SYSTEM IMPACT STUDY REPORT LA450S … report was prepared for the project Interconnection Customer, by ... Table 2-3: Stability Contingencies ... 345/115 kV Transformer (400 MVA)

SYSTEM IMPACT STUDY

REPORT

LA450S GENERATION STUDY

Prepared for:

El Paso Electric Company

Prepared by:

TRC Engineers, LLC 1526 Cole Boulevard

Building 3, Suite 150

Lakewood, CO 80401

(303) 395-4018

June 2017

LA450S System Impact Study TRC June 2017 i

FOREWORD

This report was prepared for the project Interconnection Customer, by System Planning at El Paso

Electric Company. Any correspondence concerning this document, including technical and commercial

questions should be referred to:

David Tovar

Manager – System Planning Department


100 North Stanton, Loc. 751

El Paso, Texas 79901

Phone: (915) 543-4355

Fax: (915) 521-4763

or

Roberto Favela

Principal Engineer


100 North Stanton, Loc. 751

El Paso, Texas 79901

Phone: (915) 521-4418

Fax: (915) 521-4763

LA450S System Impact Study TRC June 2017 ii

Table of Contents

EXECUTIVE SUMMARY ........................................................................................................................................... 4

1.0 INTRODUCTION ........................................................................................................................................... 9

2.0 STUDY METHODOLOGY ......................................................................................................................... 11 2.1 ASSUMPTIONS & CRITERIA ............................................................................................................................ 11 2.2 PROCEDURE ................................................................................................................................................... 12

Development and Description of Cases ............................................................................................... 12 2.2.1

LA450S Study Generation Modeling.................................................................................................... 13 2.2.2

NRIS Project Dispatch and Analysis Description ................................................................................ 13 2.2.3

ERIS Project Dispatch and Analysis Description ................................................................................ 14 2.2.4

Contingency Lists ................................................................................................................................. 14 2.2.5

3.0 STEADY STATE POWER FLOW ANALYSIS .......................................................................................... 16 3.1 NORMAL OPERATING CONDITION POWER FLOW EVALUATION ...................................................................... 16

Pre-project N-0 Power Flow Evaluation ............................................................................................. 16 3.1.1

Post-project N-0 Power Flow Evaluation ............................................................................................ 16 3.1.2

3.2 EMERGENCY OPERATING CONDITION POWER FLOW EVALUATION ................................................................ 16 Pre-project N-1 Power Flow Evaluation ............................................................................................. 16 3.2.1

NRIS Post-project N-1 Power Flow Evaluation .................................................................................. 16 3.2.2

ERIS Post-project N-1 Power Flow Evaluation................................................................................... 17 3.2.3

3.3 NRIS NETWORK UPGRADE POWER FLOW TESTING ....................................................................................... 18 3.4 ERIS EVALUATION ........................................................................................................................................ 20 3.5 EXTREME OUTAGE PROTECTION .................................................................................................................... 21 3.6 POWER FLOW ANALYSIS CONCLUSION .......................................................................................................... 21

4.0 STEADY STATE VOLTAGE ANALYSIS ................................................................................................. 22 4.1 NORMAL OPERATING CONDITION VOLTAGE EVALUATION ............................................................................ 22 4.2 EMERGENCY OPERATING CONDITION VOLTAGE EVALUATION ...................................................................... 22 4.3 DELTA VOLTAGE EVALUATION ..................................................................................................................... 22 4.4 POWER FACTOR TEST .................................................................................................................................... 22 4.5 STEADY STATE VOLTAGE ANALYSIS CONCLUSIONS ...................................................................................... 23

5.0 SHORT CIRCUIT ANALYSIS .................................................................................................................... 24 5.1 SHORT CIRCUIT ANALYSIS MODELING .......................................................................................................... 24 5.2 SHORT CIRCUIT ANALYSIS PROCEDURE ......................................................................................................... 24 5.3 SHORT CIRCUIT ANALYSIS RESULTS AND CONCLUSION ................................................................................ 25

6.0 STABILITY ANALYSIS ............................................................................................................................. 29 6.1 DYNAMIC MODELING .................................................................................................................................... 29 6.2 STABILITY STUDY CASE DEVELOPMENT ........................................................................................................ 29 6.3 PRELIMINARY NRIS STABILITY ANALYSIS .................................................................................................... 29 6.4 FINAL NRIS STABILITY ANALYSIS RESULTS ................................................................................................. 30 6.5 FINAL ERIS STABILITY ANALYSIS RESULTS .................................................................................................. 31 6.6 LOW VOLTAGE RIDE THROUGH TEST ............................................................................................................ 31 6.7 SYSTEM INERTIA ANALYSIS ........................................................................................................................... 31 6.8 STABILITY ANALYSIS CONCLUSION ............................................................................................................... 32

7.0 COST ESTIMATES, ONE-LINES, & PROJECT SCHEDULE .................................................................. 33

8.0 DISCLAIMER .............................................................................................................................................. 41

9.0 CONCLUSIONS ........................................................................................................................................... 42

LA450S System Impact Study TRC June 2017 iii

List of Tables

Table 0-1: NRIS Project Cost Estimate ....................................................................................................... 7 Table 2-1: EPE and New Mexico Performance Criteria ............................................................................ 12 Table 2-2: Pre-Project Base Case Scenarios .............................................................................................. 13 Table 2-3: Stability Contingencies ............................................................................................................. 14 Table 3-1: LA450S Impacts to Summer Emergency Equipment Loading – NRIS ................................... 16 Table 3-2: LA450S Impacts to Winter Emergency Equipment Loading – NRIS ...................................... 17 Table 3-3: LA450S Impacts to Summer Emergency Equipment Loading – ERIS .................................... 17 Table 3-4: LA450S Impacts to Winter Emergency Equipment Loading – ERIS ...................................... 18 Table 5-1: Generator Short Circuit Modeling Data ................................................................................... 24 Table 5-2: Short Circuit Analysis Results (Area 10) ................................................................................. 25 Table 5-3: Short Circuit Analysis Results (Area 11) ................................................................................. 26 Table 6-1: Transient Stability Analysis Preliminary Results ..................................................................... 29 Table 6-2: Transient Stability Analysis Post-Network Upgrade Results ................................................... 31 Table 7-1: Cost Estimate ............................................................................................................................ 33 Table 7-2: EPE Interconnection Facilities Costs for POI Station (LA450S) ............................................. 37 Table 7-3: EPE Network Upgrade Costs for the LA450S POI Station ...................................................... 37

List of Figures

Figure 1-1: Year 2019 EPE Transmission System with LA450S POI .......................................................... 9

Figure 3-1: Year 2019 EPE Transmission System with LA450S POI and Network Upgrades .................. 20 Figure 7-1: LA450S POI Station One Line ................................................................................................ 36 Figure 7-2: Afton North Switching Station One Line (Network Upgrade) ................................................ 38 Figure 7-3: Anthony Substation One-line ................................................................................................... 39

Appendices

Appendix A LA450S Project Modeling Information Appendix B Power Flow Contingency List

Appendix C Pre-Project Stability Plots

Appendix D Preliminary Stability Plots

Appendix E Final Stability Plots

Appendix F Stability Run Summary Reports

Appendix G LA450S Project Schedule

Appendix H System Inertia Analysis Plots

LA450S System Impact Study TRC June 2017 4

LA450S Generation System Impact Study

EXECUTIVE SUMMARY

The objective of this System Impact Study (SIS) was to determine the impact of the proposed LA450S

Project (Project) on the El Paso Electric Company (EPE) transmission system. In addition, EPE

identified Public Service of New Mexico (PNM) and Tri-State Generation and Transmission (TSGT) as

Affected Systems, given the location of the proposed interconnection. The proposed LA450S Project

(Project) is comprised of 450 MW of Photovoltaic (PV) solar powered generation to be interconnected on

an existing 345 kV line running between EPE’s Luna and Afton North Substations.

The proposed Commercial Operation date for the Project is January 31, 2019.

In planning year 2019, EPE plans to complete a system reinforcement around the Afton Substation. The

planned reinforcement includes the creation of the Afton North Substation, tapping the Luna-Diablo 345

kV line at Afton, and creating a 115 kV path between Afton and Airport. For the purpose of this SIS, the

system reinforcements around Afton, including the creation of the Afton North Substation, were all

considered complete and modeled as in-service.

In this SIS, the Project was evaluated for Network Resource Interconnection Service (NRIS) and for

Energy Resource Interconnection Service (ERIS), as defined in the EPE Open Access Transmission Tariff

(OATT).

When tested for NRIS, the entire 450 MW Project output was delivered to serve EPE native load.

