Topic:"Generation Grid Resources" in M11307

5. Fast Acting Capacity and Plant Retirement and Conversion The key new capacity resources seen across all of the model runs are 1) conversion of coal to heavy fuel oil (HFO) at relatively low annual capacity factor operation (459 MW, 3 pl...

AI summary The document discusses the key new capacity resources identified in model runs, including the conversion of coal to heavy fuel oil and gas steam, as well as new CT additions. The scenarios show significant variation in the need for these resources by 2030, 2035, and 2050, with the lowest CT capacity addition in hybrid peak and modified DSM scenarios under the No Atlantic Loop context.

Table 1. Modeling Scenario NPVRR Metrics Scenario Info, All Scenarios NZ 2035 Current Policy and TrendsAtlantic Loop Adjusted Atlantic Loop Timing CE1-E1-R1 AAT $ 18,700 $ 7,440 $ 26,140 $ 8,970 $ 8,970 NZ 2035 Current Policy and TrendsAtl...

AI summary The table presents various modeling scenarios with their corresponding Net Present Value of Revenue Requirements (NPVRR) metrics under different conditions, such as adjusted timing, wind integration constraints, and the inclusion of carbon capture or hydrogen. The scenarios explore the financial implications of different policy and infrastructure choices.

will be released to stakeholders for their review and NS Power will request feedback on the findings. will be evaluated by further study work (Updated Ac�on Plan page 7), including generator site– specific system impact studies for new var...

AI summary The document discusses the need for further study on the impact of adding synchronous condensers to the grid, as well as the evaluation of the Atlantic Loop's capital costs and energy import/export assumptions. NS Power agrees with Synapse on the importance of regional integration evaluations and updating modeling based on changes in assumptions.

port capacity. For clarity, the Company repeats that it is not planning for Atlan�c Loop availability by 2030. NS Power has demonstrated its commitment to remaining live to any poten�al import op�ons with neighbouring jurisdic�ons and will...

AI summary NS Power emphasizes its commitment to exploring import options and joint dispatch opportunities with neighboring jurisdictions, including an existing agreement with NB Power, and reaffirms that it is not planning for Atlantic Loop availability by 2030.

batery energy storage, PHP is concerned with further study that could poten�ally delay firm inprovince resources which will be required to maintain the reliability of the system, especially with the addi�on of significantly greater amounts...

AI summary The PHP emphasizes the need for expediency in studies related to battery energy storage, as delays could jeopardize the timeline for building firm peaking resources necessary for system reliability, especially with the addition of non-dispatchable renewables. The Evergreen IRP Update calls for 300 MW of new fast-acting generation by 2027. NS Power submits that constructing a combustion turbine is based on empirical evidence.

While batery storage does assist with the curtailment issues, wind integra�on and capacity, and addi�onal batery storage is called for in the No Loop scenarios, NSPI lays out in some detail in its responses to stakeholder comments (see pag...

AI summary The text discusses the limitations of battery storage in replacing fast-acting generation and the need for synchronous condensers to support wind integration by 2030. NSPI explains that battery storage has duration limitations and must be supplemented with other resources during peak periods. PHP highlights the addition of 80 MVA of synchronous condensers for wind integration.

This document outlines the general planning criteria and recommendations to specifically address large scale integration of Inverter Based Resources (IBRs) such as wind generation and grid scale battery projects. Results and observations f...

AI summary The document outlines planning criteria and recommendations for integrating large-scale Inverter-Based Resources (IBRs), including wind generation and grid-scale battery projects, based on results from first-stage assessments and studies.

1.1.2 System Strength In an electric system, to be able to transmit power to the customer load, the voltage level on the transmission grid must be maintained within a specific range. When there is a system disturbance,such as lightning str...

AI summary The document explains system strength in electric grids, emphasizing the role of Short Circuit MVA (SCMVA) and the impact of replacing synchronous generators with Inverter-Based Resources (IBRs). Synchronous machines historically provided high SCMVA, but IBRs offer only 10-20% of that support, weakening system stability and increasing voltage volatility during disturbances.

gineers exercise sound engineering judgement when assessing SCR values. The specific nature of potential issues would depend on several other factors that are not fully illustrative though SCR values: - Harmonic impedance (resonance charac...

AI summary The text discusses the importance of considering various factors when assessing Short Circuit Ratio (SCR) values for inverter-based plants, including harmonic impedance, series compensated transmission lines, and reactive power capacity. It highlights the limitations of using MW ratings for SCR calculations and suggests considering MVAR ratings in certain cases.

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) such as Wind Energy Conversion (WEC) and Battery Energy Storage Systems (BESS) to reduce the need for synchronous resources in the 2030 timeframe. It also highlights the minimum inertia and Fast Frequency Response (FFR) requirements identified through iterative studies for maintaining stable frequency response during light load and winter peak load scenarios.

