FAC-002-4 Interconnection Studies with an IBR Focus

The North American Electric Reliability Corporation (NERC) Reliability Standard FAC-002-4 ensures that interconnections of new or materially modified facilities do not adversely affect the reliability of the Bulk Electric System (BES). With the increased penetration of inverter-based resources (IBRs) such as solar photovoltaic (PV) systems, wind turbines, and battery energy storage systems (BESSs), the Standard was updated (effective January 1, 2024) to address the specific requirements and challenges posed by these resources within the FAC-002-4 framework.

FAC-002-4 focuses on conducting thorough interconnection studies to evaluate the impact of new or modified facilities on the BES. Requirement R1 of the Standard requires that these studies consider various operating conditions and system configurations to ensure that reliability criteria is met.

Steady-State Analysis

• Concern: Evaluate the impact of IBRs on voltage profiles, thermal loading, and power flows under both normal and contingency conditions.
• Approach: Utilize power flow simulations to analyze the steady-state performance of the BES with the inclusion of IBRs by assessing voltage stability, reactive power support, and thermal limits.

Short-Circuit Analysis

• Concern: Determine the impact of IBRs on fault currents and protection system coordination.
• Approach: Perform short-circuit studies to evaluate fault current contributions from IBRs by assessing the adequacy of existing protection schemes and identify necessary modifications.

Dynamic Stability Analysis

• Concern: Assess the transient and dynamic response of the BES with IBRs during and after disturbances.
• Approach: Conduct dynamic simulations to evaluate the behavior of IBRs during faults, frequency events, and other transient conditions by assessing the capability of IBRs to ride through disturbances and provide frequency and voltage support.

Model Validation and Data Requirements

• Concern: Ensure accurate representation of IBRs in interconnection studies.
• Approach: Require detailed IBR models and comprehensive data submissions from Generator Owners based on the Planning Coordinator’s definition of a qualified change per Requirement R6 of the Standard. These models should be evaluated against actual performance data and field measurements.

Coordination and Communication

• Concern: Facilitate effective coordination among relevant entities during the interconnection process.
• Approach: Establish clear communication protocols between Planning Coordinators, Transmission Planners, Transmission Owners, and Generator Owners by ensuring the timely exchange of information and collaborative resolution of potential reliability issues.

Compliance with Reliability Standards

• Concern: Ensure that IBRs comply with applicable NERC Reliability Standards, regional planning criteria, and facility interconnection requirements.
• Approach: Enforce adherence to all relevant Standards and criteria to maintain the reliability and stability of the BES. Monitor and document compliance throughout the interconnection process.

The integration of IBRs within FAC-002-4 is critical for maintaining the reliability and stability of the BES. FAC-002-4 ensures that IBRs are integrated into the grid in a manner that supports reliability by focusing on steady-state analysis, short-circuit analysis, dynamic stability analysis, model validation, coordination, and compliance. Adherence to FAC-002-4 will be essential for addressing the unique challenges and opportunities presented by the growing penetration of IBRs.