AF1-282 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 AF1-282 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 The Dayton Power and Light 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 a Solar generating facility located in the The Dayton Power and Light Company zone — Highland County, Ohio. The installed facilities will have a total capability of 100.0 MW with 60.0 MW of this output being recognized by PJM as Capacity.

AF1-282 will interconnect on the Dayton transmission system tapping the Stuart to Clinton 345kV line.

No violations.

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

Executive Summary

Generator Interconnection Request AF1-282 is for a 100 MW Maximum Facility Output (MFO) solar generating facility, which consists of 41 x 2.5 MW Chint SCH125KTL-DO/US-600 solar inverters. The solar generating facility will be located in Highland County, Ohio.

This report describes a dynamic simulation analysis of AF1-282 as part of the overall system impact study. Queue project AF1-283 is studied in conjunction with AF1-282 given their proximity to each other. The proposed Point of Interconnection (POI) for both AF1-282 and AF1-283 is Clay 345 kV substation in Dayton.

The load flow scenario for the analysis was based on the RTEP 2023 peak load case, modified to include applicable queue projects. AF1-282 and AF1-283 have been dispatched online at maximum power output, and set to control their terminal voltage to 1.047 pu and 1.043 pu, respectively, to obtain unity power factor at the POI.

AF1-282 was tested for compliance with NERC, PJM, Transmission Owner and other applicable criteria. Steady-state condition and 268 contingencies were studied, each with a 20 second simulation time period. Studied faults included:

       a)       Steady-state operation (20 second);

       b)       Three-phase faults with normal clearing time;

       c)       Single-phase bus faults with normal clearing time;

       d)       Single-phase faults with stuck breaker;

       e)       Single-phase faults placed at 80% of the line with delayed (Zone 2) clearing at line end remote from the fault due to primary communications/relay failure;

       f)       Single phase faults resulting in multiple contingencies;

       g)       Three-phase faults with normal clearing time and a failed high speed reclose attempt.

For all simulations, the queue project under study along with the rest of the PJM system were required to maintain synchronism and with all states returning to an acceptable new condition following the disturbance.

For all of the fault contingencies tested on the 2023 peak load case, the following conclusions were made:

       a)       AF1-282 was able to ride through the faults except for disturbances where protective action trips the generator to clear the fault.

       b)       AF1-282 post-contingency oscillations were positively damped with a damping margin of at least 3%.

       c)       Following fault clearing, all bus voltages recover to 0.7 pu within 2.5 seconds (except where protective action isolates that bus).

       d)       No transmission element tripped, other than those either directly connected or designed to trip as a consequence of that fault.

The system impact study data indicates that AF1-282 would have a +/-33.7 MVAR reactive power capability, which meets both the 0.95 leading and lagging PF requirements at the high side of the main transformer.

The system impact study data indicates that AF1-282 would have a +/-33.7 MVAR reactive power capability, which meets both the 0.95 leading and lagging PF requirements at the high side of the main transformer.

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 AF1-282 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.

Download all tables in report