There is a lot happening in the IBR space right now, particularly in the context of the directives from the Federal Energy Regulatory Commission (FERC) and the regulatory changes at North American Electric Reliability Corporation (NERC). This article seeks to help distill down multiple topics into an easy-to-understand landscape overview of what is coming with respect to Order No. 901 and changes to the NERC Standards in this area.
Elevate Energy Consulting is here to help navigate this evolving landscape and stay up-to-date with ongoing regulatory changes.
Background: FERC Order No. 901
FERC issued Order No. 901 in October 2023 directing NERC to develop new or modified Reliability Standards that address reliability risks related to inverter-based resources in the following areas:
Data sharing
Model validation
Planning and operational studies
Performance requirements
NERC IBR Standards Work Plan
NERC subsequently filed an informational compliance filing in January 2024 outlining a standards development plan related to the Order No. 901 directives. Per the FERC directive, the NERC work plan lays out the projects must be submitted to FERC by November 2024, including:
IBR performance requirements including addressing frequency and voltage ride-through, post-disturbance ramp rate, phase lock loop synchronization, and other known causes of IBR tripping or momentary cessation (Project 2020-02)
Disturbance monitoring data sharing (Project 2021-04 Phase II)
Post-event performance validation (Project 2023-02)
Applicability to All "Registered IBRs"
Note that all the Standards revisions must be applicable to "registered IBRs," not only Bulk Electric System (BES) resources, per the FERC directives. This means that these revisions will apply to all of the IBRs that meet the impending revisions to Generator Owner (GO) and Generator Operator (GOP) Registry Criteria being made in the NERC Rules of Procedure. The registration criteria are being modified for both GO and GOP such that registration applies to:
"non-BES inverter-based generating resources that have an aggregate nameplate capacity of greater than or equal to 20 MVA delivering such capacity to a common point of connection at a voltage greater than or equal to 60 kV."
High Priority IBR Standards Projects
There are three "high priority" NERC Standards Projects currently underway specifically related to IBRs and they are in the spotlight of the ERO Enterprise and, more importantly, FERC given the mandates in Order No. 901. While FERC required very quick standards development timelines (i.e., development within about 1-year), all of these projects were already underway and required very little course correction to address any discrepancies between the Standard Authorization Requests (SARs) for each project and the directives in Order No. 901.
Here's a high-level overview of each of these projects and what Generator Owners of Registered IBRs should take note of...
NERC Project 2020-02: Generator Ride-Through Performance
NERC Project 2020-02 "Modifications to PRC-024 (Generator Ride-through)" is a direct outcome of over a dozen large-scale grid disturbances analyzed by NERC involving the unexpected tripping or reduction of power following normal grid faults. The drafting team has differentiated synchronous generation and IBRs in terms of ride-through requirements (a notable deviation from the submitted SAR) and is developing a new PRC-029 standard that will specifically address IBR ride-through performance.
The new PRC-029 is built on the laurels of IEEE 2800-2022; however, it does not adopt the standard directly since NERC has strongly articulated that it will not adopt IEEE standards within its regulatory framework. Therefore, GOs of IBRs will not only have to meet IEEE 2800-2022 due to local interconnection requirements; they will also have to demonstrate ongoing compliance to PRC-029. PRC-029, as it is being drafted, is applicable to owners and operators of IBRs - including dynamic reactive devices such as STATCOMs and SVCs as well as HVDC transmission facilities.
IBR GOs will need to ensure that they have their facility voltage and frequency protection set appropriately as well as ensure that the many other forms of protection will not also trip the facility within the performance curves (e.g., phase lock loop loss of synchronism, overcurrent protection, phase jump, rate-of-change-of-frequency, plant-level controller protection, etc.). The PRC-029 standard will also address post-fault ramp rates limits and dynamic active (and possibly reactive?) power response to a grid fault. Inverter, plant-level, and substation protection and controls are like "layers of an onion" that must be analyzed in concert with each other to ensure sufficient ride-through performance.
