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PRC-019-2
Coordination of Generating Unit or Plant Capabilities, Voltage Regulating Controls, and Protection
PRC-019-2 requires Generator Owners, and Transmission Owners that own synchronous condensers, to coordinate voltage regulating system controls, including in-service limiters and protection functions, with equipment capabilities and the settings of Protection System devices. The coordination is repeated at least every five calendar years and within 90 calendar days after a change that affects it.
Who it applies to
- Generator Owners, and Transmission Owners that own synchronous condensers, with any of these applicable Facilities:
- An individual generating unit greater than 20 MVA (gross nameplate rating) directly connected to the Bulk Electric System.
- An individual synchronous condenser greater than 20 MVA (gross nameplate rating) directly connected to the Bulk Electric System.
- A generating plant/Facility of one or more units connected to the Bulk Electric System at a common bus with total generation greater than 75 MVA (gross aggregate nameplate rating). This includes individual generating units of dispersed power producing resources identified through BES Inclusion I4 where voltage regulating control for the facility is performed solely at the individual generating unit.
- Any generator, regardless of size, that is a blackstart unit material to and designated as part of a Transmission Operator's restoration plan.
- Category 2 Generator Owners of non-BES inverter-based resources are not subject to PRC-019-2, whose applicable Facilities are generating units, plants and synchronous condensers directly connected to the Bulk Electric System, unless a later revision of the standard includes them.
Key dates
- July 1, 2016: effective date. PRC-019-2 replaced PRC-019-1, and the PRC-019-1 implementation plan carries forward by reference.
- At least every five calendar years: repeat the R1 coordination; R1 allows at most five calendar years between coordinations.
- Within 90 calendar days of a change: after identifying or implementing a change that affects the coordination, perform it again (R2).
Source
NERC PRC-019-2 (standard page)October 29, 2026
Requirements
What each requirement asks for, in plain English.
R1 · Coordinate controls, limiters, capabilities and protection
What it means. At least every five calendar years, coordinate the voltage regulating system controls, including in-service limiters and protection functions (those installed and activated), with the applicable equipment capabilities and the settings of the applicable Protection System devices and functions. Assuming the normal automatic voltage regulator control loop and steady-state system operating conditions, verify for each applicable Facility that in-service limiters are set to operate before the Protection System so the generator is not disconnected unnecessarily, and that in-service Protection System devices are set to isolate or de-energize equipment to limit damage when operating conditions exceed equipment capabilities or stability limits. The standard does not require installing or activating any limiter or protection function.
Evidence an auditor expects. Dated documentation showing the coordination was performed. Section G of the standard gives examples: a P-Q diagram, an R-X diagram, an inverse time diagram, or equivalent tables, showing the equipment capabilities and the operating regions of the limiters and protection functions.
R2 · Re-coordinate after changes
What it means. Perform the R1 coordination again within 90 calendar days after identifying or implementing systems, equipment or setting changes that will affect it. These include, but are not limited to, voltage regulating settings or equipment changes, Protection System settings or component changes, generating or synchronous condenser equipment capability changes, and generator or synchronous condenser step-up transformer changes.
Evidence an auditor expects. Dated documentation of the coordination performed for each such change, showing the 90 calendar day interval was met.
For inverter-based plants
PRC-019-2 applies to inverter-based plants that meet its Facility thresholds, and Section G lists inverter overcurrent limits among the functions that may be coordinated; NERC RSTC implementation guidance for PRC-019 shows an inverter-based example built on inverter, collector bus and point of interconnection voltage coordination.
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