N-1Report
30 passages
.................................................................................................... 20 15 3.2.5 Rate Base Procurement ...........................................................................................................
AI summary The document outlines sections covering rate base procurement, unit utilization forecasts, system impact studies, environmental regulatory requirements, and resource adequacy. Key themes include energy mix evolution, transmission service queues, renewable electricity mandates, and environmental policy updates.
..................... 41 27 6.0 Resource Adequacy ........................................................................................................... 44 28 6.1 Operating Reserve Criteria ...............................................
AI summary The document outlines sections related to resource adequacy, reserve criteria, and renewable energy capacity contributions in Nova Scotia's 2024 10-Year System Outlook, focusing on grid reliability, planning reserves, and renewable resource integration into the energy system.
1 7.0 Transmission Planning....................................................................................................... 51 2 7.1 System Description ...................................................................................
AI summary The document outlines transmission planning topics including system description, design criteria, bulk power system reviews, remedial action schemes, NPCC directory assessments, transmission life extension, interconnection requests, reliability ties, and specific studies like the Western Valley Transmission System Phase II and Hydrogen Load Impact Studies.
.6 Western Valley Transmission System – Phase II Study ............................................................ 57 14 7.7 Hydrogen Load Impact Studies .......................................................................................
AI summary The document outlines a 2024 10-Year System Outlook, including studies on transmission development, hydrogen load impacts, wind integration, and system inertia. It lists sections such as Western Valley Transmission Phase II, EMT studies for wind integration, and NSPI system inertia analysis, with the filing date of June 27, 2024.
Page 4 of 67 2024 10-Year System Outlook Non-Confidential 1 1.0 INTRODUCTION 2 3 NS Power is committed to supporting both provincial and federal targets to reach 80 percent clean 4 energy and phasing out coal generation by 2030. Great stri...
AI summary NS Power outlines its 10-Year System Outlook, aligning with provincial/federal clean energy targets (80% renewable by 2030) and the Clean Power Plan. The report assesses generation capacity, load forecasts, and regulatory compliance under Nova Scotia's electricity market rules.
Year NSR (GWh) Growth (%) 2017 10,873 0.6 2018 11,250 3.5 2019 11,077 -1.5 2020 10,723 -3.2 2021 10,902 1.7 2022 11,134 2.1 2023 11,131 0.0 2024F 11,490 3.2 2025F 11,409 -0.7 2026F 11,306 -0.9 2027F 11,347 0.4 2028F 11,416 0.6 2029F 11,448...
AI summary The document presents NSR (Net System Requirement) data from 2017 to 2034, showing fluctuating growth rates. NS Power forecasts peak demand using energy forecasts, weather models, and historical load factors, noting that customer growth, electrification, and EV adoption increase peaks, while DSM/DR activities reduce them. The 2022 Evergreen IRP's ELCC-adjusted DR contributions are included in firm peak calculations.
titutional (BNI) Curtailment, are included in the firm peak. 14 Customer growth, electrification of heating and increased EV sales increase the peak, while DSM 15 and DR activities reduce the peak. Compared to 2023, the near-term peak fore...
AI summary The near-term peak demand forecast is higher due to increased heating intensity from work-from-home activity and equipment usage, offset partially by DSM/DR initiatives. Customer growth, electrification of heating, and EV sales contribute to rising peak demand, while BNI curtailment and DSM/DR activities mitigate it.
Victoria Junction Light Fuel Oil 66 Total Combustion Turbine 231 Pre-2001 Renewables Independent Power Producers (IPPs) 25.7 Post-2001Renewables (firm) IPPs 64.3 NS Power wind (firm) Wind 14.5 Community-Feed-in-Tariff (firm) 8 7F IPPs 29.6...
AI summary The document corrects the Mersey system's firm capacity alignment with an ELCC adjustment, notes Annapolis out of service, Lingan Unit 2 in cold reserve until 2027, and specifies 18% firm capacity from ERIS/NRIS wind projects, referencing sections 3.1.2, 3.2.3, 3.2.4, and 6.3.
rt. 11 Ellershouse wind farm is owned by the Alternative Resource Energy Authority (AREA). 12 https://www.nerc.com/pa/Stand/Pages/Project2007-09-Generator-Verification.aspx DATE FILED: June 27, 2024 Page 12 of 67 2024 10-Year System Outloo...
AI summary The Ellershouse wind farm is owned by the Alternative Resource Energy Authority (AREA). The document also references a NERC generator verification page and introduces the '2024 10-Year System Outlook' section, which includes a subsection on Mersey Hydro.
Page 12 of 67 2024 10-Year System Outlook Non-Confidential 1 3.1.2 Mersey Hydro 2
AI summary The document references the '2024 10-Year System Outlook' section titled 'Mersey Hydro,' indicating a focus on hydroelectric resources within Nova Scotia's energy planning framework. The context suggests an analysis of Mersey Hydro's role in long-term system reliability and capacity planning.
3 The NS Power 2024 ACE Plan and Path to 2030 included sustaining capital investments in the 4 Mersey Hydro System (MHS) which will ensure safe and reliable water management throughout 5 the timeframe required to complete adequate prelimin...
AI summary NS Power's 2024 ACE Plan and Path to 2030 emphasizes sustaining investments in the Mersey Hydro System (MHS) regardless of redevelopment or decommissioning, citing economic benefits and contributions to renewable energy targets. The MHS provides 45.8 MW capacity and 220 GWh annually toward NS Power's goals, with updated reliability metrics reflecting its role in system planning.
24 rate (EFOR) stat for small hydro units was used as a proxy for the assumed DAFOR and the update 25 reflects the most recent five year average (2018 – 2022) published in August of 2023. 13 26 13 https://www.nerc.com/pa/RAPA/gads/Pages/Re...
AI summary The document references the use of Equivalent Forced Outage Rate (EFOR) statistics for small hydro units as a proxy for Derated Adjusted Forced Outage Rate (DAFOR), updated with a 2018–2022 five-year average. This methodology is tied to reliability assessments and cites NERC's August 2023 report.
Service 5662 5571 5377 5930 6065 6522 5957 4812 4045 4868 Hours 1 2 3.3.3 Steam Fleet Utilization Outlook 3 Unit utilization and reliability objectives have long been the drivers for unit investment planning. 4 Traditionally, in a predomin...
AI summary The document discusses the evolution of unit utilization planning at NS Power, emphasizing the need to account for variable renewable energy integration. It introduces the utilization factor (UF) as a new metric to better reflect the operational demands and flexibility requirements of generating units, considering factors such as capacity factor, operating hours, and asset health.
Page 24 of 67 2024 10-Year System Outlook Non-Confidential 1 Figure 9: Utilization Factor
AI summary The document presents a 10-year system outlook for 2024, focusing on the utilization factor as depicted in Figure 9. This figure is likely a key indicator for assessing system performance and planning for future energy needs.
2 3 The UF parameters are assessed to more completely describe the operational outlook for the steam 4 fleet and direct investment planning. The four parameters are described below. 5 6 • Capacity factor reflects the energy production cont...
AI summary The text discusses the importance of four parameters—capacity factor, service hours, unit cycling, and utilization factor—in assessing the operational outlook for the steam fleet and investment planning. It explains how these factors influence equipment reliability and maintenance strategies, particularly with the integration of variable-intermittent generation.
