The goal was to educate attendees on the Smart Wires approach to avoiding SSR and SSO while providing series compensation.
The discussion included Smart Wires' advanced power flow control device, a modular static synchronous series compensator (M-SSSC), capable of increasing or decreasing line impedance to increase transfer capacity.
Smart Wires suggested generators evaluate the use of M-SSSC to mitigate SSR and SSO in collaboration with TSPs.
The device is categorized under flexible AC transmission system devices and can emulate capacitance or inductance by injecting voltage in series with line current.
The M-SSSC is designed to provide real-time control and modular installation, with internal bypass protection circuitry and filters for managing transients.
A key point was the ability of M-SSSC to replicate an ideal sinusoidal waveform and integrate voltage injection in a more granular manner.
M-SSSC's operating characteristics focus on injecting voltage at fundamental frequency, differing from traditional series capacitors.
A case study from Latin America highlighted the device’s effectiveness in reducing negative electrical damping values compared to series capacitors.
Juan Botero detailed how the M-SSSC behaves similarly to the system when no compensation is present, showing no risks associated with M-SSSC installation for the case.
Smart Wires provided examples of successful applications, including a project in New York with Enernex, showing benefits in protection and footprint with the M-SSSC device.
The device showed no critical interaction with inverter-based resources or IBRs, though SSO studies are still recommended.
Cost estimates for projects using M-SSSC are variable but typically range between $5 to $15 million, based on project specifics.
The meeting highlighted the need for continued analysis of SSR scenarios, affirming the device's role in mitigating risks but not negating the necessity of SSO studies.
The presentation will be made available on the PLWG landing page.
Discussion concluded with the decision to table PGRR120 until May for further comments from ERCOT and DWG.
▶️5 - PGRR122 – Reliability Performance Criteria for Loss of Load
Jeff Billo introduced draft comments taking into stakeholder feedback. Main focus is determining appropriate loss of load limit via ongoing study.
Plans to present a loss of load study at the DWG meeting on May 15, which will help to inform the final number for allowable load loss.
Considered comments from LCRA and other stakeholders and made changes, including a new sentence on DC Tie load management and contingency planning.
Discussed NPRR1034's role in managing DC ties, allowing ERCOT to curtail DC Tie exports if frequency stability issues arise.
Proposals made for different treatment of large load interconnection studies versus general planning studies.
Jeff highlighted that PGRR122, for now, applies only to large load interconnection studies, but there may be further assessments depending on study results.
Concerns raised regarding retrofitting and constraints for existing loads or expanded facilities.
Stakeholders requested more clarity on criteria and how it impacts both new and existing interconnections.
Discussion on whether DC Tie loads are treated differently and possibilities to manage contingencies with solutions like transmission upgrades or load ride-through capabilities.
Emphasis on exploring additional approaches beyond PGRR122, including voltage ride-through standards and new ancillary services, for a comprehensive solution.
Stakeholders expressed concerns about the impacts of implementing PGRR122 and highlighted a need for clarity on how it maps with existing systems and facilities.
Need to further discuss the compatibility of PGRR122 with market mechanisms and broader planning efforts.
Proposal to table discussions until the next PLWG meeting after the planned presentation of the study results at DWG.
▶️6 - NPRR1272 – Voltage Support at Private Use Networks
ERCOT and Oxy had discussions about ERCOT's comments, which were posted the day of the meeting.
ERCOT's comments pertain to the interpretation of the voltage support obligation measured at the Point of Interconnection (POI) based on the net injection for the generator.
Concerns raised include the effect of colocated loads and their impact on the reactive power requirements and available reactive power for ERCOT, which may create fairness issues amongst generators.
ERCOT proposed the self-limiting concept, which Oxy expressed does not work for their situation.
There was a debate on whether a load balancing approach could eliminate Voltage Support Service (VSS) requirements for merchant generators.
Participants suggested that NPRR1272 remain under the purview of the PLWG until Oxy files further comments, though some believe it may eventually need to be moved to the WMS to discuss cost shifting implications.
Oncor expressed support for the self-limiting concept, acknowledging the need for further comments and discussions.
The topic was tabled for further discussion in the next meeting, potentially allowing more time for stakeholders to study the posted comments.
▶️7 - PGRR124 - ESR Maintenance Exception to Modifications
Eric Goff and Tesla representatives were expected to present but were not available.
ERCOT mentioned existing review processes for Megapack replacement including PGRR and large generation connection processes.
The PGRR109 process could be used to expedite the Megapack replacement.
Tesla is still examining arguments related to Megapack replacement.
Tesla plans to have internal discussions and reach out to customers and internal teams, such as the integration team.
Further internal discussions are planned between Tesla representatives and ERCOT.
The issue will be tabled for now, with follow-up planned with Eric Goff.
▶️8 - NPRR1274- RPG Estimated Capital Cost Thresholds of Proposed Transmission Projects
Robert Golen from ERCOT presented NPRR1274, focusing on adjusting cost estimate thresholds for RPG projects due to a 26% inflation increase since 2018.
Proposal suggests a 35% increase in tier categorizations for tier one, two, and three projects based solely on costs.
Martha Henson from Oncor supports the proposed adjustment but suggests that cost increases in transmission projects have been higher than general inflation.
Oncor highlighted factors not reflected in the general inflation index, such as costs for land, right-of-way, construction methodologies, temporary facilities, and specialty equipment.
Oncor noted an increase in EIR submissions due to projects exceeding current thresholds, advocating for a reassessment of these thresholds.
Oncor plans to file comments by May and requests to table the proposal until then.
Agreement to table the discussion until further comments are received in May.
The NPRR is linked to the resiliency project and criteria introduced by ERCOT last year.
The impetus for this NPRR stems from SB1281, which mandates ERCOT to conduct a grid reliability and resiliency assessment (GRRA) biennially.
The assessments must evaluate the impact of thermal and renewable generation availability and transmission outages under extreme weather scenarios.
According to the PUCT rulemaking, resiliency should be employed as an additional factor rather than a third criterion for project approval.
The NPRR aims to develop a process where the TSPs can leverage the assessment results to justify project approval.
Projects must address reliability issues identified in resiliency assessments and meet specific criteria related to thermal loading, voltage, and economic benefits.
Detailed discussions on how voltage limits and equipment limits should be managed to meet the criteria depending on different TSP practices took place.
Feedback and questions from stakeholders centered around the process and criteria, particularly the suggestion to adjust certain threshold values related to voltage and thermal overloads.
The TSPs will be responsible for submitting proposals to address identified issues, and ERCOT will ensure alignment with these evaluation criteria.
The new criteria will be integrated into Section 3.11.2 of the ERCOT protocols, which pertains to planning criteria.
