The Federal Energy Regulatory Commission gave preliminary approval last week to rules to protect the grid from geomagnetic disturbances and a final OK to a reliability standard for frequency response.

Geomagnetic Disturbances – EOP-010-1

The commission’s Notice of Proposed Rulemaking (RM14-1-000) endorsed Reliability Standard EOP-010-1, the North American Electric Reliability Corp.’s initial response to the commission’s July order calling for rules to close the “reliability gap” regarding geomagnetic disturbances (GMDs) caused by solar events. (See FERC Orders Rules on Geomagnetic Disturbances.)

Geomagnetically induced currents can flow through transformers and transmission lines, leading to increased reactive power consumption and disruptive harmonics that can cause system collapse.

The standard requires reliability coordinators and some transmission operators to institute operational procedures to mitigate the effect of GMDs. (The rule applies to transmission with a “transformer with a high side wye-grounded winding with terminal voltage greater than 200 kV.”)

Not covered are balancing authorities and generator operators although the second stage of the standards could apply to generators, FERC said.

In stage two, NERC must determine what severity GMD will constitute a “benchmark” GMD event. Covered entities will be required to assess the potential impact of such benchmark events on their equipment and systems.

Comments on the proposed standard will be due in 60 days after publication in the Federal Register.

PJM Procedures

PJM already has GMD operational procedures, which are detailed in section 3.7 of Manual 13.  The plan calls for PJM to notify generation and transmission members via the PJM All-Call system and Emergency Procedure posting application when the National Oceanic and Atmospheric Administration (NOAA) issues an alert for a potential GMD with a ranking of 5 or greater on the 9-point “K-index.”

Once a GMD has been confirmed, PJM dispatchers must operate the system under transfer limits determined from studies that modeled several scenarios, including the loss of the Hydro-Quebec Phase 2 DC line to Sandy Pond and the loss of generation at Artificial Island, the site of the Salem and Hope Creek nuclear plants.

Frequency Response – BAL-003-1

The BAL standard sets requirements for the provision and measurement of frequency response, which is not covered by current standards.

The rule establishes a minimum frequency response obligation for each balancing authority, provides a uniform calculation of frequency response, establishes frequency bias settings, and encourages coordinated automatic generation control (AGC) operation.

The commission ordered NERC to increase the violation risk factor for Requirement R1 — mandating minimum frequency response obligations — to high from medium.

“Without sufficient primary frequency control, a frequency decline may not be arrested in sufficient time to prevent instability, uncontrolled separation or cascading failures,” the commission wrote. “…The fact that one entity’s violation of Requirement R1 may be offset by the efforts of others is not a basis for ignoring or downplaying the substantial risk posed by inadequate frequency response.”

It also ordered NERC to remove references to performance of R1 by other entities: “We believe that violation severity levels for this requirement should be set so as to discourage particular responsible entities from `leaning on’ other entities to provide sufficient frequency response collectively to meet the relevant Interconnection Frequency Response Obligation.”

The commission directed NERC to submit two reports, one addressing the results and recommendations of a light-load case study of the Eastern Interconnection, and a second evaluating the use of the linear regression methodology for calculating frequency response and the availability of resources to meet the frequency response obligation.

The commission said the reports will indicate the effectiveness of the Reliability Standard in assuring sufficient frequency response is available to respond to system events and whether changes are needed.