Page 26 of 67 2024 10-Year System Outlook Non-Confidential
AI summary This document provides a 10-year system outlook for 2024, outlining key considerations and projections related to the electricity system in Nova Scotia. It includes planning assumptions and strategies for managing demand, supply, and resource needs over the coming decade.
Progress 42 - D 754 24-Jan-24 Yarmouth 0.33 0.33 88W- Solar 30-Apr-24 SIS in N/A 314 Progress 43 - D 757 12-Feb-24 Halifax 0.74 0.74 103H- Solar 01-Oct-24 SIS in N/A 431 Progress 44 - D 740 08-Sep-23 Hants 0.25 0.25 20V- Solar 01-Jan-25 SI...
AI summary The document outlines progress on System Impact Studies (SIS) and Fuel Adjustment Clause (FAC) for renewable energy projects, including solar and wind generation. These studies are being expanded to include Electromagnetic Transient (EMT) Analysis to address system reliability and stability concerns due to the increasing share of variable renewable energy resources.
g the discussion paper and a period of industry engagement, ECCC released a proposed 13 frame 42 for a Clean Electricity Regulation under the Canadian Environmental Protection Act 41F 14 (CEPA) in July 2022, which will establish the perfor...
AI summary NS Power provided feedback to ECCC on the Clean Electricity Regulations, emphasizing the need for flexibility to maintain system reliability, meet customer demand during peak periods, and support wind resource integration.
Page 41 of 67 2024 10-Year System Outlook Non-Confidential 1 • NS Power’s modeling demonstrates that operating its emitting fleet in a peaking capacity 2 (with low annual capacity factors) supports system reliability while still reducing o...
AI summary NS Power's modeling shows that operating its emitting fleet as a peaking resource supports system reliability and reduces emissions. ECCC updated the CER on February 16, 2024, reflecting stakeholder feedback and proposed changes.
1 6.0 RESOURCE ADEQUACY 2 3 6.1 Operating Reserve Criteria 4 5 Operating Reserves are resources which can be called upon by system operators on short notice to 6 respond to the unplanned loss of generation or imports or unanticipated chang...
AI summary This section outlines NS Power's operating reserve criteria, including the need for 10-minute and 30-minute reserves to ensure system reliability. It references NPCC standards and the Interim Operating Agreement with NB Power, specifying reserve requirements and sources.
reserve is maintained to manage the 28 variability of customer load and generation. 29 45 https://www.npcc.org/program-areas/standards-and-criteria/regional-criteria/directories DATE FILED: June 27, 2024 Page 44 of 67 2024 10-Year System O...
AI summary The Planning Reserve Margin (PRM) is established to ensure sufficient resources are available to reliably serve firm customers. NS Power must comply with NPCC reliability criteria approved by the NSUARB, which require probabilistic evaluations to ensure loss of load expectation does not exceed 0.1 days per year.
rconnections with neighboring Planning Coordinator Areas, transmission 19 transfer capabilities, and capacity and/or load relief from available operating 20 procedures. 46 21 22 The PRM is a long-term planning assumption that is typically...
AI summary The document discusses the Planning Reserve Margin (PRM) as a long-term planning assumption, updated as part of the Integrated Resource Plan (IRP) process. NS Power confirmed a 20% PRM target as appropriate for long-term planning, which serves as a basis for minimum required firm generation to meet reliability criteria.
Winter Annual Wind Cumulative Marginal ELCC % Firm Capacity Period Capacity Added Capacity of Wind Applied to New Wind Contribution from (MW) (MW) Capacity New Wind (MW) Pre 2024 611 2024/2025 0 611 48 UARB Decision Letter, Generation Util...
AI summary The document references a UARB decision letter and studies related to generation utilization, optimization, and capacity value, including a 2019 study by Energy+Environmental Economics. It also includes a 2024 10-Year System Outlook, highlighting planning and resource planning efforts.
The criteria require the overall adequacy and security of 25 the interconnected power system to be maintained following a fault on and disconnection of any 26 single system component. 27 28 29 DATE FILED: June 27, 2024 Page 52 of 67 2024 1...
AI summary The text outlines criteria for maintaining the adequacy and security of the interconnected power system following a fault or disconnection of a single component, and mentions the 2024 10-Year System Outlook related to the Bulk Power System (BPS).
edure approved by the NSUARB, 25 elements classified as NS BES elements are required to adhere to all relevant NERC standards that 26 have been approved by the NSUARB for use in Nova Scotia. 27 DATE FILED: June 27, 2024 Page 53 of 67 2024...
AI summary The document outlines requirements for elements classified as NS BES elements to adhere to NERC standards approved by the NSUARB. It also references a 2024 10-Year System Outlook filing dated June 27, 2024.
1 7.2.3 2023 Bulk Electric System Exception Requests 2 3 Since the filing of the 2023 10-Year System Outlook Report, no new BES Exception Requests 4 have been received. 5 6 7.2.4 Remedial Action Schemes (RAS) 7 8 NS Power makes use of Reme...
AI summary The document discusses the absence of new BES Exception Requests since the 2023 10-Year System Outlook Report, the use of Remedial Action Schemes (RAS) by NS Power to maintain system stability, and the ongoing review of the NPCC Directory 1 Document by a working group, with voting on proposed updates scheduled for June 27, 2024.
24 Page 57 of 67 2024 10-Year System Outlook Non-Confidential
AI summary This document presents the 2024 10-Year System Outlook, a non-confidential report outlining the long-term planning and forecasting for the electricity system in Nova Scotia.
1 7.9 NSPI System Inertia and Strength 2 3 Conventional synchronous machine-based power generation supplies both active power and 4 reactive power, resulting in a high Short Circuit MVA (SCMVA) levels in most areas. SCMVA is 5 the ability...
AI summary The chunk discusses the impact of renewable inverter-based generation on system inertia and frequency stability. It explains that conventional synchronous machines provide inertia and frequency support, which is lacking in inverter-based resources like wind and solar. This may lead to frequency fluctuations and potential instability if not properly managed.
system stability will be maintained. Based on the PSS®E study to 28 date, there are concerns for the ability of the existing and future generation fleet to ride through 29 high RoCoF events. 30 DATE FILED: June 27, 2024 Page 60 of 67 2024...
AI summary The document discusses concerns regarding system stability and RoCoF (Rate of Change of Frequency) under high event conditions, and the impact of IBR (Inverter-Based Resources) on system strength and SCMVA (Short Circuit MVA) requirements. It mentions the use of EMT simulations and the potential need for additional equipment to maintain grid stability.
in local regions as there are some challenges with using 17 numerous IBR units to manage System Strength. This requirement will continue to be analyzed 18 as part of SIS and other grid studies. DATE FILED: June 27, 2024 Page 61 of 67 2024...
AI summary The document outlines the 2024 10-Year System Outlook, focusing on transmission development and the need for reinforcing the NS Power transmission system to ensure reliability and compliance with standards. Major projects are based on preliminary assessments and will be subject to further studies and approvals.
N-3NSPI (NSUARB) RIR-1 - RIR-18
92 passages
e amount of the year that at least 29 one pole is available for power transmission. Monopole availability provides sufficient 30 capacity for the transmission of the full NS Block. Date Filed: September 19, 2024 NSPI (NSUARB) IR-3 Page 1 o...