The NRIS study assumed that the output of the Generating Facility may displace the output of other

Network Resources on the EPE Transmission System, and then identifies the Network Upgrades that

would be required to allow the Generating Facility to be counted towards system resource needs in the

same manner as the displaced EPE resources. To be clear, the identification of Network Resources set

forth herein does not eliminate the need for studies to be performed if and when an application is

submitted to request transmission service for the delivery of the output of the Generating Facility, whether

the transmission service requested is Network Integration Transmission Service or Firm Point-to-Point

Transmission Service. After receipt of a transmission service request, the Transmission Provider may

perform studies and those studies may identify additional upgrades necessary to allow delivery service

under the OATT.

In contrast, the identification of Network Upgrades in the generator interconnection study is for the

purpose of allowing the Interconnection Customer to be eligible to have its resource designated as a

Network Resource on the EPE system. The upgrades identified in the report would be necessary for EPE

to integrate the Generating Facility into the EPE Transmission System in a manner that permits aggregate

generation to meet aggregate EPE load while satisfying reliability criteria and planning requirements, and

without impinging upon adjacent transmission systems.

When tested as an ERIS, 100 MW of Project generation was delivered to serve EPE native load. The

remaining 350 MW of Project generation was sent to Western Electric Coordinating Council (WECC)

loads in Western and Northern New Mexico (as per the LA450S Interconnection Request).

This System Impact Study Report addresses generation interconnection upgrades only, and does not

address or imply any right to receive transmission service from EPE or any other transmission provider.


The Study Areas for both the NRIS and ERIS analysis were limited to WECC Areas 11 - EPE and 10 –

PNM and TSGT.

Senior queued projects in the EPE study queue that were included in all base cases for this SIS. The 420

MW Montana Power Station (MPS) Project, the 90 MW Santa Teresa Solar (DS90S) Project, and the 200

MW Otero Solar (CA200S) Project. All three projects were added to the study models.

For both the NRIS and ERIS tests, Steady State and Stability analysis was conducted using two

benchmark cases provided by EPE. The cases were a 2019 Heavy Summer (Peak) and a 2018/2019 Light

Winter (Off Peak). A sensitivity case was also developed to determine Project impacts on dispatch

scenarios with the MPS Project being online or offline.

Afton generation was assumed online in all Peak cases and offline in the Off Peak cases. The Arroyo

Phase Shifter was set to regulate N-S Flows from in all cases (10-20 MW under Peak loads and 150-160

MW under Off Peak loads). The Eddy County HVDC was set to import 200 MW in all Peak cases and

was off-line in the Off Peak case.

Steady State Results

For NRIS, the LA450S Project must include the following set of Network Upgrades:

1. Upgrade Anthony Substation by creating a 345 kV bus and adding a

345/115 kV Transformer (400 MVA).

2. Upgrade Afton North Substation to include an additional 345 kV line

3. Build Afton North-Anthony 345 kV Line (17.4 miles)

After the addition of the proposed Network Upgrades, Power Flow Analysis Results showed there are no

remaining overloaded facilities, under applicable N-0 or N-1 conditions, caused or worsened by the

addition of the LA450S Project. Please note however that potential curtailment of LA450S under certain

N-2 conditions will be investigated further within the Facilities Study Report.

For ERIS, the LA450S Project can reach a maximum capacity of 250 MW on an as-available basis before

causing a criteria violation.

Short Circuit Results

A Short Circuit analysis was performed to determine if the addition of the LA450S generation would

cause any existing EPE or PNM and TSGT transmission system circuit breakers to exceed their

interrupting ratings.

The results of the short circuit analysis show that after the addition of the Project maximum fault currents

did not exceed breaker interrupting capability at any EPE or PNM circuit breakers.

Stability Results

The LA450S dynamic model was provided by the developer as TMEIC manufactured 2.7 MVA, 600 V

inverter which consists of the WECC required regc_a, reec_b, and repc_a models with appropriate

voltage and frequency parameters for to comply with Low Voltage Ride Through criteria.

Transient system stability was analyzed for faults relevant to the LA450S Study Areas under both Peak

and Off Peak load conditions. The analysis compared the system response to the fault simulations before

and after the LA450S generation was added at its maximum requested 450 MW capacity in both the


NRIS and ERIS evaluation. Additional testing was also completed after the addition of the Network

Upgrades in the NRIS evaluation, and with the Project at 250 MW capacity in the ERIS evaluation.

Results from the stability analysis showed that the EPE and Southwestern New Mexico transmission

system remained stable for all simulated faults. A Low Voltage Ride Through (LVRT) test was also

completed. LVRT testing showed the Project can withstand a 9 cycle fault at the POI.

Cost Estimates and Schedule

Good faith cost estimates are presented. The cost estimates are in 2017 dollars (no escalation applied)

and are based upon typical construction costs for previously performed similar construction. These costs

include all estimated applicable labor and overheads associated with the engineering, design, and

construction of these new EPE facilities. These estimates did not include the Generator Interconnection

Costs1 for any other Interconnection Customer owned equipment or associated design and engineering

except for the POI facilities.

The estimated total cost for the required upgrades is $58.94 Million for LA450S project. This breaks

down to $0.77 Million for the EPE Interconnection Costs2 at the POI, $9.00 Million for the LA450S POI

Costs, and $49.17 Million for Network Upgrade Costs3. Error! Reference source not found. details the

estimated costs. Please note that Network Upgrade costs only apply to a NRIS evaluation. However the

EPE Interconnection costs, and the LA450S POI Substation costs apply to both the NRIS and ERIS

evaluations.

Please note, associated Generator Interconnection Costs have not been estimated as part of this study.

The estimated time frame for Engineering, Procurement, and Construction for NRIS is approximately 45

months upon notice to proceed with construction from the Interconnection Customer. The estimated time

frame for Engineering, Procurement, and Construction for ERIS is approximately 39 months, and subject

to equipment availability lead-times, upon notice to proceed with construction from the Interconnection

Customer.

The time estimates presented in this study assume that there is no suspension of work directed by the

Interconnection Customer under its Interconnection Agreement.

1 Generator Interconnection Costs: cost of facilities paid for by Interconnection Customer and owned and

2 EPE Interconnection Costs: cost of facilities paid for by Interconnection Customer but owned and operated by

EPE from the Change of Ownership Point to the Point of Interconnection.

3 Network Upgrades Costs: cost of facilities from the Point of Interconnection outward, paid for by the

interconnector but owned and operated by EPE.


Table 0-1: NRIS Project Cost Estimate

Project Item

EPE

Interconnection

Cost

(in millions)

Substation

Network

Upgrade

Cost

(in millions)

Transmission

Network

Upgrade

Cost

(in millions)

Total

Cost

(in millions)

LA450S

LA450S

Interconnection

Switching Station

$0.77 $ 9.00 $ 9.77

Anthony

Substation

Upgrades*

$ 9.88 $ 9.88

North Afton

Substation

Upgrades*

$ 4.81 $ 4.81

345 kV Line

Between Afton and

Anthony*

$ 34.48 $ 34.48

Total Cost LA450S NRIS $ 58.94 M

Total Cost LA450S ERIS $ 9.77 M

*Denotes NRIS Cost Only

Conclusion

The results of the NRIS evaluation showed the need for a new, 17.4 mile long, 345 kV transmission line

between Afton and Anthony Substation. In addition to this new 345 kV line a 345/115 kV transformer,

and new 345 kV switchyard is also needed at Anthony.

The required Network Upgrades for LA450S interconnection are as follows:


345/115 kV Transformer.


3. Build Afton North-Anthony 345 kV Line (17.4miles)

These reinforcements are required if LA450S is used to serve native EPE load and offset local EPE

conventional generation. Results showed no remaining criteria violations after the addition of these

Network Upgrades.

The results of the ERIS evaluation showed that LA450S can operate on an as-available basis at a

maximum capacity of 250 MW before creating a criteria violation. (During ERIS evaluation LA450S

generation was delivered to EPE native load versus WECC loads in New Mexico/Arizona at the requested

1 to 3.5 ratio.)

The estimated cost for integrating the LA450S Project onto the EPE transmission system as an ERIS

Project is $9.77 Million. The good faith estimate for the time frame to Engineer, Procure, and Construct

the POI facilities for an ERIS Project is 39 months, (upon notice to proceed from tine Interconnection

Customer).

The estimated cost for integrating the LA450S Project onto the EPE transmission system as an NRIS

Project is $58.94 Million, including the cost for associated Network Upgrades. The good faith estimate


for the time frame to Engineer, Procure, and Construct all facilities at the POI and the associated Network

Upgrade Substations is 45 months, (upon notice to proceed from tine Interconnection Customer).


1.0 INTRODUCTION

The Federal Energy Regulatory Commission (FERC) requires that a SIS be performed for generation

facilities desiring to connect to any Transmission System. Here, the Interconnection Customer seeks to

interconnect to the EPE Transmission System and to have its generating facility studied for Network

Resource Interconnection Service (NRIS), and also for Energy Resource Interconnection Service (ERIS).

