The adoption of a new IEEE standard could facilitate interconnection, says the head of EPRI – pv magazine USA

August 17, 2022William Driscoll

To make it easier to interconnect solar, wind and storage projects with the transmission grid, the Electric Power Research Institute’s (EPRI) technical director has recommended a “unified minimum capability set” for these inverter resources (IBR), which “could mean” adopting the new IEEE-2800 standard “as as soon as possible.”

EPRI is a utility-led research and development organization, and IEEE is a worldwide organization of engineers. IEEE published standard 2800-2022 earlier this year.

When project developers submit requests for interconnections without “very detailed, sufficient technical requirements, it is very difficult, if not impossible, to present any models that really represent these interconnections,” said Jens Böhmer, EPRI’s technical executive director of network operations and planning and integration. DER, online workshop organized by the Energy Systems Integration Group. “DER” stands for Distributed Energy Resources.

“Just agreeing on a technical set of minimum requirements can significantly reduce the expected performance,” Bomer said, which can “help inform some of the modeling.”

Böhmer raised the question of whether it is possible to submit tested models with an interconnection request in the event that plant equipment has not yet been selected. Here he again said that “perhaps standardization of performance through an IEEE standard could help solve this problem.”

Even before test and validation procedures are available for the IEEE-2800 standard, “a message from the signal industry” about future requirements to meet the standard “could be very welcome and helpful” to project developers, he said.

Boehmer said EPRI plans to submit comments to the Federal Energy Regulatory Commission that will “probably look similar” to his presentation on the notice of proposed rulemaking to improve the interconnection of generators.

Baumer also discussed “challenges and opportunities” at other stages of the relationship process. Feasibility studies, he said, often have limited validation of network strength metrics that could help determine “if at all and what types of modeling and system impact studies would be needed to reliably connect IBR.” He suggested that “perhaps some screening based on capacity maps of the site’s transmission hosting or rough measures of force could help inform what level of modeling detail might be required.”

Regarding subsequent nexus studies, Boehmer said that where a change in plant equipment may prompt a re-examination of the reliability study, “appropriate and sufficient and validated models based on actual equipment that will be used in the field may become important.”

Bomer provided a link to EPRI’s web page for validated publicly available models for various types of research.

Interconnection and reliability

Boehmer noted that his comments are aimed at addressing “today’s interconnection process” as well as reliability issues for inverter-based resources. The interconnection study process for large-scale renewables and storage is “very diverse” among regional grid operators and “somewhat behind,” he said, adding that the process lacks technical standards, requires different levels of technical detail for models and studies, and is often not automated. .

Boehmer also spoke of “significant reliability issues, particularly with solar PV,” pointing to resource outages as early as last year analyzed by the North American Electric Reliability Corporation (NERC). “These problems appear to be rooted in a mixture of insufficient inverter unit performance and inadequate plant design and configuration.” He recommended a pre-construction design assessment, which “we see used much more diligently in other parts of the world than here in the US.” After the plant is built, Boehmer discussed a possible “as-built” plant-level evaluation that could show that the installed plant is in line with what was designed and studied.

Training

“We don’t need to reinvent the wheel,” Bomer concluded. The issues he discussed are “new to North America,” but “it’s not new to many regions of the world.” North America “can use international developments,” he said, citing resources developed by the International Electrotechnical Commission (IEC), the European Association for the Cooperation of Transmission System Operators (ENTSO-e), and national standards developed in Germany and Australia.

Citing that knowledge, Boehmer said the Federal Energy Regulatory Commission “could fill in some important gaps that were not identified” in its notice of proposed rulemaking.