CBRH cable termination from 2/0 ACSR to 336 ASC. - 6. Close switch D3S22974 to Supply CBRH via 4S-332. - 7. Replace the existing double circuit poles along G...

AI summary This document outlines the proposed reconfiguration of the secondary supply system, including reconductoring, pole replacements, and flying tap installations. It also notes the estimated costs and the need for coordination to ensure proper protective device sizing. The report mentions alternative configurations based on substation requirements.

Preliminary Assessment Propos eed 1 2 7 M W D etrik utio n Co nnec tad I oad at y As aı 7 Nova S PC An Em OWER era Company Prep. By: Prep. By: NSPI 7-Oct-20 Page 1 of 4 Application Subm nitted E CBRH Load Customer General Location: Sydne S...

AI summary The document presents a preliminary assessment of a power application related to a commercial load connection at a regional hospital in Sydney, Nova Scotia. It includes details about the transformer, substation, and distribution system, as well as cost estimates for infrastructure upgrades.