Table 2: Minimum Inertia and FFR Required for Frequency Control Case Dispatch Total Inertia (MW s) Dispatch Notes 51 Light Load 1044 TUC5, TUC6 & ML 50 MW FFR, Biomass on / existing wind 52 Light Load 1102 TUC2, TUC6 & ML on no FFR, Biomas...

AI summary The table outlines minimum inertia and FFR requirements for frequency control under various load conditions, with winter peak load showing the highest inertia requirement due to the integration of maximum renewable energy sources.

4.3 Minimum SCR for Existing Wind Plants For existing facilities, the minimum SCR documented in the Interconnection Request will be maintained. If no minimum ride through value has been documented for an existing facility, NSPI will target...

AI summary The document discusses maintaining a minimum Short Circuit Ratio (SCR) of 3 at the low side customer bus for existing wind plants in Nova Scotia, unless a different value is specified in the Interconnection Request. SCR values are benchmarked at the NSPI Transmission Level voltage for analysis of future dispatch patterns.

4.4.3 SCR as a Screening Index SCR can be considered as a screening level index for a potential POI for IBR. However, engineering judgement should be exercised when making screening level conclusions based on such indices. This can be illu...

AI summary This section discusses the use of Short Circuit Ratio (SCR) as a screening index for determining the suitability of a Point of Interconnection (POI) for Inverter-Based Resources (IBR). It highlights limitations of SCR calculations when multiple IBR projects are connected to the same POI, emphasizing that hosting capacity should be based on combined IBR sizes and that EMT studies are necessary for high IBR penetration scenarios.

4.4.4 IBR SCR As noted in Section [4.4.3,](#page-31-0) SCR has limitations in its usefulness as a screening metric for the connection of additional IBR. However, it is still a measure of a wind facility's ability to ride through system eve...

AI summary The document discusses the Short Circuit Ratio (SCR) as a metric for assessing the ability of Inverter-Based Resources (IBR) to ride through system events. It outlines current SCR ranges, the intent to maintain SCR at the Point of Interconnection (POI) for legacy IBR plants, and the need for system studies to determine grid support requirements as the grid evolves.

5.4 Potential IBR Connection Issues The EMT analysis will review technical interconnection issues associated with large scale connection of IBR.

AI summary This section discusses the potential technical interconnection issues related to the large-scale integration of Inverter-Based Resources (IBR) into the power system, focusing on the need for an Electromagnetic Transient (EMT) analysis.

5.4.3 Sub Synchronous Control Interaction When an IBR is connected to a network, the voltage and phase at the IBR terminals are each sensitive not only to the inverter output but also to the output from other nearby IBR projects or FACTS d...

AI summary The document discusses Sub-Synchronous Control Interaction (SSCI) when Inverter-Based Resources (IBRs) are connected to a network, particularly near series compensated lines. It highlights the potential for negative damping effects from IBRs, such as Type 3 wind units, and notes that Nova Scotia Power Inc. (NSPI) is considering series compensated lines in some studies, requiring SSCI analysis.

SSTI due to interaction with power electronic converters: Power electronic converters and their controls can interact with the natural modes of generator shafts and give rise to poorly damped mechanical shaft oscillations. A main objective...

AI summary This section discusses the potential for Sub-synchronous Torsional Interaction (SSTI) caused by the interaction between power electronic converters and generator shafts, leading to poorly damped mechanical oscillations. The focus is on investigating these impacts through Electromagnetic Transient (EMT) studies, particularly in proximity to generating stations and transmission systems.

5.4.6 RoCoF The addition of IBR and the subsequent phasing out of conventional generation in Nova Scotia has potential to adversely impact the system RoCoF. This in turn will have impacts on the stable operation of IBRs that are based on g...

AI summary The integration of Inverter-Based Resources (IBR) in Nova Scotia's grid, along with the phase-out of traditional generation, may negatively impact the system's Rate of Change of Frequency (RoCoF). This could affect the stable operation of IBRs and legacy plants during frequency events. Manitoba Hydro International (MHI) recommends surveys and EMT simulations to better understand RoCoF impacts and ensure system reliability.

5.4.7 Motor Starting Industrial motor starting has been a critical consideration of the NSPI power system planning process. With the expected penetration of IBR, EMT study-based verification may be required in specific situations. Data has...

AI summary Industrial motor starting is a key consideration in NSPI's power system planning, especially with the increasing use of IBR. EMT studies may be needed to assess potential adverse impacts on motor starting capabilities, and data from large manufacturing plants in Nova Scotia is being used to develop plant models for this purpose.

6.1 IBR Control System Design Fault ride-through, control interactions, RoCoF control, and low frequency oscillations are the primary concerns. The most cost-effective solution, where possible, may be the re-tuning of control settings or a...

