IPWG: Recommended IBR Performance Requirements (PAC-2024-2) (20240502)

AES Clean Energy appreciates the opportunity to provide feedback on MISO’s implementation of IEEE 2800. AES supports these being applied on a prospective basis, and generally supports the application to DPP 2023 cycle projects and beyond. However, in our discussions with inverter manufacturers, we expect to have access to compliant inverters by 2026. AES recommends that MISO adopt similar exemption language as Phase 1, that would give resources an exemption of the requirements until June 1, 2026. Additionally, MISO should expand their definition of permissible technological changes to allow for the upgrade/modification of IEEE 2800 compliant inverters, even after GIA execution and these changes should not be deemed material or grounds to withdrawal of the project.

AES offers the following comments on specific subclauses specified on slide 22:

• Clause 5.1: Requiring the reactive power capabilities but not the utilization could lead to oversizing/underutilization of equipment. The specific capabilities the resource is expected to utilize should be specified in the GIA rather than in the tariff.
• Clause 5.2.2: The language is too vague and unclear on the definition of short circuit strength identification. MISO should provide more clarity and the range of values it expects the Transmission Provider or Owners to set in order for us to provide input on the feasibility of this requirement.
• Clause 5.2.2: It is AES’s understanding that a power factor of 0 active power is technically impossible. AES recommends that MISO to modify this language to be more technically sound.

On slide 11, AES opposes MISO’s proposal to set stricter requirements than identified in PRC-028-1 March 2024 Draft. AES recommends that MISO modify its proposal to require 30 days to provide data upon request, a data retention time of 20 days, and require one IBR unit per collector bus. Similarly, on slide 12, AES opposes MISO’s proposal to set stricter requirements for PMU data retention. This should align with PRC-028-1 and should be set at 20 days. The PRC 028 reflects significant feedback from the industry and is a reasonable compromise. MISO has not sufficiently justified why it needs to set stricter requirements, and AES recommends that they modify this part of the proposal to adopt PRC 028 requirements. For example, requiring inverter-level data on all units could add an estimated $2-4 million on each project. MISO has not provided adequate justification for why this granularity of data is necessary and why requiring one IBR unit per collector bus is not sufficient. However, we support MISO only applying this standard on new resources.

The Solar Energy Industries Association (SEIA) appreciates MISO accepting stakeholder feedback on proposed IBR requirements for phase II of IEEE 2800 adoption. MISO proposes to use the future NERC PRC-028 standard as the basis for measurement data requirements and is only calling out requirements stricter than what is anticipated in PRC-028. Rather than using the NERC PRC standard, SEIA urges MISO to align its requirements with IEEE 2800-2022 Clause 11.

PRC-028 may leave some gaps in fully leveraging the capabilities of modern inverter technology to capture data used for event analysis, performance monitoring, and model validation.[1] PRC-028 requires fault codes, fault alarms, and ride-through mode status at one IBR unit per collector bus connected at the far end of the feeders. This will greatly limit the ability to gather IBR unit-level fault codes, alarms, and status information. IBRs have much better capability today when monitoring is properly configured (i.e., avoiding overwritten data, etc.) to collect fault codes, status changes, trip settings, etc., at essentially every IBR unit in the facility. This is often configured by default by the equipment manufacturer. In many cases, the IBR unit oscillography data can also be enabled to capture IBR unit high speed measurement values, if needed.

Conversely, IEEE 2800-2022 Clause 11 covers monitoring data for IBRs. Table 19 requires inverter fault codes and dynamic recordings at all IBR units, with a more extensive list of required quantities that must be monitored and reported. It also requires that the data be retained for 90 days and any oscillography data must be five-second duration. IEEE 2800, which many entities are in the process of adopting, is more comprehensive than PRC-028 and will provide the data for demonstrating compliance with PRC-028. Therefore, leveraging the IEEE 2800 requirements to drive uniformity and consistency across system operator footprints is strongly encouraged.

For root cause analysis MISO suggests equipment manufacturers retain IBR unit level data, including fault codes and unit level signals as stated in Table 19 of the IEEE 2800 standard. MISO should not require IBR unit fault code and monitoring at unit level.  Rather, MISO should require equipment vendors to help with root cause analysis. Equipment fault codes cannot be deciphered by either developer or MISO without vendor support.

Some monitoring data gaps for IBRs proposed in PRC-028 could result in the inability to conduct meaningful analyses that mitigate risk, thereby potentially increasing cost to GOs and not providing the intended value and outcome for both GOs and grid reliability (i.e., reducing abnormal performance events at IBR facilities increases operating revenue and improves reliability for the BPS). In order to obtain more meaningful data from GOs, SEIA urges MISO to require data pursuant to IEEE 2800-2022 Clause 11.