AI summary The document discusses monopole availability percentages for power transmission infrastructure, referencing Newfoundland and Labrador Hydro's (NLH) Resource Adequacy Plan and the Labrador-Island Link (LIL) reliability metrics. It highlights a 2.34% Equivalent Forced Outage Rate (EqFOR) for LIL and includes performance data for Muskrat Falls generating stations.
REVISION 2 - REDACTED - 2024-08-26.PDF (pub.nl.ca) 2 From NLH - Q1 2024 Report on the Rolling 12 Month Asset Performance in Support of Resource Adequacy - 2024-04-30.PDF (pub.nl.ca) Date Filed: September 19, 2024 NSPI (NSUARB) IR-3 Page 2...
AI summary NSPI states it assumes reduced peak capacity from the NS Block, aligning with NLH's EqFOR value of 5% for the LIL. Historically, the full 153 MW NS Block was delivered during system peaks in the past three years, as per NSPI's response to NSUARB's information requests.
2024 10-Year System Outlook Report (NSUARB M11764) NSPI Responses to NSUARB Information Requests NON-CONFIDENTIAL 1 Request IR-7: 2 3 On page 28 of 67, Figure 11 presents forecasted sustaining capital investments by unit in 4 graphical for...
AI summary NSPI responds to NSUARB's IR-7 request by revising sustaining capital investment forecasts, reorganizing data by plant, updating cost estimates, and noting Lingan 2's delayed retirement. Changes reflect revised utilization forecasts, condition assessments, and project-specific updates like POT gas conversion and LM6000 turbine fleet breakdowns.
demands placed upon NS Power’s generating units given the planned 27 utilization. The UF for each unit is evaluated by considering the forecast capacity factor, annual 28 operating hours, unit starts, expected two-shifting, and a qualitati...
AI summary The text discusses evaluating the utilization factor (UF) for NS Power’s generating units by considering forecast capacity factors, operating hours, unit starts, two-shifting, and asset health to better reflect their value to the power system.
1 (b) With respect to SIS Group 32, EMT analyses are designed to examine the following issues, 2 leading to corresponding findings: 3 4 • Inertia Requirements: 5 6 Inertia requirements have been specified to enable very high penetrations o...
AI summary The text outlines EMT analyses for SIS Group 32, addressing inertia requirements for high wind penetration, grid integration studies requiring updated PSCAD models, and facility validation against grid code. It highlights the need for multiple model iterations and collaboration with project teams.
Transmission System Interconnection Requirements (TSIR). There has been good 29 cooperation with all project teams and their vendors to get the models working and 30 meeting grid code and we will be looking to ensure that all models accura...
AI summary NSPI emphasizes cooperation with project teams to ensure models meet grid code, benchmark PSCAD models against commissioning results, and enforce compliance with TSIR. Deficiencies require remediation, including reactive power and inertia support equipment.
2024 10-Year System Outlook Report (NSUARB M11764) NSPI Responses to NSUARB Information Requests NON-CONFIDENTIAL 1 Request IR-12: 2 3 Reference NPCC Directory 1 and Directory 7 reviews, pages 54-55: 4 5 (a) NS Power noted that voting by N...
AI summary NSPI responded to NSUARB's information requests regarding updates to NPCC Directory 1 and 7. The updated Directory 1 passed with 94% approval, including clarifications on system boundaries, resource tripping, and fault treatment. Directory 7's review is expected to conclude in Q3 2024.
2024 10-Year System Outlook Report (NSUARB M11764) NSPI Responses to NSUARB Information Requests NON-CONFIDENTIAL 1 • Established Appendix H to include Technical Rationales. 2 3 • Alignment with NERC Standards: 4 • Table 3 Bus Section Faul...
AI summary NSPI updated the 2024 10-Year System Outlook Report by adding Appendix H with technical rationales and aligning with NERC standards via specific fault criteria. The NSUARB-led review of Directory 7, divided between two task forces, has progressed through draft revisions, with TFCP's work completed and TFSP's ongoing. Key milestones include open process reviews and final approvals by December 2024.
sibility or liability for the consequences of this document being used or relied upon by such Third Party. Any Third Party will, by such use or reliance, be taken to have confirmed its agreement to: (a) Indemnify MHI, its affiliates, and a...
AI summary Nova Scotia is transitioning to a cleaner energy future, aiming for 80% renewable energy by 2030. This shift will increase reliance on inverter-based generation, which poses technical challenges requiring careful planning and mitigation to ensure system reliability.
significant technical challenges that can be identified through careful planning and detailed studies, and mitigation measures implemented to ensure safe and reliable operation of the electric system. The system studies scope to understand...
AI summary The document outlines technical challenges in integrating 80% renewables into Nova Scotia's grid, emphasizing the need for EMT studies and mitigation measures. Key findings indicate that NSPI can incorporate renewables but will require grid support as legacy plants are phased out. Concerns are raised about the system's ability to handle high RoCoF events, potentially leading to cascade tripping.
lead to cascade tripping for loss of the NS/NB tieline under high import conditions. It should be noted that when NSPI stays connected to the Eastern interconnection the RoCoF will be low. • Survey NSPI existing legacy generation plants an...
AI summary The text discusses concerns related to frequency control and system strength, particularly focusing on the risk of cascade tripping under high import conditions. It highlights the need to assess NSPI's legacy generation plants and DER for RoCoF ride through capabilities, and recommends updates to interconnection requirements and grid code compliance.
erm and day ahead planning to maintain the SCMVA required for stable operation. The metric for the bullet above should capture the requirement for inertia with two 345kV tielines in service. • Until technology evolves such that all online...
AI summary The document discusses the need to maintain System Strength and Inertia in Nova Scotia's grid as renewable energy integration increases, emphasizing the importance of planning practices such as annual assessments of system inertia and strength, and the inclusion of factors like forced outages and maintenance in resource planning.
2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 5 of 60 Frequency Control and System Strength Assessment • Document and publish updated model requirements for Load and Generation customers. o It is recommended that NSPI p...
AI summary The 2024 10-Year System Outlook Report recommends NSPI update model requirements for load and generation customers, conduct system studies for western Nova Scotia, maintain SCMVA levels, and develop methodologies to estimate system strength and inertia as IBR resources are added to the grid. These actions aim to ensure grid stability and reliability.
Review and update all operating guidelines, as required, for the NSPSO in advance of next round of Transmission connected IBR (WEC, BESS, HDVC etc.) wind integration. EMT study will be required. As noted in the introduction, the study scop...
AI summary The document outlines the need to review and update operating guidelines for the NSPSO in preparation for the next round of transmission-connected IBR integration, including EMT studies. It also addresses black start restoration planning for the 2030 grid and mentions the need for frequency control and system strength assessments.
2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 7 of 60 Frequency Control and System Strength Assessment
AI summary The document is an attachment to the 2024 10-Year System Outlook Report, focusing on Frequency Control and System Strength Assessment as part of the Integrated Resource Plan (IR-15) submitted to the Nova Scotia Utility and Regulatory Board (NSUARB).
.4 Operability ....................................................................................................................... 42 7.2 Recommendations ....................................................................................