The proposed LA450S Project is comprised of 450 MW of PV solar powered generation requesting to be

interconnected on an existing 345 kV line running between the Luna and Afton North Substations. The

proposed Commercial Operation date for the Project is January 31, 2019.

In planning year 2019, EPE plans to complete a system reinforcement around the Afton Substation. The

planned reinforcement includes the creation of the Afton North Substation, tapping the Luna-Diablo 345

kV line at Afton, and creating a 115 kV path between Afton and Airport. For the purpose of this SIS, the

system reinforcements around Afton, including the creation of the Afton North Substation, were all

considered complete and modeled as in-service in all SIS cases.

Figure 1-1 shows the LA450S project included in the 2019 transmission planning map.

Figure 1-1: Year 2019 EPE Transmission System with LA450S POI

In this SIS, two separate analysis were performed to test the Project as either a Network or Energy

Resource, as defined in the EPE OATT. When tested as a Network Resource, generation from the full

Project output was delivered to serve EPE native load.


When tested as an Energy Resource, 100 MW of Project generation was delivered to serve EPE native

load. The remaining 350 MW of Project generation was sent to WECC loads in Western and Northern

New Mexico (as per the LA450S Interconnection Request).

The Study Areas for the analysis were limited to WECC Areas 11 - EPE and 10 - PNM.

The Study was performed in accordance with Western Electricity Coordinating Council (WECC), North

American Electric Reliability Corporation (NERC), and EPE standards. The EPE local reliability

standards can be found in Section 4 of EPE’s FERC Form No. 715. The steady state and stability analysis

was performed using General Electric’s (GE) Power System Load Flow (PSLF) software Version 19.


2.0 STUDY METHODOLOGY

2.1 Assumptions & Criteria

The following assumptions are consistent for all study scenarios unless otherwise noted.

This study assumed that all system expansion projects as planned by area utilities by the year

under analysis are completed, and that any system improvements required by the interconnections

senior to the LA450S Study generation are implemented.

This study did not analyze any transmission service from the interconnection point to any specific

point on the grid for the interconnections senior to the LA450S Study generation.

For NRIS, the Project generation was dispatched and delivered to serve EPE native load. To the

extent the Interconnection Customer were to seek to transmit the Project generation to a particular

delivery point on the EPE Transmission System, additional studies would have to be conducted as

part of a point-to-point transmission service request.

For ERIS, the Project generation was dispatched and delivered to EPE native load and WECC

loads at a 1 to 3.5 ratio.

Transformer tap and phase-shifting transformer angle movement, as well as static var device

switching, were allowed for the steady state pre-contingency analysis. All regulating equipment

such as transformer controls and switched shunts were fixed at pre-contingency positions when

the contingency analysis was performed. For post-contingency analysis Static var device

switching was allowed, but all other regulation equipment was locked.

All facility loadings at voltages 69 kV and greater were monitored within the El Paso and PNM

control areas. Pre-contingency and Post-contingency flows on lines and transformers were

required to remain at or below the normal rating, while post-contingency flows on lines and

transformers were required to remain at or below the emergency rating. Flows above 100% of an

element’s pre-project or post-contingency rating were considered violations. All post-project

voltage criteria violations that improve an existing pre-project violation were not considered an

adverse impact to the system.

The performance criteria utilized for qualifying violations in the study area are shown in

.


Table 2-1: EPE and New Mexico Performance Criteria

2.2 Procedure

To test the Project for NRIS, Steady State and Transient Stability Analysis was completed. A separate,

Steady State and Transient Stability Analysis was completed to test the Project for ERIS. A Short Circuit

Duty Analysis and Steady State Power Factor Test was also completed to determine the Project impacts

to the EPE system. Presented below is a description of the procedures used to complete the analyses.

Development and Description of Cases 2.2.1

Two benchmark cases 2019 Heavy Summer (Peak) and 2018/2019 Light Winter (Off Peak) were

provided by EPE to develop the Pre-project study cases. The same Pre-project study cases were used for

the Energy and Network Resource analysis.

Both study cases were developed with the senior queued projects DS90S and CA200S as being in service.

The DS90S project is proposed to be 90 MW interconnected between the proposed NW2 and Santa

Teresa 115 kV Substations. The CA200S project is proposed to be 200 MW interconnected between the

proposed Picante and Amrad 345 kV Substations. (Note: The addition of CA200S includes an associated

Network Upgrade to create a new 345 kV Substation between CA200S and Picante. After the Upgrade

the CA200S project will interconnect between Amrad and the new Corona 345 kV Substations.)

As shown in Table 2-2, the Eddy County HVDC is online in both Peak case scenarios (with and without

MPS) and Eddy County HVDC is offline in the Off Peak scenario. Afton Generation was modeled in

service for Peak cases and out of service for Off Peak cases. The Arroyo Phase Shifter was modeled to

provide 10-20 MW N-S flow under Peak load conditions and 150-160 MW N-S flow during the Off Peak

load conditions.

In total there are (3) pre-project study cases. MPS Generation was modeled offline for all Off Peak cases.

For the Peak load scenario, sensitivity cases were created with MPS switched on and off. The MPS


project consists of four (4) 88 MW (summer rated) and 105 MW (winter rated) gas powered units that are

now in-service and located about 3 miles east of EPE’s Caliente Substation. Generation for all senior

queued projects, including MPS, DS90S, and CA200S were modeled as delivered to EPE native load.

The Off Peak case was modified to include minimum EPE gas-fired generation online and maximum

renewable generation online. In order to serve EPE load with maximum renewable generation in the Off

Peak case, EPE imports were set to 633 MW. (EPE imports in the Peak case remain at 747 MW, as in the

provided case.)

Table 2-2: Pre-Project Base Case Scenarios

LA450S Study Generation Modeling 2.2.2

The generation facility will be located about 52 miles northwest of the Afton North 345 kV substation and

5.3 miles southeast of the Luna 345 kV substation. The requested maximum full output of this project is

450 MW at the POI.

The LA450S generation will consist of over 170 inverters rated at 2.7 MVA each. The proposed inverters

are manufactured by TMEIC. The PVH-L2700GR inverters are to be installed at a terminal voltage of

0.6 kV. This initial voltage would be immediately stepped up to the 34.5 kV collector voltage that is

planned for the PV installations. A 345/34.5 kV main transformer will then step up the collector voltage

to the 345 kV EPE Transmission System voltage.

Included as Appendix A is a general one-line of the full LA450S installation. Also in Appendix A is

modeling documentation for the TMEIC inverters.

Post-project study cases were created by adding the LA450S Project to the cases listed in Error!

Reference source not found.. The Project was model in the cases as a lumped equivalent 450 MW

generator, with a single lumped equivalent 345/34.5 kV main POI transformer.

NRIS Project Dispatch and Analysis Description 2.2.3

For the Network Resource Analysis, the entire 450 MW of Project generation was dispatched to serve

EPE system native load. In the MPS-Off Peak cases, Project generation was offset by reducing output at

online gas EPE gas units. In the MPS-On Peak cases, Project generation was offset by reducing output at

online gas EPE gas units, which included MPS reduction to 160 MW output.

In the Off Peak case, EPE gas generation was dispatched at roughly 340 MW in the Pre-project scenario.

EPE requires that at least one gas unit remain online. Therefore, to dispatch the 450 MW of Project

generation to serve native EPE load in the Off Peak case. The follow steps were completed:

1. Reduce online EPE gas generation to 50 MW output at MPS #1.


2. Keep EPE import fixed at 633 MW.

3. Uniformly increase EPE load from 1325 MW to 1495 MW.

Please note, if LA450S is pursued as a Network Resource, EPE imports may need to be reduced once

EPE load reaches a low limit of 1495 MW, under heavy renewable dispatch scenarios.

The Network Resource Analysis consisted of Steady State and Transient Stability Analysis. The set of

contingencies described in Section 2.2.5 were tested. Network Upgrade solutions were developed to

address criteria violations caused by the Project.

ERIS Project Dispatch and Analysis Description 2.2.4

For the Energy Resource Analysis, the LA450S Project was initially dispatched to serve 100 MW of EPE

system load and 350 MW of WECC loads in Western and Northern New Mexico. The set of

contingencies described in Section 2.2.5 were tested on the initial set of Energy Resource cases (Peak and

Off Peak).

During the Energy Resource Analysis, Project generation was reduced until all criteria violations were

removed. As Project generation was reduced, the dispatch was proportionately changed so that the

Project served EPE system load and WECC loads consistent with the 100 MW to 350 MW initial Energy

Resource dispatch.

Contingency Lists 2.2.5

The steady state contingency list can be found in Appendix B. The stability contingency lists is shown

below in Table 2-3. Both lists were selected based on engineering judgement to represent a good cross

section of potential contingencies that would stress the EPE and PNM systems.