NERC Project 2021-04: Disturbance Monitoring
NERC Project 2021-04 "Modifications to PRC-002 - Phase II" is also a direct outcome of the NERC analysis of large-scale events because many facilities have historically lacked necessary data to understand the abnormal performance within their facility (see "Lack of Monitoring Data Available for Plants" section here). The drafting team is introducing a new PRC-028 standard specifically for registered IBRs. This new standard will require each applicable IBR facility to have the following:
Sequence of events recording for:
Circuit breaker position for main power transformers, the collector bus, and static and dynamic reactive devices
At least one IBR unit (i.e., wind turbine or solar or BESS inverter) down one of the longer collector feeders
Triggered fault recording data (64 samples/cycle) for:
High-side of main power transformer(s)
At least one IBR unit (i.e., wind turbine or solar or BESS inverter) down one of the longer collector feeders
Dynamic reactive devices
Continuous dynamic disturbance recording data (PPC recordings, PMUs, etc.) for the main power transformers
Note that all the SER, FR, and DDR data must be time synchronized to UTC with reasonable clock accuracy throughout. Data formats and sampling rates as well as submission requirements are specified in the new standard.
NERC Project 2023-02: IBR Performance Validation
NERC Project 2023-02 "Analysis and Mitigation of BES Inverter-Based Resource Performance Issues" seeks to ensure that any abnormal performance of IBRs are identified proactively and are addressed in a timely manner. The new PRC-029 focuses on ride-through performance and current injection of IBRs during grid events; the new PRC-028 focuses on ensuring data is available to conduct post-event analysis (i.e., "performance validation"). And the new PRC-030 focuses on ensuring that analysis is conducted by GOs of IBRs on a regular cadence.
Figure 1 provides a high-level overview of the process that is being proposed for IBR performance validation. The drafting team is proposing a process that includes the following:
Identify potential abnormal performance events: leverage the data available to ensure that (abnormal) performance of the facility is being adequately monitored and flagged for review. Note that the Balancing Authority, Reliability Coordinator, and/or Transmission Operator can also use their wide-area view to initiate a performance analysis if/when they observe a larger grid event involving IBRs.
Conduct post-event root cause analysis: Once a potential event is identified, the IBR GO will need to conduct a root cause analysis to determine whether the IBR performance was expected or unexpected. This involves gathering sequence of events data, fault recording data, plant controller data, inverter-level oscillography and fault code data, and any plant protective relay data to determine what happened and why it happened. This often involves engaging with the equipment manufacturers (OEMs) to gather some of this data. The draft standard proposes that this analysis be conducted within 45-days after the identification of an event.
Determine corrective actions and mitigations: After the root cause analysis and identification of unexpected performance, the IBR GOs will be expected to develop corrective actions to address the performance issue. This could involve making changes to control or protection settings, working with the OEMS, updating firmware, etc. This determination also has a proposed 45-day window.
Implement the corrective actions: Once the mitigations have been identified, IBR GOs will be required to implement mitigations and corrective actions within a reasonable (and documented) timeframe.
Figure 1: Conceptual Process Flowchart for Upcoming NERC PRC-030
Next Steps
These NERC Standards efforts are all on a fast-track process to completion, with strict FERC deadlines for final approval by November 2024. The standard drafting teams are working on refinements to the new standards and those will be solicited for industry comment and balloted by industry stakeholders. The IBR registration work is also underway, bringing smaller IBRs under NERC's jurisdiction (as ordered by FERC) and subsequently compliant with these mandatory and enforceable standards. FERC's directives have made clear that these standards will be applicable to this newly registered body through its orders and directives, so GOs of IBRs should take note and prepare proactively.
Reach out to Elevate Energy Consulting (info@elevate.energy) to discuss how we can support both engineering and regulatory compliance needs in this area. We have experts ready to support IBR owners and operators, system operators, balancing authorities, and reliability coordinators address these new challenges moving forward.
Comments