AI summary The document outlines the 2024 10-Year System Outlook Report, focusing on frequency control and system strength assessment. It includes appendices with SCMVA benchmark values and sensitive SCMVA buses for various years and scenarios, highlighting planning considerations for high IBR penetration and system reliability.
ficant technical challenges that can be identified through careful planning and detailed studies, and mitigation measures implemented to ensure safe and secure operation of the overall system. Large-scale penetration of renewable inverter-...
AI summary The document discusses technical challenges associated with the integration of large-scale renewable inverter-based generation into the power system, including reduced system inertia, lower short circuit levels, and potential impacts on system stability and security. Frequency control is highlighted as a critical aspect of maintaining system stability.
any instance in time. Generation is the electrical energy to supply the load at that instance in time. The generation can be within Nova Scotia or imported from a neighbouring utility. If the load (MW) and generation balance is not maintai...
AI summary This section explains how system frequency is maintained in the electricity grid, emphasizing the role of traditional synchronized generators in providing Synchronous Inertial Response (SIR) during disturbances. It highlights the importance of balancing load and generation to prevent frequency fluctuations and equipment tripping.
tem stability from a frequency perspective over the short duration. This short duration support allows online generation to adjust their MW output to balance the load and further stabilise the system. Newer renewable resources such as wind...
AI summary The text discusses the impact of inverter-based resources (IBR) on system frequency stability and the importance of system strength in maintaining grid stability. It highlights the difference between traditional synchronous machines and IBR in terms of frequency support and the need for control systems to simulate inertia and provide fast power injection.
stem extensions. If the frequency deviations can be well damped and RoCoF managed to allow the system load and generation to remain online, system stability will be maintained. 1.1.2 System Strength In an electric system, to be able to tra...
AI summary The document discusses system stability and strength in an electric system, focusing on frequency deviations, RoCoF (Rate of Change of Frequency), and Short Circuit Level (SCL) as key factors. It explains how maintaining voltage levels and managing short circuit currents contribute to system stability and reliability.
2 2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 12 of 60 Frequency Control and System Strength Assessment areas, and the system was considered “strong”. With the phasing out of synchronous generating units, there will b...
AI summary The document discusses the impact of phasing out synchronous generating units on system strength, noting that inverter-based resources (IBRs) provide significantly less support than traditional synchronous units. As IBRs increase in the generation mix, the system may become weaker, leading to voltage volatility and other operational risks.
generator shafts. • Wider area undamped voltage and power oscillations. • Mal-operation or failure of protection equipment to operate. • Prolonged voltage recovery after a disturbance. • Larger voltage step changes after switching capacito...
AI summary The text discusses the potential impacts of weak grid conditions on the operation of inverter-based resources (IBR), including voltage instability, harmonic distortion, and challenges in maintaining frequency and voltage control. It emphasizes the need for a strong grid at the point of interconnection (POI) for stable IBR operation.
Frequency Control and System Strength Assessment changes in voltage conditions at the POI are harder to follow and that could lead to unacceptable dynamic response of IBR. For IBR interconnection, the Short Circuit Ratio (SCR), the ratio o...
AI summary The document discusses the challenges of integrating Inverter-Based Resources (IBR) into the grid, particularly focusing on voltage stability and system strength. It highlights the importance of the Short Circuit Ratio (SCR) as an indicator of system stability and the risks of using multiple IBR units in weak areas, which can lead to control interaction and oscillations. Additional equipment may be required to manage voltage and system strength.
• IBRs are designed to operate to at minimum SCR. If the SCR is below the IBR design level, it may trip of during a system disturbance or lead to undesirable oscillatory modes. • To clear a system fault, protections relays operate to disco...
AI summary The text discusses challenges related to grid stability and frequency control, including the impact of Inverter-Based Resources (IBRs) on system strength, protection relay operations, and voltage management on the Nova Scotia Power Inc. (NSPI) grid. It highlights potential issues such as oscillations, instability, and voltage recovery difficulties.
4 2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 14 of 60 Frequency Control and System Strength Assessment The design of PE interfaced devices under low inertia and low SCR is technically challenging. To overcome these t...
AI summary The document discusses technical challenges related to frequency control and system strength in power systems with low inertia and low short circuit ratio (SCR). It highlights concerns such as reduced system stability, voltage control, fault ride-through capabilities, and control interactions, based on expert analysis and literature review.
es in close proximity, leading to unstable or poorly damped oscillations. • Impact from torsional oscillations, sub synchronous Interactions (SSTI), on thermal generator shafts. There has been much study and industry discussion on how to m...
AI summary The document discusses challenges related to frequency control and system strength in power systems with high penetration of renewables and power electronics. It highlights the need for careful planning and specialized studies, such as electromagnetic transient simulations, to address low short circuit ratios (SCR) and sub-synchronous interactions (SSTI) caused by the phasing out of thermal plants and the integration of renewable energy sources.
ystem Strength Assessment This is specifically the case for: • Weak in-feed (interconnection) points resulting in low SCR. NSPI has weak AC connections to the Eastern Interconnection. • Multiple dynamic devices in the local area: NS is pla...
AI summary The document discusses system strength and frequency control challenges for Nova Scotia Power Inc. (NSPI) as it integrates large-scale renewables. Key issues include weak in-feed points, low short circuit ratio (SCR), and N-1 contingencies that may affect voltage stability. The scope includes assessing inertia requirements, system simulations, and mitigation strategies for frequency and system strength.
1.2.2 System Strength • Perform a screening level assessment to benchmark 2023 SCMVA levels at 69, 138 and 230 KV buses. • Document minimum SCMVA at load sensitive locations. • Document minimum SCR at all Wind Plants, SVC and HVDC location...
AI summary The document outlines a system strength assessment for the 2024 10-Year System Outlook Report, focusing on identifying potential issues related to system strength, fault levels, and control interactions, and recommending measures such as synchronous condensers and BESS to maintain grid stability by 2030.
ear System Outlook Report NSUARB IR-15 Attachment 1 Page 17 of 60 Frequency Control and System Strength Assessment 2 Assessment Metrics and Methodologies The metrics and methodologies described below are utilized for this study. The assess...
AI summary The document outlines the assessment metrics and methodologies for evaluating frequency control and system strength in the context of integrating inverter-based resources (IBR) into the power system by 2030. It highlights the importance of system inertia and fast frequency response (FFR) from IBR for maintaining system stability following disturbances.
m vulnerable following system disturbances such as transmission system faults. For NSPI, system inertia and FFR from IBR is important from the point of view of two technical requirements: 1. System frequency response determines the system...
AI summary The document discusses the importance of system inertia and fast frequency response (FFR) from inverter-based resources (IBR) for maintaining grid stability and managing frequency excursions in Nova Scotia's future grid with increased renewable generation. It highlights the need to understand these requirements for system reliability and customer service.
8 2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 18 of 60 Frequency Control and System Strength Assessment For NSPI system design RoCoF, multiple scenarios for today’s system dispatch and configuration are assessed to de...
AI summary The document discusses frequency control and system strength for the NSPI system, noting the highest RoCoF documented and recommending further studies on RoCoF to determine maximum allowable values. It also highlights the impact of system inertia on IBR plants during LVRT and the need for some SIR to maintain performance with large-scale IBR.
pid voltage phase shifts. Until IBR technology is further advanced, some SIR will be required to maintain acceptable performance for an NSPI generation mix that includes large scale IBR. As mentioned previously, converter-based IBR generat...