Table 2-3: Stability Contingencies

Fault Type Location Duration Trip

3-Phase Afton North 345 kV 5 cycles Afton North - Newman 345 kV

3-Phase* Afton North 345 kV 5 cycles Afton North - Luna 345 kV

3-Phase** Afton North 345 kV 5 cycles Afton North - LA450S 345 kV

3-Phase Afton 345 kV 5 cycles Afton - Diablo 345 KV

3-Phase Afton 345 kV 5 cycles Loss of all Afton Gen

3-Phase* Luna 345 kV 5 cycles Luna – Afton North 345 kV

3-Phase** Luna 345 kV 5 cycles Luna – LA450S 345 kV

3-Phase Diablo 345 kV 5 cycles Afton - Diablo 345 KV

3-Phase Hidalgo 345 kV 5 cycles Luna - Hidalgo 345 KV

3-Phase LEF 345 kV 5 cycles Luna - LEF 345 KV and LEF Gen

3-Phase Luna 345 kV 5 cycles Luna - Afton North 345 KV

3-Phase Luna 345 kV 5 cycles Luna - Macho Springs 345 KV

3-Phase Luna 345 kV 5 cycles Luna - Hidalgo 345 KV

3-Phase Luna 345 kV 5 cycles Luna - LEF 345 KV and LEF Gen

3-Phase Luna 345 kV 5 cycles Luna 345/115 kV XMFR

3-Phase Luna 115 kV 5 cycles Luna 345/115 kV XMFR

3-Phase Macho Springs 345 kV 5 cycles Macho Springs - Springville 345 kV


Fault Type Location Duration Trip

3-Phase Macho Springs 345 kV 5 cycles Macho Springs - Luna 345 kV

3-Phase Newman 345 kV 5 cycles Newman – Afton North 345 kV

3-Phase Newman 345 kV 5 cycles Newman - Arroyo 345 kV

3-Phase Newman 345 kV 5 cycles Newman - Corona 345 kV

3-Phase Newman 345 kV 5 cycles Newman 345/115 kV XMFR #1

3-Phase Springville 345 kV 5 cycles Macho Springs - Springville 345 kV

3-Phase** LA450S POI 345 kV 5 cycles LA450S – Amrad 345 kV

3-Phase** LA450S POI 345 kV 5 cycles LA450S – Picante 345 KV

3-Phase** LA450S POI 345 kV 5 cycles LA450S 345/34.5 kV XFMR

3-Phase** LA450S POI 345 kV 9 cycles LVRT

N/A

No Fault** N/A N/A LA450S Generation

* Pre-project Only ** Post-project Only


3.0 STEADY STATE POWER FLOW ANALYSIS

This section provides a high-level understanding of the LA450S impact on the loading of transmission

lines and transformers in the Study Area. The analysis was performed under both normal and

contingency conditions. Peak and Off Peak base cases were evaluated for thermally overloaded facilities

under both normal (N-0) and contingency (N-1) conditions prior to the addition of the LA200S

generation.

3.1 Normal Operating Condition Power Flow Evaluation

Power flow analysis was completed under system Normal (N-0) conditions before and after the addition

of the Project using both the Peak and Off Peak cases.

Pre-project N-0 Power Flow Evaluation 3.1.1

Power flow analysis results showed no overloaded transmission facilities were present in the El Paso

Electric (EPE) and Public Service Company of New Mexico (PNM) areas under Normal (N-0) system

conditions prior to the addition of LA450S generation.

Post-project N-0 Power Flow Evaluation 3.1.2

After the addition of LA450S, power flow study results continued to show no overloaded transmission

facilities in the El Paso Electric (EPE) and Public Service Company of New Mexico (PNM) areas under

Normal system conditions in both the Network Resource and Energy Resource Analysis.

3.2 Emergency Operating Condition Power Flow Evaluation

Contingency power flow analysis was completed by testing the contingencies listed in Appendix B on the

Peak and Off Peak cases both before and after the addition of the Project.

Pre-project N-1 Power Flow Evaluation 3.2.1

Power flow analysis results showed no overloaded transmission facilities were present in the El Paso

Electric (EPE) and Public Service Company of New Mexico (PNM) areas under Emergency (N-1) system

conditions prior to the addition of LA450S generation.

NRIS Post-project N-1 Power Flow Evaluation 3.2.2

Dispatching LA450S for NRIS has potential to create overloads on the Western and Central portions of

the EPE transmission. The results presented in Table 3-1 and in Table 3-2 show the criteria violations for

the Peak and Off Peak scenarios when the Project was tested as an NRIS.

Table 3-1: LA450S Impacts to Summer Emergency Equipment Loading – NRIS

Monitored Element & Contingency Results (% of Rating)

Pre-LA450S Post- LA450S

From

Bus Name kV

To

Bus Name kV

MVA

Rate Contingency Description 2019HS

2019HS

_MPS 2019HS

2019HS

_MPS

JORNADA 115 ARROYO 115 73.9 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 86% 86% 166% 163%

NEWMAN 345 NEWMAN 115 265 Line NEWMAN 345.0 to

CORONA 345 Circuit 1 50% 62% 121% 121%




From

Bus Name kV

To

Bus Name kV

MVA


2019HS

_MPS 2019HS

2019HS

_MPS

NEWMAN 345 NEWMAN 115 265 Line AFTON 345.0 to

DIABLO 345.0 Circuit 1 65% 97% 127% 139%

NEWMAN 345 AFTON_N 345 1028 Line AFTON 345.0 to

DIABLO 345.0 Circuit 1 70% 71% 107% 108%

MESA___# 115 AUSTIN_N 115 207.4 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 78% 83% 125% 121%

SUNSET_N 115 DURAZNO 115 169.3 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 88% 85% 130% 123%

DIABLO 115 DIABLO 345 258 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 79% 80% 117% 118%

DONA_ANA 115 PICACHO 115 108 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 59% 60% 116% 115%


AFTON_N 345.0 Circuit 1 79% 79% 116% 116%


AFTON_N 345.0 Circuit 1 78% 78% 114% 115%

LUNA 345 LUNA 115 224 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 92% 92% 113% 113%

Table 3-2: LA450S Impacts to Winter Emergency Equipment Loading – NRIS


2019LW

From

Bus Name kV

To

Bus Name kV

MVA

Rate Contingency Description

Pre-

LA450S

Post-

LA450S

NEWMAN 345 NEWMAN 115 265 Line NEWMAN 345.0 to

CORONA 345 Circuit 1 67.7% 127.9%

NEWMAN 345 NEWMAN 115 265 Line AFTON 345.0 to

DIABLO 345.0 Circuit 1 57.7% 116.2%


AFTON_N 345.0 Circuit 1 87.2% 110.9%

SUNSET_N 115 DURAZNO 115 169.3 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 74.2% 110.0%

DONA_ANA 115 PICACHO 115 108 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 47.3% 109.0%


AFTON_N 345.0 Circuit 1 56.9% 103.4%

ERIS Post-project N-1 Power Flow Evaluation 3.2.3

Dispatching the full 450 MW of LA450S for ERIS shows a different set of initial overloads. The results

presented in Table 3-3 and in

Table 3-4 show the worst monitored/contingency element pairs for the Peak and Off Peak scenarios when

the Project was tested as an ERIS.

Table 3-3: LA450S Impacts to Summer Emergency Equipment Loading – ERIS



From

Bus Name kV

To

Bus Name kV

MVA


2019HS

_MPS 2019HS

2019HS

_MPS




From

Bus Name kV

To

Bus Name kV

MVA


2019HS

_MPS 2019HS

2019HS

_MPS

CABALLOT 115 MIMBRES 115 47 Line NEWMAN 345.0 to

AFTON_N 345.0 Circuit 1 81% 81% 108% 107%

LUNA 345 LUNA 115 224 Line LUNA 345.0 to

HIDALGO 345 Circuit 1 82% 82% 108% 109%


AFTON_N 345.0 Circuit 1 86% 86% 109% 103%


AFTON_N 345.0 Circuit 1 92% 92% 106% 105%

Table 3-4: LA450S Impacts to Winter Emergency Equipment Loading – ERIS


2019LW

From

Bus Name kV

To

Bus Name kV

MVA

Rate Contingency Description

Pre-

LA450S

Post-

LA450S

DONA_ANA 115 PICACHO 115 108 Line LUNA 115.0 to

MIMBRES 115 Circuit 1 90% 106%


HIDALGO 345 Circuit 1 75% 101%

3.3 NRIS Network Upgrade Power Flow Testing

In order to address the Project impacts shown in Table 3-3 and

Table 3-4, several different Network Upgrade alternatives were considered. While weighing constraints

such as Right-of-Way issues, installation costs, construction time, and existing contract restrictions, a

single set of Network Upgrades to address LA450S Project impacts was determined. The suggested

Network Upgrades can be described as follows:





terminal

In order to ensure that the proposed Network Upgrades will not cause any new thermal criteria violations,

the Network Upgrades were added to the Study cases then tested under Normal (N-0) and Emergency (N-

1) System Conditions. During the Network Upgrade testing, the proposed Afton North - Anthony 345 kV

line was added to the steady state contingency set.

