AF1-302 System Impact Study Report

This project is eligible for the Expedited Study process per PJM Tariff Part VII, Subpart B, section 304 and will follow the Expedited Study Process rules outlined in PJM Manual 14H, Attachment I.3.4.

Projects in the Expedited Process will receive a retooled System Impact Study report with the Transition Cycle #1 projects (AE1-AG1) removed from the base case model used for their study. This System Impact Study (SIS) report has been prepared for the AF1-302 project using the updated case model. PJM performed reliability analysis for the project based on the serial study approach using the legacy Generator Deliverability Study method outlined in Manual 14B, Attachment C.3 (Revision 51 of M14B). Summer peak and light load load flow analysis was performed. Short circuit and dynamic stability impacts were also analyzed.

The interconnected Transmission Owner (TO) for this project is Keystone Appalachian Transmission Company. The TO has provided their updated TO analysis results on the lower voltage system based on their own criteria.

This System Impact Study report summarizes both the PJM and TO analysis results for your project.

Note: This updated SIS report does not include any Physical Interconnection Facilities scope or cost estimates from the TO. As this project is in the Expedited Process, a Facilities Study will be conducted by the TO (and any affected Transmission Owner(s)) for updated Physical Interconnection Facilities and System Reinforcement (Network Upgrade) costs. The Facilities Study will be issued to the Project Developers along with the Generator Interconnection Agreement (GIA) as part of the Expedited Process.

The developer has proposed an uprate to a planned/existing Solar generating facility located in the Keystone Appalachian Transmission Company zone — Jefferson County, Pennsylvania. This project is an increase to the developer's AE2-316 project, which will share the same point of interconnection. The AF1-302 project is a 42.0 MW uprate (18.0 MW Capacity uprate) to the previous project. The total installed facilities will have a capability of 132.0 MW with 59.2 MW of this output being recognized by PJM as Capacity.

The AF1-302 project will interconnect with the Keystone Appalachian Transmission Company transmission system as an uprate to AE2-316. The interconnection of the project will be accomplished by connecting to the same POI as the new 138 kV three breaker ring bus substation for AE2-316 on the Brookville - Squab Hollow 138 kV Line. The substation will be located approximately 22.23 miles from Squab Hollow Substation and 6.46 miles from Brookville Substation. The project developer will be responsible for acquiring all easements, properties, and permits that may be required to construct both the new interconnection line tap and the associated interconnection facilities.

Attachment 1 shows a one-line diagram of the proposed primary direct connection facilities for the AF1-302 generation project to connect to the transmission system.

FE performed an analysis of its underlying transmission <100 kV system. The AF1-302 project did not contribute to any overloads on the <100 kV FE transmission system.

PJM Short Circuit Analysis did not identify any new overduty breakers or >3% contribution to previously identified overduty breakers.

Generator Interconnection Request AF1-302 is for a 42 MW uprate of the AE2-316 queue project.

The AF1-302 uprate increased the Maximum Facility Output (MFO) of the plant from 90 MW to 132 MW. AF1-302 has a Point of Interconnection (POI) connecting to the transmission line between Squab Hollow and Brookville 138 kV in Jefferson, Pennsylvania in the First Energy (FE) transmission system.

The power flow scenario for the analysis was based on the RTEP 2023 summer peak case, modified to include applicable queue projects.  AF1-302 has been dispatched online at maximum facility output, with approximately unity power factor at the high side of the station transformer. 

AF1-302 was tested for compliance with NERC, PJM, Transmission Owner and other applicable criteria. For this study, 69 contingencies were simulated, each with a 20 second simulation time period. Studied faults included:

•  Steady-state operation (20 second simulation)

•  Three-phase faults with normal clearing time

•  Single-phase bus faults with normal clearing time

•  Single-phase faults with a stuck breaker with delayed clearing time

•  Single-phase faults placed at 80% of the line with delayed (Zone 2) clearing at remote line end because of primary communications/relaying failure

•  Single-phase faults with loss of multiple circuits caused by a common tower contingency

The 69 fault contingencies tested on the 2023 summer peak case met the recovery criteria:

•  The AF1-302 generators were able to ride through the faults except for faults where protective actions trip one or more generator(s).

•  All generators maintained synchronism and any post-contingency oscillations are positively damped with a damping margin of at least 3%.

•  All bus voltages recover to 0.7 p.u. within 2.5 seconds and the final voltages are within the steady-state voltage ranges below per FE’s transmission planning criteria.

    o       500 kV Facilities: 0.97 to 1.1 p.u.

    o       345, 230, 138, and 115 kV Facilities: 0.92 to 1.05 p.u.

•  No transmission element trips, other than those either directly connected or designated to trip as a consequence of the fault.

No mitigation is required for AF1-302.

The AF1-302 project met the PJM reactive power requirement maintaining 0.95 lagging and 0.95 leading power factor at the high side of the station transformers.

Steady State Voltage analysis is not required for this project at this time.

The Projects below are listed in one or more dispatch for the overloads identified in your report. These projects contribute to the loading of the overloaded facilities identified in your report. The percent overload of a facility and cost allocation you may have towards a particular reinforcement could vary depending on the action of these earlier projects. The status of each project at the time of the analysis is presented in the table. This list may change if any earlier projects withdraw. This table is valid for load flow analyses only.

The AF1-302 project may be responsible for a contribution to the following estimated System Reinforcement (Network Upgrade) costs as shown below. The Network Upgrades listed below are required to alleviate a reliability criteria violation identified in the Network Impact analysis that PJM has performed for this System Impact Study. No physical Interconnection Facilities costs are included in this cost table.

Note 1: PJM Open Access Transmission Tariff (OATT) Part VI, section 217.3A outlines cost allocation rules for the Expedited Process projects. These rules are further clarified in PJM Manual 14A, Attachment B.

Note 2: To Project Developers with System Reinforcements listed: If your present cost allocation to a System Reinforcement indicates $0, then please be aware that if a prior project in the Expedited Process withdraws from the cycle, the cost responsibilities can change and a cost allocation may be assigned to your project. In addition, although the cost allocation to a System Reinforcement is presently $0, your project may need this system reinforcement completed to be deliverable to the PJM system. If your project desires to possibly come into service prior to completion of the system reinforcement, you would need to request an interim deliverability study to determine if all or a portion of your project would be deliverable.

The one line included in this refreshed System Impact Study report was originally developed prior to the Transition Date. Therefore, not all verbiage on the one line may align with the current Tariff definitions. An updated one line diagram will be provided in the Facilities Study report for the Expedited Process projects.

SLD

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