AI summary The document discusses the challenges of maintaining system inertia and frequency response with the increasing use of inverter-based renewable generation (IBR) in Nova Scotia Power's (NSPI) generation mix. It outlines various methods to achieve inertial support, including synchronous generation, HVDC interconnectors, and fast frequency response from IBR plants and energy storage.
2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 19 of 60 Frequency Control and System Strength Assessment 2.2 System Strength As noted in Section 1.1.2, for the connection of additional IBR generation, the SCMVA is predom...
AI summary The document discusses system strength, particularly in relation to the connection of IBR generation. It explains that system strength is measured by the SCR, with classifications based on SCR values. A low SCR indicates potential issues such as fault recovery problems, unstable oscillations, and difficulty controlling bus voltage.
ed oscillations due to interaction with other plants near by. • Inability to operate to Grid Code requirements (fast power recovery following faults). • Difficult to control bus voltage. Accordingly, points of interconnection with an SCR l...
AI summary The text discusses technical challenges related to grid connection and system stability, particularly when integrating inverter-based resources (IBR) into the power system. It highlights issues such as system oscillations, inability to meet Grid Code requirements, and voltage control difficulties. It also emphasizes the importance of short circuit ratio (SCR) and system inertia in maintaining stability and fault ride-through performance.
ts and ultimately, the stability of the overall system. High SCR is an indication of the presence of synchronous machines in the local area and/or a strong, meshed transmission system. SCR, including Effective SCR and Weighted SCR, has bee...
AI summary The document discusses the importance of Short Circuit Ratio (SCR) in assessing grid stability and system strength when integrating new inverter-based resources (IBR) into the grid. MHI recommends conducting full grid studies and annual assessments to ensure frequency control and system strength requirements are met as renewable penetration increases.
ies compensated transmission lines in the local area. • Specific technology (vendor specific) and specific protection and control settings of the PE inverters and other plant equipment. • The MW rating or the MW output of the PE based plan...
AI summary The document discusses the impact of inverter-based plants on system strength and frequency control, emphasizing the importance of considering reactive power capacity and dynamic response under weak grid conditions. It highlights the need for detailed studies and the relationship between inertia constraints and system strength analysis.
culations are performed considering specific IBR connection location while the inertia requirements are estimated more at a system level. For System Strength Analysis, the following criteria is used: • Maintain SCR of at least 3 at existin...
AI summary The document discusses system strength analysis and frequency control criteria, focusing on maintaining system stability with IBR connections, SCR requirements, and assessing impacts of retiring units and new interconnections on system strength and power quality.
ew transmission load and generation connections, full study in PSS®E and PSCADTM is undertaken to identify any SCL conditions that may cause tripping or control interactions. 2.3 Iterative Assessment The initial assessment and metrics used...
AI summary The document discusses the iterative assessment of transmission load and generation connections, highlighting concerns about low SCMVA levels in certain areas of Nova Scotia, particularly when small hydro units are offline. This can lead to control interactions and reduced reliability, with recommendations to maintain or improve grid conditions.
ould cause a drop in reliability for customers. MHI recommends maintaining, and where possible improving the grid conditions to enable generation and customer load to ride-through system disturbances. As an example, with results of the fir...
AI summary The text discusses the impact of replacing traditional generation with IBR on grid reliability, highlighting the need for grid improvements to maintain system stability. It notes that while IBR can provide frequency support, System Strength support is still under development and not commercially viable in many cases.
sment in PSS®E For frequency control assessment, the Nova Scotia grid will experience the greatest frequency deviation and potential high RoCoF when it separates from the North American grid. • The critical dynamics contingency for inertia...
AI summary The document discusses frequency control assessment on the Nova Scotia grid, particularly focusing on the impact of separating from the North American grid. It highlights the critical contingency involving the loss of transmission lines between Nova Scotia and New Brunswick, and the potential for high RoCoF. Simulations were conducted to assess frequency response under various load conditions and maximum renewable energy integration.
run. Simulations were run iteratively to get the online synchronous generation dispatched to the minimum needed to maintain a stable and well damped frequency response for loss of the NB tie.
AI summary Simulations were run iteratively to determine the minimum online synchronous generation required to maintain a stable and well-damped frequency response in the event of a loss of the NB tie.
Simulation cases for the first stage studies focused on light load and peak winter load as most definitive in determining grid requirements for frequency control. Dozens of cases were run and those failing basic criteria in load flow were...
AI summary The text discusses simulation cases for grid frequency control studies, focusing on light load and peak winter load scenarios. Ten cases were selected after eliminating those failing basic load flow criteria, with details on thermal units and dispatch notes provided in Table 1.
ro resources are offline. Variations of FFR and inertia were simulated with the goal of taking inertia as low as possible while providing for well damped and stable frequency response. • The cases for winter peak are more complex. Small hy...
AI summary The document discusses simulations of frequency response and inertia variations, the complexity of winter peak cases requiring small hydro and thermal resources for stability, and the potential use of wind and BESS to reduce reliance on thermal units. Load flow and dynamic assessments were conducted for the loss of the NB tieline with high NS imports.
he load, while reducing the thermal units, new wind and BESS was added to the simulation cases. Load Flow and Dynamic assessment was performed for the loss of NB tieline with high NS imports. Case 5, with a low amount of inertia online, di...
AI summary The analysis discusses system reliability under varying thermal unit configurations and the impact of renewable energy and battery storage. Winter peak load cases showed voltage issues as thermal units decreased, and RoCoF exceeded 4 Hz/s in some scenarios. The Maritime Link with FFR can reduce inertia requirements, and future grid planning considers FFR from IBRs to support frequency control.
from IBRs as a potential source to reduce synchronous resources required to be online. IBR technology is evolving rapidly and both WEC and BESS may be able to support frequency in the 2030 timeframe. Notwithstanding the voltage issues and...
AI summary The document discusses the potential of Inverter-Based Resources (IBRs) to reduce the need for synchronous resources, particularly in the 2030 timeframe. It highlights the importance of frequency control and system strength, noting that iterative studies identified specific cases defining minimum inertia and Fast Frequency Response (FFR) requirements to maintain stable frequency response during loss of transmission lines to New Brunswick.
2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 26 of 60 Frequency Control and System Strength Assessment Table 2: Minimum Inertia and FFR Required for Frequency Control Total Case Dispatch Inertia Dispatch Notes (MW s) 5...
AI summary The document discusses the frequency control and system strength assessment for the 2024 10-Year System Outlook Report, focusing on inertia and Fast Frequency Response (FFR) requirements under various dispatch scenarios, including light and peak load conditions with maximum renewable energy integration.
901 MW new wind, 182 MW BESS Winter peak load has the highest inertia requirement for stable frequency response. The case dispatches for the peak load, with maximum renewables: • System load 2145 MW (2030 peak as forecast in 2020), includi...
AI summary The document discusses the impact of renewable energy and battery storage on frequency response and RoCoF in Nova Scotia's power system. It highlights the need for FFR as synchronous generation declines and renewable generation increases, referencing NERC's whitepaper on FFR and bulk power system reliability.
Reliability Needs” [1] provides a good overview of the fundamentals of frequency response and the FFR as a mechanism to replace a portion of the existing SIR required to maintain frequency and RoCoF. 17 2024 10-Year System Outlook Report N...