AI summary The design of IBR control systems focuses on addressing fault ride-through, control interactions, RoCoF control, and low frequency oscillations. Re-tuning control settings or adopting alternate control strategies, such as active or reactive power control, is highlighted as a cost-effective solution. IBR's fast response can replace inertia from traditional plants.

6.1.2 Grid Following and Grid Forming Inverters Typically, IBRs have been grid following – taking a reference signal from the grid and matching output to synchronize with the grid angle and voltage. System voltage and frequency is maintain...

AI summary The document discusses the transition from grid-following to grid-forming inverters in Nova Scotia's power system. As synchronous generators are retired and IBR penetration increases, system strength may decline, leading to synchronization issues. Grid-forming inverters, which can emulate synchronous machines and control voltage and frequency, are being explored as a solution to maintain grid stability in a high-renewables environment.

6.1.3 Fast Frequency Response [Figure 6](#page-49-0) in Section [7.1.2](#page-48-0) demonstrates the ability of FFR from an IBR in damping a frequency deviation for a system disturbance. FFR from HVDC, BESS and other fast acting devices wi...

AI summary This section discusses the role of Fast Frequency Response (FFR) from Inverter-Based Resources (IBR), HVDC, and Battery Energy Storage Systems (BESS) in stabilizing frequency deviations in Nova Scotia's power system during generation disturbances. These systems offer flexibility in rapidly adjusting power injection or consumption based on the state of charge.

6.2 BESS BESS can support the management of the energy supply in a renewable energy dominated NSPI system. Additionally, with appropriate specifications, the fast-acting nature of BESS inverters can also be used to mitigate stability relat...

AI summary Battery Energy Storage Systems (BESS) are highlighted for their ability to manage energy supply in a renewable energy-dominated Nova Scotia Power Inc. (NSPI) system and mitigate stability concerns through fast-acting inverters. They are considered a strong near-term candidate for providing grid-forming and virtual synchronous machine response.

6.3 Synchronous Condensers The addition of synchronous condensers at selected locations in an electrical system is an effective technical solution to facilitate high IBR penetration. It is expected that additional synchronous support will...

AI summary Synchronous condensers are being considered for installation in the NSPI grid to support system strength and accommodate high IBR penetration. Research is ongoing with vendors to understand design options, and EMT models are being assessed for their value in enhancing system stability and frequency response.

6.5 Fast Acting Synchronous Generation As the penetration of IBR increases, many of the larger synchronous thermal units will be phased out or operating infrequently. To plan for peak load periods when sufficient wind and imports are not a...

AI summary As the use of inverter-based resources (IBR) increases, traditional synchronous thermal units may be phased out. To address potential energy shortfalls during peak load periods, fast acting synchronous generators will be deployed. These generators can also function as synchronous condensers to support the local grid when not generating power, increasing their overall value.

7.1.1 IBR for Frequency and System Strength Support A decade ago, IBRs were not considered to provide good frequency and System Strength support. However, this is changing due to the introduction of new frequency and voltage control strate...

AI summary The text discusses how Inverter-Based Resources (IBRs) can now provide frequency and system strength support through new control strategies. IBRs must operate below maximum power to allow for output adjustments, and BESS can also contribute. However, IBR contributions to short-circuit MVA should be carefully considered for system strength assessments.

• Distributed Energy Resources Increases in the total MW of DER and other behind the meter generation will pose a risk as it may not have the associated System Strength to remain stable during system disturbances. As IBR generation sources...

AI summary The increase in distributed energy resources (DER) and behind-the-meter generation may pose stability risks due to insufficient system strength during disturbances. Inverter-based resources (IBR) not controlled by the System Operator require detailed study, as they are not currently modeled in system studies.

7.2 Recommendations The following recommendations are advised to enable large scale integration of Inverter Based Resources in Nova Scotia.

AI summary The text outlines recommendations aimed at enabling the large-scale integration of Inverter-Based Resources (IBR) in Nova Scotia, highlighting the importance of such integration for the energy sector.

7.2.1 Stable and Reliable Integration Recommendations to facilitate the integration of renewables on the timelines in place for Nova Scotia: - Based on study to date, there are significant concerns for the ability of the existing and futur...

AI summary The document outlines recommendations to ensure stable and reliable integration of renewable energy sources into Nova Scotia's grid. Key concerns include managing high RoCoF events, updating interconnection requirements, and addressing grid support needs as synchronous plants retire. Studies and system upgrades are recommended to mitigate risks of cascading tripping and maintain grid reliability.

7.2.5 Black Start Restoration Planning Recommendation to support restoring a blacked out grid: • Review and assess potential Blackstart options for the planned 2030 grid, considering the generation mix available a that time.

AI summary The text recommends reviewing and assessing potential Blackstart options for the planned 2030 grid, taking into account the generation mix available at that time.