The proposed Network Upgrade solution is shown in


Figure 3-1 (below). The overloads presented in Section 3.2.2, caused by the addition of LA450S, are

removed after the addition of the Network Upgrades.


Figure 3-1: Year 2019 EPE Transmission System with LA450S POI and Network Upgrades

3.4 ERIS Evaluation

Project generation was reduced until all criteria violation were removed. As Project generation was

reduced, the dispatch was proportionately changed so that the Project served EPE system load and WECC

loads consistent with the 100 MW to 350 MW initial Energy Resource dispatch.

The results in Table 3-5 show the heaviest stressed case as LA450S is reduced to a 250 MW installation.

ERIS overloads caused by the addition of the Project (presented in Section 3.2.3) are removed.

Table 3-5: Post-LA450S Summer Emergency Equipment Loading ERIS 275 vs 250 MW


LA450S @ 275 MW LA450S @ 250 MW

From

Bus Name kV

To

Bus Name kV

MVA


2019HS

_MPS 2019HS

2019HS

_MPS


HIDALGO 345 Circuit 1 105% 105% <100% <100%


AFTON_N 345.0 Circuit 1 101% <100% <100% <100%


AFTON_N 345.0 Circuit 1 101% 100% <100% <100%


3.5 Extreme Outage Protection

Solutions presented in Section above address violations caused by all credible N-1 contingency.

However, EPE and NERC criteria may require LA450S to be taken offline under some N-2 or N-1-1

conditions. More details to be provided in the Facilities Study Report.

3.6 Power Flow Analysis Conclusion

For NRIS, the LA450S Project must include the following set of Network Upgrades:


345/115 kV Transformer (400 MVA).


6. Build Afton North-Anthony 345 kV Line (17.4 miles)

After the addition of the proposed Network Upgrades, Power Flow Analysis Results showed there are no

remaining overloaded facilities, under applicable N-0 or N-1 conditions, caused or worsened by the

addition of the LA450S Project. Please note however that potential curtailment of LA450S under certain

N-2 conditions will be investigated further within the Facilities Study Report.

For ERIS, the LA450S Project can reach a maximum capacity of 250 MW on an as-available basis.


4.0 STEADY STATE VOLTAGE ANALYSIS

Bus voltages within the Study Area were evaluated under both normal and contingency conditions with

and without the LA450S PV generation in service. Please note that the Post-project results discussed

below include the addition of the proposed Network Upgrades in the NRIS evaluation. The results also

assume maximum capacity of LA450S to be 250 MW output in the ERIS evaluation.

The Performance Criteria shown in Error! Reference source not found. were considered when

analyzing bus voltages for violations

4.1 Normal Operating Condition Voltage Evaluation

As studied in both NRIS and ERIS evaluations, the steady state voltage analysis showed no voltage

violations in the El Paso Electric (EPE) and Public Service Company of New Mexico (PNM) areas under

Normal (N-0) system conditions before or after the addition of LA450S generation.

4.2 Emergency Operating Condition Voltage Evaluation

Contingency Voltage analysis was completed by testing the contingencies listed in Appendix B on the

Peak and Off Peak cases both before and after the addition of the Project and relevant Network Upgrades.

As studied in both NRIS and ERIS evaluations, the steady state voltage analysis showed no voltage

violations in the El Paso Electric (EPE) and Public Service Company of New Mexico (PNM) areas under

Emergency (N-1) system conditions before or after the addition of LA450S generation.

4.3 Delta Voltage Evaluation

Bus voltages within the Study Area were evaluated under contingency conditions to determine the change

in voltage due to applicable design contingencies both with and without the LA450S PV generation in

service. The Performance Criteria shown in Error! Reference source not found. were considered when

analyzing bus voltages for violations.

After testing all contingencies listed in Appendix B on, results showed no bus voltages exceed the 7%

Delta Voltage threshold allowed by EPE Performance Criteria.

4.4 Power Factor Test

A power factor test was conducted to show that the LA450S PV generator can maintain a 0.95 pu leading

and lagging power factor at the POI.

Results showed the Project, as designed and operated at full 450 MW output, will continue to absorb vars

past a 0.95 pu leading power factor. However, as seen in the below, the Project inverters can maintain

only a 0.973 pu lagging power factor at the POI which is far short of the 0.95 pu lagging target required

by EPE.

In order to account for reactive loss across the LA450S collector system, an additional 33 Mvar of

capacitors will need to be added at the POI station in order to maintain a 0.95 lagging power factor at the

POI bus.


Table 4-1: Power Factor Test Results

Power Factor Test Results

PF Test

Location

Power Factor

(pu)

POI

Voltage

LA450S

MW

LA450S

Mvar

POI Reactive

(Mvar)

LA450S_POI 0.940 Leading 1.010 450 -117.4 N/A

LA450S_POI 0.973 Lagging 1.039 450 148 N/A

lA450S_POI 0.951 Lagging 1.043 450 148 33.0

4.5 Steady State Voltage Analysis Conclusions

Assuming the Network Upgrades in Section 3.3 are completed to support an NRIS, and assuming an

ERIS maximum capacity of 250 MW on as-available basis, there are no voltage violations caused or

worsened by the addition of the LA450S Project.

However, in order to account for reactive loss across the LA450S collector system, an additional 33 Mvar

of capacitors will need to be added at the POI station in order to maintain a 0.95 lagging power factor at

the LA450S POI.


5.0 SHORT CIRCUIT ANALYSIS

A short circuit analysis was performed to determine if the addition of the LA450S PV generation to the

EPE transmission system would cause any of EPE’s transmission system’s existing substation circuit

breakers to exceed their interrupting capability ratings.

The results below do not include the Network Upgrades described in Section 3.3. Because the Network

Upgrades will consist solely of bus work and a transmission line, they are expected to have only marginal

impact to fault currents and subsequent breaker duty.

5.1 Short Circuit Analysis Modeling

Pre-project and Post-project cases were developed to perform this analysis. As mentioned, any planned

or proposed third party generation listed in EPE’s study queue ahead of LA450S PV generation was also

modeled in the cases. The generator and collector system impedance data used in the study is shown in

Table 5-1.

This analysis evaluated the impact of the LA450S generation by comparing the pre-project and post-

project fault current levels at selected buses.

Table 5-1: Generator Short Circuit Modeling Data

Project

Total

Output

(MW)

Interconnection Customer GSU

Unit

ID

Pmax

(MW)

Qmax

(Mvar)

Qmin

(Mvar)

Z sub-

transient

Rating

(MVA)

Voltage

(kV)

Z

Sub-transient

LA450S 450 1 450 148 -148 0.000 +j0.2 490 345/34.5/13.8 0.002 +j0.01

5.2 Short Circuit Analysis Procedure

The initial short circuit analysis was performed with all other third-party generation projects ahead of the

LA450S generation in the study queue in service and LA450S generation out of service. This identified

the “base case” fault duties of the circuit breakers. The short circuit analysis was performed again with

LA450S generation in service.

Three phase, two phase, two phase to ground, and single-phase line-to-ground faults were simulated at all

buses in the EPE and PNM system. The ASPEN One Liner and Batch Short Circuit Module were used to

perform the short circuit analysis. The short circuit fault analyses were performed with the following

settings:

Transmission line G+jB ignored.

Shunts with positive sequence impedance ignored.

Transformer line shunts ignored

The pre-fault voltage was calculated using a Flat bus voltage of 1.05 per unit.

Fault currents within the EPE System where analyzed before and after the addition of the LA450S

project. Buses that showed an increase of 100 amps or more were reported. These scenarios were then

compared against the smallest breaker interruption ratings at each substation to determine whether any

breaker was over dutied under pre-project or post-project conditions.


5.3 Short Circuit Analysis Results and Conclusion

The results of this short circuit study showed that LA450S project has no significant impact to the fault

currents on the EPE system. The study also showed that the fault currents produced by the LA450S

generation will not exceed the interrupting capability of any existing or proposed circuit breakers on the

EPE system. A complete list of the short circuit results is given in Table 5-2 and Table 5-3 below.