AI summary The document discusses the importance of frequency response and Fast Frequency Response (FFR) in maintaining grid reliability, highlighting the lack of standardized RoCoF (Rate of Change of Frequency) metrics. Simulations show varying RoCoF values under different load conditions, with the most severe RoCoF being 2.3 Hz/s under high load scenarios.
mports and three thermal units on for inertia support the highest load that can be served is approximately 1437 MW. That case, #11 in Table 3 below has a RoCoF of 2.3 for the most severe contingency. Table 3: Most Severe RoCoF, 2023 Grid C...
AI summary The document discusses the 2023 grid's frequency response and system strength, focusing on the most severe RoCoF (Rate of Change of Frequency) cases. Case 11, representing summer peak load, has a RoCoF of 2.3, which is higher than the existing grid's performance. The report references a GHD report suggesting a minimum RoCoF of ±2 Hz/s for stable frequency response.
18 2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 28 of 60 Frequency Control and System Strength Assessment Until further research or study dictates otherwise, sufficient inertia and FFR to maintain a RoCoF of under 2.5...
AI summary The document discusses frequency control and system strength in Nova Scotia's power grid, referencing the need for further study on RoCoF metrics and the capabilities of existing and new generation sources to maintain stable frequency during contingencies.
R grid support would be needed to reduce the RoCoF. For new generation connections, the NSPI Transmission System Interconnection Requirements [13] require facilities to ride-though a RoCoF of 4 Hz/s. With the study condition to maintain Ro...
AI summary The document discusses the need for grid support to reduce the Rate of Change of Frequency (RoCoF) under various load conditions. Simulations were run with different inertia and Frequency Response Reserve (FFR) configurations to assess their impact on RoCoF, showing that in most cases, the RoCoF exceeded the desired threshold of 2.5 Hz/s.
3.02 102 Peak Load 2404 0MW 3.27 103 Peak Load 3181 offline 2.48 The cases were re-dispatched, increasing inertia and FFR online to get RoCoF below 2.5 Hz/s as shown in Table 5. A significant increase in online inertia was required to meet...
AI summary The document discusses the re-dispatch of cases to increase inertia and FFR online in order to achieve a RoCoF below 2.5 Hz/s. Table 5 provides data on the total inertia and RoCoF for various cases, showing the relationship between load and inertia levels.
19 2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 29 of 60 Frequency Control and System Strength Assessment As BESS grid support capability is evolving rapidly, a test run was initiated on the 6 RoCoF cases with 200MW of...
AI summary A test run was initiated to assess the impact of BESS FFR support on RoCoF in various load cases. The results show a significant reduction in RoCoF, indicating that integrating BESS with FFR capabilities can reduce the inertia required for frequency control on the NSPI grid.
-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 30 of 60 Frequency Control and System Strength Assessment 4 System Strength Assessment in PSS®E A minimum level of System Strength is required for the power system to remain stable...
AI summary This section discusses the system strength assessment in PSS®E for the Nova Scotia grid, focusing on the minimum system strength required for stability during disturbances and the testing conducted using a full contingency set based on 2020 IRP studies. An average day dispatch was used as a benchmark for existing SCMVA.
its, ML, all hydro, biomass and PHP motors online. Wind is off to avoid counting the contribution of fault current from legacy wind as it does not support the grid during a system disturbance. Changing system load, different generation dis...
AI summary The document discusses the importance of monitoring System Short Circuit MVA (SCMVA) and Short Circuit Ratio (SCR) for grid reliability, particularly for sensitive facilities and existing wind plants. It outlines the need for future studies to ensure reliability is not compromised as the grid evolves.
4 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 31 of 60 Frequency Control and System Strength Assessment 4.3 Minimum SCR for Existing Wind Plants For existing facilities, the minimum SCR documented in the Interconnection Re...
AI summary The document discusses the minimum Short Circuit Ratio (SCR) for existing wind plants and system support requirements as the grid transitions to high renewables. It outlines the addition of reactor and capacitor banks to maintain post-contingency voltage within required ranges.
load cases, a small reactor was added in the Sydney area to bring post-contingency voltage to the range required. This proved adequate to maintain post contingency voltage for many scenarios. Load growth will usually increase the need for...
AI summary The document discusses the addition of a small reactor in the Sydney area to maintain post-contingency voltage and the potential need for static and dynamic reactive power support as load growth increases. It also examines SCMVA for sensitive buses and the role of synchronous condensers in providing grid support, particularly in the context of a second 345kV tieline to New Brunswick.
2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 32 of 60 Frequency Control and System Strength Assessment 4.4.3 SCR as a Screening Index SCR can be considered as a screening level index for a potential POI for IBR. Howeve...
AI summary The document discusses the use of Short Circuit Ratio (SCR) as a screening index for Inverter-Based Resources (IBR) at a Potential Connection Point (POI). It highlights that using SCR alone can lead to misleading conclusions about system strength and hosting capacity, especially when multiple IBRs are connected at the same POI.
IBRs would increase the more grid following IBRs are added to the system. As for calculation B, although not as optimistic as calculation A, it still overestimates the hosting capacity of the system. The hosting capacity of the system will...
AI summary The text discusses the impact of increasing grid-following inverter-based resources (IBRs) on system hosting capacity and the limitations of using SCR (Short Circuit Ratio) as a screening method. As IBR penetration increases, the SCR method becomes less accurate, requiring dedicated EMT studies for accurate assessments.
le maximum wind study, with and without a second 345kv tie to New Brunswick, is ongoing and will provide direction on the quantity and location of grid support mechanisms. 4.4.5 Stability Requirement When sufficient inertia, FFR and reacti...
AI summary The document outlines ongoing studies regarding grid stability and frequency control, including the development of an EMT model in PSCADTM by NSPI with MHI. These studies assess the need for grid support mechanisms and analyze stability requirements based on inertia, FFR, and reactive support criteria.
rios (load dispatch conditions, generation online, etc.) are implemented in the PSS®E case and the corresponding network conditions transferred to the PSCADTM cases using python based scripts. The general EMT study procedure is quite simil...
AI summary The text discusses the use of PSS®E and PSCADTM for simulating electromagnetic transients (EMT) and RMS dynamic simulations in power systems. It outlines the procedure for identifying critical contingencies based on screening studies and highlights illustrative results showing voltage waveforms and unstable oscillations at points of interconnection (POI) involving inverter-based resources (IBR).
undamental frequency oscillations. The Australian experience highlights the need to utilize wide area EMT models to replicate system observed issues that were not reproducible by any other means [15]. Increasing the short circuit level is...
AI summary The document discusses the challenges of integrating Inverter-Based Resources (IBR) into the grid, particularly in areas with low system strength. It highlights the need for advanced modeling techniques like EMT to understand system behavior and the potential of using IBR controls at the inverter level to improve system stability.
2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 38 of 60 Frequency Control and System Strength Assessment 5.4 Potential IBR Connection Issues The EMT analysis will review technical interconnection issues associated with l...
AI summary The document discusses potential issues related to the interconnection of Inverter-Based Resources (IBR) under weak grid conditions, particularly focusing on Fault Ride-Through (FRT) requirements. It highlights challenges such as limitations in Phase Locked Loop response and sensitivity of weak grids to voltage changes, which can affect the performance of PE inverter-based plants.
ak grid conditions. • Tripping of the plant will reduce voltage control capacity in the weak local area (where synchronous machines that can provide support are already limited or nonexistent). • Tripping of the plant will reduce power tra...