[1] PRC-028 Clean Version, https://www.nerc.com/pa/Stand/Project202104ModificationstoPRC0022DL/2021-04_AB_PRC-028-1_Clean_03182024.pdf

At the May 2 IPWG meeting, MISO presented proposed Generator Interconnection Agreement Appendix G requirements pertaining to inverter based resources.  The MISO Transmission Owners (Owners) appreciate MISO advancing footprint wide requirements related to IEEE 2800. 

In response to specific items MISO is requesting feedback on, the Owners have the following comments:

MISO proposes requiring IBR plants have the reactive power capabilities outlined in IEEE 2800 Clause 5.1 but will not require utilization of those capabilities.  The Owners see value in these reactive capabilities being utilized now and would advocate for MISO to reconsider utilizing this capability.  The Owners note that without this utilization, more future transmission projects including reactive capability devices (e.g. inductors, STATCOMs, etc.) may be required.  However, if MISO cannot implement at this time, the Owners would ask for MISO’s implementation plan for utilization.

MISO proposes to use the March draft of the future NERC PRC-028 standard as the basis for measurement data requirements.  The Owners ask that MISO follow the development of the PRC-028 standard and make future adjustments to the measurement data requirements as needed to align with the final version of the standard. 

MISO proposes the use of phasor measurement units (PMU’s) to meet the Dynamic Disturbance Recording (DDR) requirements.  The Owners support this requirement assuming available PMUs can meet the technical specifications.  The Owners would also like clarification on the GIA Appendix G redlines using the term “fault recording” (FR) and if this is equivalent to the digital fault recording (DFR) in IEEE 2800.

MISO proposes to implement the IBR Appendix G requirements beginning with GIA’s resulting from the DPP-2023 Cycle.  The Owners support the implementation of these requirements as soon as practical and support applying them to the DPP-2023 cycle.

The Owners appreciate MISO’s engagement with the Owners in the development of these requirements and parameters to address decision points in the IEEE 2800 standard.

TO: MISO

FROM: The Entergy Operating Companies 

Subject: IPWG Recommended IBR Performance Requirements 

DATE: May 21, 2024

The Entergy Operating Companies ("EOCs")[1] appreciate the opportunity to provide feedback to MISO on the Recommended IBR Performance Requirements proposed by MISO during the May 2, 2024 Interconnection Process Working Group (IPWG). Entergy supports MISO’s implementation of the Phase 2 IEEE 2800 IBR Requirements, including Reactive Power capability, Voltage Control and Damping, Frequency Response, and Measuring and Monitoring. Entergy provides the following feedback and questions regarding the proposed IBR performance requirements.

Questions

Given that certain clauses of IEEE 2800 are referenced in the redlined version of the Tariff, do all Interconnection Customers have access to the P2800 standard to fully understand the requirements that they must adhere to?

With regards to the maximum step response time (i.e., 30 seconds or less), will MISO include in their stability assessment a review of post-fault stability plots for each IBR request to ensure that the maximum step response time is met (conformity review)?

Concerns

MISO indicates that while reactive power capabilities will be required, the utilization of those capabilities will not be required beyond those required by FERC Order 827. This position does not align with FERC Order 901 where FERC has ordered NERC to submit new or modified Reliability Standards to establish IBR performance requirements.

Besides FERC Order 827 and 901, certain aspects of reactive power capability utilization should be required as defined in NERC Standard VAR-002, such as automatic voltage control mode operation.

IEEE 2800 Sub clause 5.1 and 5.2.2

For Sub clause 5.1, the clause “high side of the generator substation” should be changed to “high side of the main power transformer at the collector substation” for clarity as typically there is no high voltage bus at the collector substation. The main power transformer high side has a direct line to the POI substation

For Sub clause 5.2.2, thirty seconds seems long for an IBR’s dynamic reactive power response to reach 90% of its final value in response to an event particularly if this criterion only applies to IBR’s located in areas of the system above a minimum short circuit strength threshold defined (i.e., stronger area of the system). FIDVR-related phenomenon can occur within 10-15 seconds following a fault and thus interconnected generation should help support system voltage in a timely manner during and after a fault. MISO indicates in their presentation that this requirement is subject to modification by the TO based on local system needs. However, this clarifying language was not included in the redlined Tariff.

[1] The Entergy Operating Companies are Entergy Arkansas, LLC, Entergy Louisiana, LLC, Entergy Mississippi, LLC, Entergy New Orleans, LLC, and Entergy Texas, Inc.