Table 5-2: Short Circuit Analysis Results (Area 10)

Bus Fault On

Lowest

Breaker

Rating

(kA)

Fault

Pre-

project

Current

Post-

project

Current

Delta

(Amperes) (Amperes) (Amperes)

Area 10 (PNM and TSGT)

Afton Gen1 18 3LG 75,437 75,675 238

2LG 75,551 75,709 159

Afton Steam 13.8 3LG 95,567 95,908 341

2LG 92,682 92,895 213

DEMING PLAIN 115

3LG 8,677 8,869 193

2LG 8,726 8,882 155

1LG 8,545 8,656 112

HERMANAS 115 kV 3LG 7,020 7,146 125

HIDALG_XFMR 13.8

kV

3LG 133,035 135,263 2,228

2LG 151,611 153,723 2,112

1LG 158,171 159,448 1,278

HIDALGO 115 kV 40

3LG 17,770 18,012 242

2LG 19,509 19,722 213

1LG 20,311 20,448 137

LEF-GT2 18 kV

3LG 91,092 92,083 991

2LG 88,997 89,616 619

1LG 79,399 79,661 261

LEF-ST1 18 kV

3LG 106,107 108,569 2,461

2LG 99,930 101,368 1,438

1LG 88,098 88,673 575

LUNA 115 kV 20

3LG 10,482 10,777 295

2LG 11,871 12,254 383

1LG 12,189 12,446 257

Luna Energy 345 40

3LG 13,515 15,869 2,354

2LG 13,596 16,214 2,617

1LG 13,430 15,842 2,412

MIMBRES 115 kV 40

3LG 9,134 9,348 213

2LG 9,331 9,513 182

1LG 9,299 9,432 133

XFMR LUNA 13.8 3LG 127,272 133,685 6,413


Bus Fault On

Lowest

Breaker

Rating

(kA)

Fault

Pre-

project

Current

Post-

project

Current

Delta


Area 10 (PNM and TSGT)

2LG 130,269 135,930 5,661

1LG 130,295 134,189 3,894

XFRM2_HIDALG 13.8

kV 3LG 44,162 44,330 168

Table 5-3: Short Circuit Analysis Results (Area 11)

Bus Fault On

Lowest

Breaker

Rating

(kA)

Fault

Pre-

project

Current

Post-

project

Current

Delta


Area 11 (EPE)

AFTON 345 kV 50

3LG 12,978 13,869 891

2LG 12,582 13,609 1,027

1LG 11,811 13,221 1,409

AFTON_N 345 kV 40

ASSUMED

3LG 12,976 13,869 893

2LG 12,571 13,611 1,040

1LG 11,793 13,227 1,434

ANTHONY 115 kV 40 3LG 14,420 14,522 102

ARROYO 115 kV 22 3LG 17,954 18,188 234

2LG 18,324 18,490 166

ARROYO 345 kV 40 3LG 7,841 7,970 128

ASC_CAPBANK 69

kV 31

3LG 25,764 25,904 140

2LG 26,801 26,902 101

ASCARATE 69 kV 40 3LG 25,848 25,989 141

2LG 26,889 26,991 102

ASCARATE 115 kV 22 3LG 21,776 21,946 170

2LG 21,382 21,490 108

AUSTIN 115 kV 20 3LG 22,193 22,368 175

2LG 21,176 21,279 103

BIGGS 115 kV 40 3LG 16,037 16,138 101

Afton North 115 kV 40

ASSUMED

3LG 9,867 10,006 140

2LG 10,176 10,347 171

1LG 10,377 10,570 194

CA200S POI 345 40

ASSUMED

3LG 9,809 10,015 206

2LG 10,028 10,182 154

CALIENTE 115 kV 40 3LG 25,079 25,293 214

2LG 26,396 26,560 164

CALIENTE 345 kV 40 3LG 9,414 9,584 170


Bus Fault On

Lowest

Breaker

Rating

(kA)

Fault

Pre-

project

Current

Post-

project

Current

Delta


Area 11 (EPE)

2LG 9,554 9,676 122

COPPER 115 kV 25 3LG 19,575 19,707 132

CORONA 345 kV 40

ASSUMED

3LG 10,555 10,797 241

2LG 10,809 10,989 181

1LG 10,871 10,980 109

CROMO 115 kV 40 3LG 22,900 23,148 248

2LG 22,090 22,247 157

DIABLO 115 kV 31

3LG 26,272 26,687 415

2LG 26,291 26,626 335

1LG 25,871 26,107 236

DIABLO 345 kV 40

3LG 8,535 8,777 242

2LG 8,189 8,371 182

1LG 7,611 7,750 139

DURAZNO 115 kV 40 3LG 17,181 17,297 116

DYER 115 kV 20 3LG 19,746 19,878 131

EA1 115 kV 40

ASSUMED

3LG 21,446 21,610 164

2LG 20,853 20,955 103

FT_BLISS 115 kV 25 3LG 17,320 17,423 103

GLOBAL_RCH 115 kV 40 3LG 17,258 17,371 113

HIDALGO 345 kV 40

3LG 9,058 9,404 346

2LG 8,556 8,786 229

1LG 7,758 7,900 142

JORNADA 115 kV 40 3LG 11,314 11,416 102

LANE 115 kV 25 3LG 19,867 20,003 136

LAS_CRUC 115 kV 31 3LG 13,390 13,523 133

LUNA 345 kV 40

3LG 13,742 16,246 2,504

2LG 13,721 16,718 2,998

1LG 13,398 16,328 2,930

MACHO_SPRING 345

kV 50

3LG 8,730 9,419 689

2LG 7,976 8,413 438

1LG 5,825 6,208 383

MARLOW 115 kV 31 3LG 21,084 21,243 158

MESA 115 kV 23 3LG 20,631 20,821 190

2LG 19,373 19,484 111

Miner 115 kV 3LG 16,806 16,934 127

MONTOYA 115 kV 20 3LG 15,107 15,217 111


Bus Fault On

Lowest

Breaker

Rating

(kA)

Fault

Pre-

project

Current

Post-

project

Current

Delta


Area 11 (EPE)

MONTWOOD 115 kV 40 3LG 19,083 19,191 108

MPS 115 kV 63 3LG 23,687 23,842 155

2LG 24,985 25,102 117

NEWMAN 115 kV 50

3LG 34,996 35,326 330

2LG 39,945 40,233 288

1LG 41,522 41,684 162

NEWMAN 345 kV 50

3LG 11,465 11,791 327

2LG 11,664 11,906 242

1LG 11,609 11,754 145

Otero_345 345 kV 40

ASSUMED

3LG 9,785 9,990 205

2LG 9,993 10,145 152

P_DODGE 69 kV 3LG 22,942 23,052 110

PATRIOT 115 kV 40 3LG 23,919 24,078 159

2LG 24,062 24,166 104

PENDALE 115 kV 40 3LG 17,932 18,043 111

PICANTE 115 kV 40 3LG 18,523 18,664 141

PICANTE 345 kV 40 3LG 10,040 10,245 204

2LG 10,336 10,491 154

RIO_GRAN 69 kV 40 3LG 21,709 21,839 130

2LG 24,036 24,147 111

RIO_GRAN 115 kV 40

3LG 28,119 28,501 382

2LG 28,884 29,176 292

1LG 29,201 29,368 167

RIPLEY 115 kV 40 3LG 17,797 17,950 153

SALOPEK 115 kV 22 3LG 12,053 12,153 100

SOL 115 kV 40 3LG 18,258 18,375 117

SUNSET_N 115 kV 20 3LG 19,775 19,950 175

THORN 115 kV 20 3LG 15,786 15,907 120

TROWBRIDGE 115 kV

30 3LG 21,209 21,370 161

VISTA 115 kV 25 3LG 19,841 19,982 141

WRANGLER 115 kV 40 3LG 17,207 17,308 101


6.0 STABILITY ANALYSIS

A Transient Stability analysis was performed under Peak and Off Peak load conditions to determine the

degree of impact the Project may have on the EPE system. This analysis evaluated the performance of

the system for selected faults. The purpose of this analysis is to ensure the system has adequate damping

after a fault/trip event.

The analysis compared the system response to the fault simulations before and after the LA450S

generation was added.

The simulations were conducted using the PSLF power flow and dynamic simulation software, General

Electric, Inc. PSLF load flow software package, Version 19 and the associated “DYTools” module.

Dynamic stability simulations were conducted for Peak and Off Peak load conditions with the LA450S

generation off, and on at full capacity.

6.1 Dynamic Modeling

EPE provided the dynamic file data base for this part of the study. The Interconnection Customer

provided the detailed model data sheets and/or parameter values for the LA450S inverters that were added

to the database.

6.2 Stability Study Case Development

The same base cases that were developed for the NRIS and ERIS Steady State evaluations were tested for

any stability violations. (See Section 2.2)

The Pre-Project stability plots for the Peak (MPS On & Off) and Off Peak study cases are provided in

Appendix C. In Appendix C, each study case is presented in a separate set of PDF plots that show

relevant EPE system response to the set of disturbance listed in Error! Reference source not found..