AI summary The text discusses the potential impacts of tripping power plants on voltage control and system stability, as well as the risks of control interactions (CI) from dynamic devices such as windfarms and HVDC systems. These issues are particularly significant in weak grid areas and can lead to instability if not properly managed.
acting exciters and PSS. • Interactions between windfarms. • Interactions between HVDC ties (Ex: Nemo & Nautilus in Europe) and windfarms. • Interaction with the rest of the AC power system. ERCOT has dealt with sub synchronous interaction...
AI summary The text discusses challenges in frequency control and system strength assessment, including sub-synchronous resonance (SSR) and synthetic inertia resource (SIR) interactions. It highlights difficulties in detecting SSR/SSCI events, the need for detailed EMT simulations, and the complexity of controller tuning. Mitigation strategies are vendor-specific and require collaboration.
ges are harder to design, and if not done judiciously, may impact robustness under normal operation. • Mitigation is vendor specific, and their participation is required in most situations. The Maritime Link HVDC, with newer VSC technology...
AI summary The document discusses challenges related to the integration of Inverter-Based Resources (IBRs) and Power Electronics (PE) into the grid, particularly concerning Sub-Synchronous Control Interactions (SSCI) and Sub-Synchronous Torsional Interactions. These interactions can lead to instability and require detailed studies to ensure compatibility with existing generation plants and control systems.
024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 41 of 60 Frequency Control and System Strength Assessment 5.4.4 Sub Synchronous Torsional Interaction Mechanical shafts of generators will undergo transient torque oscillatio...
AI summary This section discusses sub-synchronous torsional interaction (SSTI), focusing on how mechanical shafts of generators can experience transient torque oscillations due to network events such as system faults, transmission line switching, and series capacitor insertion. It also highlights the interaction between power electronic converters and generator shafts, which can lead to poorly damped mechanical oscillations, particularly in proximity to generating stations.
ractions with power electronic based devices (STATCOM, HVDC, wind) in close vicinity of generating stations in transmission system. Torsional interactions due to network resonance conditions: In addition to SSTI due to interactions with po...
AI summary The text discusses torsional interactions caused by network resonance conditions, particularly focusing on sub-synchronous resonance and its impact on thermal generators. It highlights risks to mechanical shaft-mass systems when natural frequencies align with sub-synchronous network resonant frequencies, potentially leading to unstable resonant conditions.
plore and model thoroughly as they will have high IBR penetration and solutions for System Strength issues include SVC, STACOM and other dynamic equipment. 5.4.6 RoCoF The addition of IBR and the subsequent phasing out of conventional gene...
AI summary The document discusses the impact of increasing IBR (Inverter-Based Resources) on the system's Rate of Change of Frequency (RoCoF) in Nova Scotia, particularly as conventional generation is phased out. This could affect the stable operation of IBRs using grid-following technology and the ability of legacy plants to remain online during frequency events.
rators may not be able to comply with the RoCoF ride-through requirements expressed in grid codes and that failure to ride-through could further exacerbate a RoCoF event. • ENTSO-E review of global experience with high RoCoF events suggest...
AI summary The text discusses concerns related to RoCoF (Rate of Change of Frequency) events, particularly the potential inability of generators and DER (Distributed Energy Resources) to comply with RoCoF ride-through requirements. It also highlights the need for a better understanding of RoCoF capabilities and the importance of grid interconnections to mitigate cascading events.
33 2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 43 of 60 Frequency Control and System Strength Assessment maintaining a required RoCoF for system design, fast acting jets, FFR or inertia forming machines could be dispa...
AI summary The document discusses frequency control and system strength assessment, highlighting the need to maintain a required rate of change of frequency (RoCoF) during system contingencies. It also addresses motor starting and transformer inrush considerations within the NSPI power system planning process.
on all new WECs to provide a frequency support contribution to the NSPI grid and that can include mechanical inertia from the turbine. 6.1.2 Grid Following and Grid Forming Inverters Typically, IBRs have been grid following – taking a refe...
AI summary The text discusses the need for frequency support from new WECs and addresses the challenges posed by the increasing number of grid-following inverters (IBRs) in Nova Scotia's power system. It highlights the potential for reduced system strength and the risks of cascading events if IBRs cannot maintain synchronism on a weak grid. Research into grid-forming inverters and virtual synchronous machine emulation is being explored to address these challenges.
ally in addition to staying online. This approach would have an IBR to operate in “grid forming” mode or with novel control concepts such as “virtual synchronous machine emulation”. 35 2024 10-Year System Outlook Report NSUARB IR-15 Attach...
AI summary The document discusses the potential of grid-forming inverters (IBRs) to stabilize the power system by emulating traditional synchronous machines. It highlights research and real-world examples, such as the Australian National Energy Market, that support the use of grid-forming inverters in high-renewables grids to ensure system strength and stability.
istribution network [21, 22]. The addition of frequency control, System Strength and high fault current from the grid forming BESS can allow higher levels of renewables to connect and operate. • The Maritime Link (ML), a VSC HVDC link betw...
AI summary The document discusses the role of frequency control and system strength in the distribution network, highlighting the benefits of grid-forming battery energy storage systems (BESS) in supporting higher levels of renewable integration. It also describes the Maritime Link (ML), a VSC HVDC link between Nova Scotia and Newfoundland, which provides frequency support and system stability during contingency events.
2024 10-Year System Outlook Report NSUARB IR-15 Attachment 1 Page 46 of 60 Frequency Control and System Strength Assessment 6.1.3 Fast Frequency Response Figure 6 in Section 7.1.2 demonstrates the ability of FFR from an IBR in damping a fr...
AI summary The document discusses the role of Fast Frequency Response (FFR) from IBRs, BESS, and HVDC in stabilizing the Nova Scotia grid during disturbances. It highlights the importance of BESS in managing renewable energy supply and mitigating stability concerns, as well as the potential use of synchronous condensers to enhance system strength and support high IBR penetration.
tation looks to provide better SCMVA support than brushless excitation. EMT models have been requested from vendors and assessment of the potential value to better support System Strength is underway. In addition to System Strength support...
AI summary The document discusses the importance of synchronous condensers and other system strength support measures, such as FACTS devices and transmission connections, in maintaining grid stability and frequency control as the penetration of inverter-based resources increases. EMT models are being assessed for their potential value in system strength support.
t consider the contribution of IBRs in the overall calculation of the SCMVA. 7.1.2 Minimum System Inertia and FFR The PSC study [23] performed for NSPI in 2019 documented the following: • A minimum of 3266 MW.sec of synchronous inertia wil...
AI summary The document discusses the contribution of Inverter-Based Resources (IBRs) to system inertia and Frequency Response Reserve (FFR), referencing a 2019 PSC study for NSPI. It notes that synchronous inertia requirements may vary based on system configuration and that NSPI will use RoCoF limits to manage inertia, though the metric's suitability for grids with high IBR penetration needs review.
r 2.5 Hz/s on a 500ms sample time for its most severe contingency. That said, this metric should be reviewed to determine if it is suited for a grid with IBR as a high percentage of online generation. There are many sources of inertia and...
