AF2-027 System Impact Study Report
v1.00 released 2024-10-03 08:48
Zion Energy Center 345 kV
20.0 MW Capacity / 50.0 MW Energy
Introduction
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 AF2-027 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 Commonwealth Edison 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.
General
The developer has proposed a Storage generating facility located in the Commonwealth Edison Company zone — Lake County, Illinois. The installed facilities will have a total capability of 635.0 MW with 20.0 MW of this output being recognized by PJM as Capacity.
| Project Information | |
|---|---|
| New Service Request Number | AF2-027 |
| Project Name | Zion Energy Center 345 kV |
| Developer Name | Zion Energy LLC |
| State | Illinois |
| County | Lake |
| Transmission Owner | Commonwealth Edison Company |
| MFO | 635.0 MW |
| MWE | 50.0 MW |
| MWC | 20.0 MW |
| Fuel Type | Storage |
| Basecase Study Year | 2023 |
Point of Interconnection
AF2-027 will interconnect on the ComEd transmission system as an uprate to Y3-013 at the Zion Energy Center 345 kV substation.
Transmission Owner Analysis
None.
Summer Peak Analysis
The Project was evaluated as a 50.0 MW (Capacity 20.0 MW) injection in the ComEd area. Project was evaluated for compliance with applicable reliability planning criteria (PJM, NERC, NERC Regional Reliability Councils, and Transmission Owners). Potential Summer peak period network impacts were as follows:
(No impacts were found for this analysis)
Summer Potential Congestion due to Local Energy Deliverability
PJM also studied the delivery of the energy portion of this interconnection request. Any problems identified below are likely to result in operational restrictions to the project under study. The developer can proceed with network upgrades to eliminate the operational restriction at their discretion by submitting an Upgrade Request.
Note: Only the most severely overloaded conditions are listed below. There is no guarantee of full delivery of energy for this project by fixing only the conditions listed in this section.
(No impacts were found for this analysis)
Light Load Analysis
The Project was evaluated as a 50.0 MW (Capacity 20.0 MW) injection in the ComEd area. Project was evaluated for compliance with applicable reliability planning criteria (PJM, NERC, NERC Regional Reliability Councils, and Transmission Owners). Potential light load period network impacts were as follows:
(No impacts were found for this analysis)
Light Load Potential Congestion due to Local Energy Deliverability
(No impacts were found for this analysis)
Short Circuit Analysis
PJM Short Circuit Analysis did not identify any new overduty breakers or >3% contribution to previously identified overduty breakers.
Stability Analysis
Generator Interconnection Request AF2-027 is for a 50 MW uprate of the existing natural gas facility, Y3-013. The uprate increases the Maximum Facility Output (MFO) of the facility from 585 MW to 635 MW. AF2-027 consists of 21 x 2.4621 MW GE-RIU-2750 battery storage inverters with a Point of Interconnection (POI) at the existing Zion Energy Center 345 kV substation, in the Commonwealth Edison Interconnected System (ComEd) transmission system, Lake County, Illinois.
A dynamic simulation analysis of AF2-027 was conducted as part of the overall system impact study.
The load flow scenario for the analysis was based on the RTEP 2023 peak load case, modified to include applicable queue projects. AF2-027 has been dispatched online at maximum power output, with 1.0 p.u. voltage at the generator bus.
AF2-027 was tested for compliance with NERC, PJM, Transmission Owner and other applicable criteria. Steady-state condition and 68 contingencies were studied, each with a 20 second simulation time period. Studied faults included:
a) Steady-state operation (20 second run);
b) Three-phase faults with normal clearing time;
c) Three-phase faults with three-phase delayed clearing due to a stuck breaker (GO breakers with FD Logic);
d) Three-phase Faults with Loss of Multiple-Circuit Tower Line.
No relevant high-speed reclosing (HSR) contingencies nor single-phase bus faults were identified for this study.
There are no delayed (Zone 2) clearing faults due to dual primary relays being employed in the ComEd 345 kV Transmission System.
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:
a) AF2-027 was able to ride through the faults (except for faults where protective action trips a generator(s)),
b) The system with AF2-027 included is transiently stable and post-contingency oscillations were positively damped with a damping margin of at least 3% for interarea modes and 4% for local modes.
c) Following fault clearing, all bus voltages recovered to a minimum of 0.7 per unit after 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 reactive power capability of AF2-027 meets the 0.95 lagging and leading PF requirement at the high side of the main transformer.
The composite short-circuit ratio (CSCR) assessment was performed for inverter-based renewable generation units which are within one (1) substation away of AF2-027. The CSCR results are summarized in Table 7 through Table 10 and revealed a minimum and maximum CSCR values of 3.2976 for P7.10 and 13.1707 for P0.01, respectively.
AF2-027 exhibited slow reactive power recovery for several contingencies. This issue did not cause instability in the system and the model was tuned to have faster reactive power output settlement by adjusting the VCFlag and Kc parameters in the plant controller (REPCAU1) for AF2-027 as follows :
• VCFlag = 0 (originally set to 1)
• Kc = 0.06 (originally set to 0.02).
Multiple instances of network non-convergence were reported at AF2-027 generator bus during a three-phase fault at AF2-027 POI. Also, non-convergence was observed at AF2-027 generator bus several cycles after fault clearing time. However, AF2-027 generator performed normally in the contingencies. No further investigation is needed .
No mitigations were found to be required.
Reactive Power Analysis
This project meets the power factor requirements.
Steady-State Voltage Analysis
Steady State Voltage analysis is not required for this project at this time.
New Service Request Dependencies
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.
| New Service Requests Dependencies | ||
|---|---|---|
| Project | Project Name | Status |
Affected Systems
System Reinforcements
The AF2-027 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.
Attachments
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.