6.3 Preliminary NRIS Stability Analysis

The preliminary analysis was completed using the NRIS cases without Network Upgrades included.

Comparing the preliminary NRIS results in Appendix D1, with the pre-project results in Appendix C,

shows that, EPE system stability was not impacted by adding LA450S at its full 450 MW capacity even

without Network Upgrades included.

The response of the LA450S generator to the set of disturbance listed in Error! Reference source not

found. is also provided at the end of each file in Appendix D and Appendix E. Results show that the unit

remained stable and positively damped for all simulations tested in both NRIS and ERIS analysis.

Table 6-1: Transient Stability Analysis Preliminary Results

Fault Name in

Appendix C /

Appendix D & E

Location Duration Trip Pre-LA450S

ALL CASES

Post-LA450S

ALL CASES

Line 1 / Line 1 Afton North 345

kV 5 cycles Afton North - Newman 345 kV Stable Stable

Line 2 / NA Afton North 345

kV 5 cycles Afton North - Luna 345 kV Stable Stable

NA / Line 20 Afton North 345

kV 5 cycles Afton North - LA450S 345 kV Stable Stable

Bus 3 / Bus 2 Afton 345 kV 5 cycles Loss of all Afton Gen Stable Stable


Fault Name in

Appendix C /

Appendix D & E

Location Duration Trip Pre-LA450S

ALL CASES

Post-LA450S

ALL CASES

Line 4 / Line 3 Afton 345 kV 5 cycles Afton - Diablo 345 KV Stable Stable

Line 5 / Line 4 Diablo 345 kV 5 cycles Afton - Diablo 345 KV Stable Stable

Line 6/Line 5 Hidalgo 345 kV 5 cycles Luna - Hidalgo 345 KV Stable Stable

Line 7/Line 6 Luna 345 kV 5 cycles Luna - LEF 345 KV and LEF Gen Stable Stable

Line 8/NA Luna 345 kV 5 cycles Luna – Afton North 345 kV Stable Stable

NA/Line 19 Luna 345 kV 5 cycles Luna – LA450S 345 kV Stable Stable

Line 9/Line 7 Luna 345 kV 5 cycles Luna - Macho Springs 345 KV Stable Stable

Line 10Line 8 Luna 345 kV 5 cycles Luna - Hidalgo 345 KV Stable Stable

Line 11/ Line 9 Luna 345 kV 5 cycles Luna - LEF 345 KV and LEF Gen Stable Stable

Bus 12/Bus 10 Luna 345 kV 5 cycles Luna 345/115 kV XMFR Stable Stable

Bus 13/Bus 11 Luna 115 kV 5 cycles Luna 345/115 kV XMFR Stable Stable

Line 14/Line 12 Macho Springs

345 kV 5 cycles

Macho Springs - Springville 345

kV Stable Stable

Line 15/Line 13 Macho Springs

345 kV 5 cycles Macho Springs - Luna 345 kV Stable Stable

Bus 16/Bus 14 Newman 345

kV 5 cycles Newman 345/115 kV XMFR #1 Stable Stable

Line 17/Line 15 Newman 345

kV 5 cycles Newman – Afton North 345 kV Stable Stable


kV 5 cycles Newman - Arroyo 345 kV Stable Stable


kV 5 cycles Newman - Corona 345 kV Stable Stable

Line 20/Line 18 Springville 345

kV 5 cycles

Springville - Macho Springs 345 kV

Stable Stable

NA/Line 21 LA450S POI

345 kV 5 cycles LA450S – Luna 345 kV Stable Stable

NA/Line 22 LA450S POI

345 kV 5 cycles LA450S – Afton North 345 KV Stable Stable

NA/Bus 23 LA450S POI

345 kV 5 cycles LA450S 345/34.5 kV XFMR Stable Stable

NA/Bus 24

LA450S POI 345 kV

9 cycles LVRT

N/A Stable Stable

NA/Gen 25 N/A N/A LA450S Generation Stable Stable

6.4 Final NRIS Stability Analysis Results

In order to ensure the Network Upgrades discussed in Section 3.3 address all Project impacts and will not

create any stability concerns, additional stability simulations were completed with the Network Upgrades

included in the NRIS study cases.

The set of disturbances listed in Error! Reference source not found. where again tested with Network

Upgrades in place. Results in Appendix E1 show that LA450S continues to have no adverse impact to

EPE system stability once the Network Upgrades are included.

Outages on the proposed Network Upgrade equipment were also tested. The fault simulations described

in Error! Reference source not found. were included in the NRIS simulation set. Relevant EPE plots

for each fault can be found at the end of each file in Appendix E1.


Table 6-2: Transient Stability Analysis Post-Network Upgrade Results

Fault Name in

Appendix G2 Fault Location

Fault

Duration Trip

Post-LA450S

Network Upgrade

ALL CASES

Line 26 Afton 345 KV 5 cycles Afton – Anthony 345 kV Stable

Line 27 Anthony 345 kV 5 cycles Afton – Anthony 345 kV Stable

Bus 28 Anthony 115 kV 5 cycles Anthony 345/115 kV Stable

Bus 29 Anthony 345 kV 5 cycles Anthony 345/115 kV Stable

Network Upgrade impacts to the response of the LA450S can once again be found at the end of each file

in Appendix E. Results continue show that the unit remained stable and positively damped for all

simulations tested in both NRIS and ERIS analysis both preliminary and final.

6.5 Final ERIS Stability Analysis Results

For the ERIS evaluation, LA450S and EPE system stability were verified on the ERIS case with

maximum Project generation set to 250 MW. Results in Appendix E2 show that LA450S continues to

have no adverse impact to EPE system stability when dispatched to a maximum 250 MW ERIS capacity.

Summary output files are also available for all the simulations created for this SIS report. The summary

report files are in the separate tabs of the Excel document provided as Appendix F.

6.6 Low Voltage Ride Through Test

As shown in Error! Reference source not found., fault name “Bus 24” at LA450S POI tested LA450S

unit response to a 9 cycle Low Voltage Ride Through (LVRT) fault. During the NRIS and ERIS analysis,

this “Bus 24” fault was tested for each case scenario.

The LA450S response to the “Bus 24” LVRT disturbance can be seen in Appendix D and E. The plots

show that the LA450S unit remains online and positively damped through all tested simulations. LA450S

passes all ride through requirements.

6.7 System Inertia Analysis

A high-level system inertia test was completed to determine the impacts of displacing up to 650 MW of

EPE conventional gas generation with proposed PV installations currently in the EPE interconnection

queue.

This analysis was completed by selecting a lightly loaded, high PV penetration study case, then

simulating remote end faults on each of the (3) three 345 kV lines that source EPE. (Afton-Diablo, Afton

North-Newman, Arroyo-West Mesa).

The first case that was tested was the Off Peak (Light Winter) case developed for the NRIS evaluation,

and described in Section 2.2.2 of this report. Six (6) separate simulations were tested to ensure the loss of

an EPE 345 kV line can be withstood. This initial tests did not show a significant drop in frequency or

system collapse in any of the fault simulations.

An additional test was then completed using an off the shelf, WECC case for a 2017 Light Autumn

condition. The Light Autumn WECC case modified by adding only the relevant senior queued EPE

generation (DS90S & CA200S) as well as LA450S generation. (All loads were left as provided in the

approved WECC case.) The 740 MW of senior queued solar generation was used to offset conventional

gas generation in EPE, then the six fault simulations testing outages on the 345 kV lines were tested.


Once again, there was no significant drop in frequency or system collapse in any of the tested fault

simulations using the WECC 2017 Light Autumn case.

To further test the inertia of the system, the Luna Energy Facility (LEF) units were all taken offline in the

WECC 2017 Light Autumn case, and the six different fault simulations were tested again. (The

generation from online LEF units were picked up by turning up generation in the Palo Verde area.) Again,

there was no significant drop in frequency or system collapse in any of the tested fault simulations using

the WECC 2017 Light Autumn case with LEF offline.

The plots in Appendix H show the result of each of the six simulations as tested on the WECC 2017 case

with senior queued generation added and LEF generation offline. The plots are worst case plots of angle,

voltage, and frequency at busses in Areas 10, 11, and 14 for each of the simulated faults. The naming

convention of the fault simulations are listed below.

Appendix H Fault code and locations (all clearing in 5 cycles):

Line 1 = Fault at Newman 345 kV; Clear Newman – Afton North 345 kV

Line 2 = Fault at Afton North 345 kV; Clear Newman – Afton North 345 kV

Line 3 = Fault at Afton 345 kV; Clear Diablo – Afton 345 kV

Line 4 – Fault at Diablo 345 kV; Clear Diablo – Afton 345 kV

Line 5 – Fault at West Mesa 345 kV; Clear West Mesa to Arroyo PST 345 kV

Line 6 - Fault at Arroyo PST 345 kV; Clear West Mesa to Arroyo PST 345 kV

6.8 Stability Analysis Conclusion

Results of both the NRIS and ERIS evaluation show that the EPE system and the LA450S unit remained

stable and positively damped for all simulations tested.