AI summary The document discusses frequency control and system strength in Nova Scotia's grid, highlighting the role of the Maritime Link (ML) in providing Frequency Response Reserve (FFR) and arresting Rate of Change of Frequency (RoCoF). It notes that the ML's FFR can perform similarly to large synchronous machines and suggests additional Voltage Source Converter HVDC sources could enhance frequency support.
very quickly to help frequency recovery in Nova Scotia as it passed the triggering threshold. Seconds Figure 6: Maritime Link Frequency Response Based on the above, with new technology and FFR capability, the inertia requirement for stable...
AI summary The document discusses frequency control and system strength in Nova Scotia, highlighting how new technologies like FFR can dynamically meet inertia requirements. It notes that the minimum inertia requirement ranges from 2224 MW s to 3181 MW s, and FFR can reduce these values. The assessment focuses on frequency control, with additional SIR requirements depending on location.
control in line with the original PSC study. Depending on the location of the frequency support, additional SIR may be required online at specific locations to maintain SCMVA. 7.1.3 EMT Model Quality IBR control systems and operating modes...
AI summary The text discusses the need for high-quality EMT models to understand and evaluate the impact of IBR control systems on grid stability, especially as renewable energy penetration increases. It highlights the importance of robust models for developing project specifications and the potential need for updated guidelines and real-time data as grid conditions evolve.
time data needs may increase substantially and real time calculations for inertia and SCMVA at critical buses may need to be visible to Transmission Operations staff. • Distributed Energy Resources Increases in the total MW of DER and othe...
AI summary The document outlines potential challenges and recommendations related to system strength, distributed energy resources, protection and control, motor load customers, and transformation in the context of grid modernization and increasing renewable energy integration.
• Transformation Inrush issues may arise as noted in Section 5.4.8 and will be evaluated on a case-by-case basis as new plants and equipment are connected to the grid. 7.2 Recommendations The following recommendations are advised to enable...
AI summary The document discusses concerns regarding the integration of Inverter-Based Resources (IBR) in Nova Scotia's grid, particularly focusing on the need for stable and reliable integration. It highlights the risks of high Rate of Change of Frequency (RoCoF) events and recommends verifying network response through EMT simulations, reviewing existing generation plants, and updating transmission system interconnection requirements.
endations to facilitate current and future economic generation dispatch for increased renewables on the timelines in place for Nova Scotia: • Update IBR and inertia constraints for Plexos modelling. • Adequate frequency response is highly...
AI summary The document discusses the need to update inertia and frequency response constraints in Nova Scotia's grid planning to accommodate increased renewable energy. It emphasizes the importance of frequency response reserves (FFR) and synthetic inertia resources (SIR) as alternatives to traditional inertia, and highlights the need for a sliding scale for inertia/FFR based on system load. It also mentions the ongoing requirement for system strength metrics in resource planning.
line. At the present time, studies indicate that there is no hard limit on IBR penetration and dispatch if there is adequate frequency and System Strength support online. 7.2.3 Good Planning Practice Recommendations to implement good plann...
AI summary The text discusses planning practices for integrating renewables in Nova Scotia, emphasizing the need for annual assessments of system inertia and strength, updated model requirements for load and generation, and system studies for load growth and hydro availability. It also highlights the importance of maintaining SCMVA levels and addressing potential grid disconnections due to low system strength.
ower levels do not adversely impact NSPI customers. 7.2.4 System Operator Transition to High IBR Grid Recommendations to support the System Operator transition to a grid with high IBR online. 45 2024 10-Year System Outlook Report NSUARB IR...
AI summary The document outlines recommendations for transitioning the System Operator to a grid with high Inverter-Based Resources (IBR), including developing methodologies to estimate system strength and inertia, and reviewing operating guidelines. It also addresses black start restoration planning for the 2030 grid. A reference to a NERC report on Fast Frequency Response is included.
ntrol and System Strength Assessment 8 References [1] “Fast Frequency Response Concepts and Bulk Power System Reliability Needs”, NERC Inverter-Based Resource Performance Task Force, March 2020 [2] “Experiences with Wind Power Plants with...
AI summary The document provides references to studies and reports on system strength, frequency response, and the integration of renewable energy sources into power systems. It includes materials from NERC, AEMO, CIGRE, and various offshore wind projects, focusing on the impact of inverter-based resources and HVDC systems on grid reliability and stability.
of inverter-connected generation”, CIGRE WG C4.56 Technical brochure, 2022 [7] “Modelling and Simulation Studies to be performed during the lifecycle of HVDC systems”, CIGRE Working Group B4.38, 2013 [8] “A novel virtual synchronous machin...
AI summary The text references various technical documents and studies related to frequency control, system strength, and the integration of inverter-based resources into power systems, including guidelines from CIGRE, IEEE, and NERC.
eries, December 2022 [15] “Practical experience with mitigation of sub-synchronous control interaction in power systems with low system strength”’ Cigre Science and Engineering, Vol No. 21, June 2021 [16] Di Wu, Gangan Li, Milad Javadi, et...
AI summary The document references various studies and reports on power system stability and renewable energy integration, including analyses of sub-synchronous control interaction, system strength, and grid-forming energy storage systems. It also includes a reference to a stability study conducted by Nova Scotia Power for renewable integration.
requency Control and System Strength Assessment Appendix A: SCMVA Benchmark Values Tables redacted in document to be released to the public due to sensitive customer information. A-1 2024 10-Year System Outlook Report NSUARB IR-15 Attachme...
AI summary The document outlines the 2024 10-Year System Outlook Report, focusing on frequency control and system strength assessment. Appendices A, B, and C contain redacted tables related to SCMVA benchmark values, sensitive SCMVA buses, and SCR sensitive facilities, respectively. The report is part of a regulatory proceeding involving NSPI and the NSUARB.
2024 10-Year System Outlook Report (NSUARB M11764) NSPI Responses to NSUARB Information Requests NON-CONFIDENTIAL 1 Request IR-16: 2 3 In accordance with the Nova Scotia Wholesale and Renewable to Retail Electricity Market 4 rules, the 10-...
AI summary NS Power does not support expanding the 10-Year System Outlook report to include distribution system assessments, citing that Bill 404 and the Energy Reform (2024) Act will establish a Nova Scotia Independent Energy System Operator (NSIESO) responsible for resource and transmission planning, while NS Power retains distribution planning responsibilities.
1 Request IR-17: 2 3 In Section 6.2, Planning Reserve Criteria, NS Power quoted a portion of the NPCC reliability 4 criteria regarding probabilistic evaluation of resource adequacy and various factors that 5 need to be considered in that e...
AI summary NS Power states it has sufficient capacity to meet winter peak demand in 2024/2025, including 239 MW of reserve capacity, and expresses confidence in meeting demand during normal conditions. It also mentions that planning reserve margins are designed to handle abnormal situations such as unplanned outages or lower renewable generation.
units or transmission assets, etc. The amount of available reserve capacity for the Winter 29 2024/2025 means NS Power has sufficient capacity to serve firm customers uninterrupted Date Filed: September 19, 2024 NSPI (NSUARB) IR-17 Page 1...
AI summary NS Power has sufficient reserve capacity to serve firm customers uninterrupted during the Winter 2024/2025, as outlined in the 2024 10-Year System Outlook Report. The report was filed on September 19, 2024, as part of NSPI's responses to NSUARB Information Requests.