By Rich Heidorn Jr.

Generators under 20 MW will be required to ride through abnormal frequency and voltage events under a revised pro forma small generator interconnection agreement approved by FERC last week (RM16-8).

The commission already requires generators interconnecting under the large GIA to meet such requirements.

“It would be unduly discriminatory not to also impose these requirements on small generating facilities,” the commission said, noting that technology now available to small generators, such as smart inverters, gives them the capability to comply.

The revisions require small generators to not disconnect automatically or instantaneously from the transmission system for under- or over-frequency conditions and under- or over-voltage events. “The specific ride-through settings must be consistent with good utility practice and any standards and guidelines applied by the transmission provider to other generating facilities on a comparable basis,” the commission said.

The commission said its order reflected input received in response to its March Notice of Proposed Rulemaking. (See FERC Issues Reliability Orders on Relays, Small Generators.)

FERC said its action was warranted by the increase in grid-connected solar PV generation and generator interconnection requests driven by state renewable portfolio standards.

It cited NERC’s finding that “a lack of coordination between small generating facilities and reliability standards can lead to events where system load imbalance may increase during frequency excursions or voltage deviations due to the disconnection of distributed energy resources, which may exacerbate a disturbance on the bulk power system.”