7.0 COST ESTIMATES, ONE-LINES, & PROJECT SCHEDULE

Good faith cost estimates in 2017 dollars (no escalation applied) are presented below. The cost estimates

are based upon costs for previously performed similar construction. These costs include all estimated

applicable labor and overheads associated with the engineering, design, and construction of these new

EPE facilities. These estimates did not include the Generator Interconnection Costs4 for any other

Interconnection Customer owned equipment or associated design and engineering except for the POI and

Network Upgrade facilities.

The estimated total cost for the required upgrades is $58.94 Million for LA450S project. This breaks

down to $0.77 Million for the EPE Interconnection Costs5 at the POI, $9.00 Million for the LA450S POI

Costs, and $49.17 Million for Network Upgrade Costs6. Table 7-1 details the estimated costs for the

LA450S POI. Please note, associated Generator Interconnection Costs have not been estimated as part of

this study.

Table 7-1: Cost Estimate

Project Item

EPE

Interconnection

Substation

Network

Upgrade

Transmission

Network

Upgrade

Total

Cost Cost Cost Cost

(in millions) (in millions) (in millions) (in millions)

LA450S

LA450S

Interconnection

Switching Station

$0.77 $9.00 $0 $9.77

Total LA450S $ 9.77 M

The one-line seen in

4 Generator Interconnection Costs: cost of facilities paid for by Interconnection Customer and owned and

operated by the Interconnection Customer from the generator facilities to the Change of Ownership Point, which

is typically on the first dead-end at the Point of Interconnection substation.

5 EPE Interconnection Costs: cost of facilities paid for by Interconnection Customer but owned and operated by

EPE from the Change of Ownership Point to the Point of Interconnection.

6 Network Upgrades Costs: cost of facilities from the Point of Interconnection outward, paid for by the

interconnector but owned and operated by EPE.


Figure 7-1 shows the POI Substation equipment with a color coded cost responsibility breakdown. The

substation costs for LA450S are given in


Table 7-2.

Element Description Cost Est.

Millions

LA450S POI 345 kV

Substation

Build a new 345 kV three breaker in a Breaker and a Half Scheme Substation. The new

equipment required includes:

Three 345 kV 3000 A circuit breakers

Six 345 kV 2000 A disconnect switches

Two 345 kV 2000 A line disconnect switches w/ grounding

Six sets of CCVT’s and Structures

Six Lightning arresters and Structures

Three sets of Transmission Line Dead-end Assemblies for Substation Dead-end

One lot 345 kV bus, insulators, and structural supports

One lot Transmission line relaying, SCADA, communication, and testing

One lot ground grid, misc. grounding, concrete, conduit, cable trench, and fencing

Relay Setting Changes will also be needed at Chaparral and Oro Grande

$9.00

Estimated Time Frame for Engineering, Procurement, Construction, and Commissioning 29 Months

is a detailed breakdown of the POI substation construction costs.

Figure 7-2 and Figure 7-3 show the Network Upgrades required at Afton North and Anthony Substations

respectively. A detailed breakdown of construction costs are in the subsequent tables.

The Project Schedule in Appendix G provides a more detailed breakdown of the estimated time for

Engineering, Procurement, Construction and Commissioning.


Figure 7-1: LA450S POI Station One Line


Table 7-2: EPE Interconnection Facilities Costs for POI Station (LA450S)


Millions

LA450S EPE Interconnection Facilities located at CA200S POI

One 345 kV 2000 A disconnect switch w/ grounding

One 345 kV Deadend Structure

One set of CCVT’s and Structures

Three Lightning arresters and Structures

One Set of 345 kV 3-Phase Metering Units and structures

Relaying, communication, and testing

$0.770


Table 7-3: EPE Network Upgrade Costs for the LA450S POI Station


Millions

LA450S POI 345 kV

Substation

Build a new 345 kV three breaker in a Breaker and a Half Scheme Substation. The new


Three 345 kV 3000 A circuit breakers

Six 345 kV 2000 A disconnect switches

Two 345 kV 2000 A line disconnect switches w/ grounding

Six sets of CCVT’s and Structures

Six Lightning arresters and Structures

Three sets of Transmission Line Dead-end Assemblies for Substation Dead-end




Relay Setting Changes will also be needed at Chaparral and Oro Grande

$9.00



Figure 7-2: Afton North Switching Station One Line (Network Upgrade)


Figure 7-3: Anthony Substation One-line

.


Table 7-4: EPE Substation Network Upgrade Costs


Millions

Afton North 345 kV

Substation

Expansion

Expand the existing 345 kV Afton North Yard for a new terminal to Anthony. The new


Two 345 kV 3000 A circuit breakers

Five 345 kV 2000 A disconnect switches

One 345 kV 2000 A line disconnect switches w/ grounding

Three sets of CCVT’s and Structures

Three Lightning arresters and Structures

One set of Transmission Line Dead-end Assemblies for Substation Dead-end




$4.81


Anthony 345 kV

Substation Terminal

and 115 kV

Expansion

Expand the existing Anthony 115 kV Substation to add a 345 kV Line Terminal for the

North Afton line, 345 kV Autotransformer and a new connection to the 115 kV bus.

The new equipment required includes:

One 345 kV 3000 A circuit breaker

One 345 kV 2000 A line disconnect switches w/ grounding

Three sets of CCVT’s and Structures

Three 345 kV Lightning arresters and Structures

One 345 kV Substation Deadend

Two 115 kV Substation Deadends

One set of Transmission Line Dead-end Assemblies for Substation Dead-end

One 345/115 kV 400 MVA Autotransformer

Two 115 kV Circuit Breakers

Four 115 kV 3000 Amp Disconnect Switch

Six 115 kV Lightning Arresters and Structures

Six 115 kV CCVT’s and Structures

One lot 345 kV and 115 kV bus, insulators, and structural supports


One lot ground grid, misc. grounding, concrete, conduit, cable trench, and

fencing

$9.88


Table 7-5: EPE Transmission Line Network Upgrades


Millions

Afton North to

Anthony 345 kV

Line

Build a new 17.2 Mile 345 kV line from Afton North to Anthony.

$34.48


LA450S System Impact Study TRC June 2017

41

8.0 DISCLAIMER

If any of the project data provided by Interconnection Customer and used in this study varies significantly

from the actual data of the installed generation equipment for LA450S, the results from this study will

need to be verified with the actual data at the Project Interconnection Customer's expense. Additionally,

any change in the generation in EPE’s Interconnection Queue that is senior to the LA450S may require a

re-evaluation of this Study.


42

9.0 CONCLUSIONS

The results of the NRIS evaluation showed the need for a new, 17.4 mile long, 345 kV transmission line

between Afton and Anthony Substation. In addition to this new 345 kV line a 345/115 kV transformer,

and new 345 kV switchyard is also needed at Anthony.

The required Network Upgrades for CA200S interconnection are as follows:





These reinforcements are required if LA450S is used to serve native EPE load and offset local EPE

conventional generation. Results showed no remaining criteria violations after the addition of these

Network Upgrades.

The results of the ERIS evaluation showed that LA450S can operate at a maximum capacity of 250 MW

on as-available basis before creating a criteria violation. (During ERIS evaluation LA450S generation

was delivered to EPE native load versus WECC loads in New Mexico/Arizona at the requested 1 to 3.5

ratio.)

The estimated cost for integrating the LA450S Project onto the EPE transmission system as an ERIS

Project is $9.77 Million. The good faith estimate for the time frame to Engineer, Procure, and Construct

the POI facilities for an ERIS Project is 39 months, (upon notice to proceed from tine Interconnection

Customer).

The estimated cost for integrating the LA450S Project onto the EPE transmission system as an NRIS

Project is $59.94 Million, including the cost for associated Network Upgrades. The good faith estimate

for the time frame to Engineer, Procure, and Construct all facilities at the POI and the associated Network

Upgrade Substations is 45 months, (upon notice to proceed from tine Interconnection Customer).


43

Appendix A

LA4500S Project Modeling Information


44

Appendix B

Power Flow Contingency List


45

Appendix C

Pre-Project Stability Plots


46

Appendix D

LA450S Preliminary Stability Plots (NRIS and ERIS)


47

Appendix E

LA450S Final Stability Plots (NRIS and ERIS)


48

Appendix F

Stability Run Summary Reports


49

Appendix G

Project Schedule


50

Appendix H

System Inertia Analysis Plots

Documents

SYSTEM IMPACT STUDY REPORT LA450S … report was prepared for the project Interconnection Customer, by ... Table 2-3: Stability Contingencies ... 345/115 kV Transformer (400 MVA)