PRC-030-1 – Unexpected Inverter-Based Resource Event Mitigation

The North American energy industry is continuously diversifying to reduce dependence on traditional electrical systems. Today, we have choices such as wind, geothermal, utility-scale solar, battery energy storage systems, and more. Many modern renewable and storage technologies, particularly wind, solar PV, and battery storage, are classified as Inverter-Based Resources (IBRs).

These technologies provide cost, environmental, and operational benefits. However, they are prone to reliability risks. Most of these risks occur during and after grid disturbances. To address such challenges, the North American Electric Reliability Corporation (NERC) introduced the PRC-030-1 reliability standard. PRC-030-1 was filed by NERC on October 8, 2024. Subsequently, it was approved by the Federal Energy Regulatory Commission (FERC) as part of the IBR reliability standards package developed in response to FERC Order 901. This reliability standard is designed to mitigate unexpected and post-disturbance events associated with inverter-based resources.

What is PRC-030-1

PRC-030-1 is a reliability standard developed by NERC that focuses on the post-disturbance performance during unexpected events. It helps conduct risk event analysis and take corrective actions to fix the issue and/or minimize damage to the Bulk Electric Systems (BES). It also establishes requirements for Transmission/Generator Owners and Operators to analyze, assess, identify, and mitigate risks posed by unexpected or abnormal behavior of Inverter-Based Resources (IBRs). As a result, it improves system reliability through coordinated actions, including data sharing, analysis, and corrective measures.

What PRC-030-1 Covers

The PRC-030-1 mandates the following four major actions for operators and owners:

1. Event Identification (R1): Establishing a documented process for specific, sudden, and significant drops in power output. This typically applies to losses of 20 MW or more, or to 10% of gross nameplate capacity within 4 seconds.
2. Event Analysis (R2): Within 90 days of an event, the root cause must be identified. This includes identifying the cause of unexpected performance, assessing the facility’s voltage/frequency ride-through behavior, and determining whether the issue affects other IBRs in the fleet.
3. Corrective Action Plans (R3): If a performance issue is identified, a CAP must be created, or a technical justification (if no action is taken) must be provided within 60 days of analysis and submitted to the appropriate reliability authorities.
4. Mitigation and Implementation (R4): The operators/owners must implement a corrective action plan to prevent future reoccurrences.

How PRC-030-1 Helps Mitigate Unexpected IBR Events

The PRC-030-1 enables transmission and generation entities to promptly respond to unexpected BES disturbances. It enables the involved parties to share data and jointly analyze events in which IBRs responded unexpectedly, such as a momentary cessation or failure to recover after a disturbance. The information is then used by the responsible entities to develop and implement corrective or mitigation actions. The Corrective Action Plan and mitigation strategies include:

• Control setting changes
• Model improvements
• Operational adjustments.

The actions described significantly reduce the likelihood and severity of similar IBR events in the future.

Who Must Follow It

The PRC-030-1 mainly applies to the following entities registered with NERC:

1. Transmission Owners (TOs): Responsible for identifying BES disturbances and initiating coordination related to unexpected IBR within their transmission systems.
2. Generator Owners (GOs): Required to provide essential data.  They must provide support for analysis and implement mitigation and/or corrective actions for IBR facilities they own.
3. Generator Operators (GOPs): They are responsible for operating IBR facilities in accordance with corrective actions and providing operational data. They must also coordinate with TOs and GOs during event analysis and mitigation efforts.

Steps to Implement PRC-030-1

For unexpected IBR events, the PRC-030-1 establishes clear guidelines for relevant entities. Below is a sequence aligned for easy understanding:

1. Establishing a Documented Process (R1):

In the first step, it is important to develop and maintain a documented process. This helps to identify any unexpected Inverter-Based Resource behavior following BES disturbances. This will enable entities and personnel to ensure timely coordination with Generator Owners and Operators.

2. Analyze Power Change Events (R2):

The second step is to identify the root cause of the problem. Generator Owners and Operators must analyze the identified behavior related to IBRs. This includes reviewing inverter performance, control/protection settings, and disturbance data.

3. Develop a Corrective Action Plan (R3):

The third step is to create a corrective action strategy. This process can facilitate mitigating the identified issues. This is usually based on the event analysis data. Such a plan outlines specific actions required to prevent the recurrence of future unexpected IBR events.

4. Implement Corrective Actions (R4):

The fourth step is for Generator Owners and Operators to follow the approved corrective actions within the specified timeframe. All relevant documentation must be retained to demonstrate the completion and compliance with PRC-030-1 requirements.