Post on 07-May-2020
Q217 Generator
Interconnection Project
System Impact Study
APS Contract No. 52588
By
Arizona Public Service Company
Transmission Planning
November 25, 2013 Version 2.0
Prepared by
Utility System Efficiencies, Inc.
Q217 System Impact Study APS Contract No.52588
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Q217 SYSTEM IMPACT STUDY
TABLE OF CONTENTS
EXECUTIVE SUMMARY .................................................................................................................................. 2
1 Study Description and Assumptions ..................................................................................................... 4
1.1 Post Project Case Modeling .......................................................................................................... 4
1.2 Dynamic Data ................................................................................................................................ 7
1.3 Reliability Criteria .......................................................................................................................... 7
1.3.1 Power Factor Criteria ............................................................................................................ 7
1.3.2 (Steady State) Power Flow Criteria ................................................................................. 7
1.3.3 Transient Stability Criteria .................................................................................................... 7
2 Study Methodology ............................................................................................................................... 9
2.1 Power Factor Requirements ......................................................................................................... 9
2.2 Power Flow ................................................................................................................................... 9
2.3 Post-Transient ............................................................................................................................. 10
2.4 Transient Stability ....................................................................................................................... 10
3 Results and Findings ............................................................................................................................ 11
3.1 Reactive Support ......................................................................................................................... 11
3.2 Power Flow and Post-Transient Analysis .................................................................................... 11
3.3 Voltage Flicker Analysis ............................................................................................................... 22
3.4 Transient Stability Analysis ......................................................................................................... 27
3.5 Short Circuit / Fault Duty Analysis .............................................................................................. 28
3.6 Results & Findings Summary ....................................................................................................... 28
4 Cost & Construction Time Estimates .................................................................................................. 28
LIST OF APPENDICES
Appendix A – Power Flow Diagrams Appendix B – List of Contingencies Appendix C – Transient Stability Data Appendix D – Transient Stability Plots
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EXECUTIVE SUMMARY This section summarizes the System Impact Study (SIS) results for a proposed photovoltaic generation interconnection of 35 MW in the Arizona Public Service (APS) transmission system. Additional specific details of the proposed interconnection’s impact on the surrounding transmission system can be found in the “Results and Findings” section of this report. Disclaimer Nothing in this report constitutes an offer of transmission service or confers upon the Interconnection Customer (IC) any right to receive transmission service. APS and other interconnected utilities may not have the Available Transmission Capacity (ATC) to support the interconnection described in this report. It should also be noted that all results for the SIS are highly dependent upon the assumed topology and timing of new projects in the vicinity of the interconnection, which are subject to change. Background: APS received a valid large generator interconnection request for a proposed interconnection to the Desert Sands 69 kV switchyard. On behalf of, and with the oversight of APS, Utility System Efficiencies, Inc. (USE) performed a SIS under the APS Tariff. The interconnection request was assigned queue position #217. The Applicant has proposed to add solar photo-voltaic generation with a maximum net output of 35 MW, connecting directly to the Desert Sands 69 kV switchyard in the second quarter of 2014. A Network & Energy Resource interconnection evaluation was requested. Figure E.1 illustrates this proposed interconnection and the nearby transmission facilities. This SIS used the machine parameters and characteristics provided by the Applicant. Studies consisted of computer-based power flow, post-transient, transient stability, voltage flicker, and short-circuit/fault duty analyses. This study modeled the proposed generation interconnection under anticipated 2014 summer peak conditions. Select contingencies which stressed the transmission system were simulated. Power flow, transient stability, and post-transient results were monitored for APS, WAPA, and other neighboring systems. Voltage Flicker was monitored for the buses in the immediate project area. System performance criteria used in the study: The criteria applied in this study are consistent with NERC/WECC Reliability Criteria. For more detailed information on the criteria used for each analysis see section 1.3 “Reliability Criteria.” The APS Open Access Transmission Tariff (OATT) policy regarding power factor requires all Interconnection Customers, with the exception of wind generators, to maintain an acceptable power factor (typically near unity) at the Point of Interconnection (POI), subject to system conditions. The APS OATT also requires Interconnection Customers to be able to achieve +/- 0.95 power factor at the POI, with the maximum “full-output” Var capability available at all outputs. Furthermore, APS requires Interconnection Customers to have dynamic voltage control (operational time of less than 5 seconds) and maintain the voltage as specified by the transmission operator within the limitation of +/- 0.95 power factor, as long as the Project is online and generating. If the Project’s equipment is not capable of this type of response, a dynamic reactive device will be required. APS has the right to disconnect the Project if system conditions dictate the need to do so in order to maintain system reliability. Results:
The results of the SIS indicate that the addition of Q217 results in no post-project reliability violations.
However, the project as designed is not able to meet the power factor requirements at this time. An
additional 5.5 Mvar reactive support is necessary to compensate for losses from the generator terminals
to the POI.
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Table 1.1 Summary of Project Interconnection Cost and Lead Times
Facility Costs
($000)
Timeline
(months)
Network Upgrades 127 3
Q217 Trans. Provider’s
Interconnection Facilities
1132 18-24
Grand Total 1259 18-24
The total estimated completion time for interconnecting the Q217 project is 18-24 months. The long lead time component for this project is getting Right Of Way from the State of Arizona that will be required for the rebuild of up to two miles of an existing APS 69kv line and the routing of the generator interconnection tie line as it gets set to enter the switchyard. Since the requested interconnection date can’t be met, APS and the Interconnection Customer must discuss and mutually agree to a new and acceptable projected In-Service Date. The customer requested a Network Resource interconnection and as such an evaluation was made and conclusions are that in the 2014 timeframe, APS would be able to accommodate this project as a Network Resource. However, this evaluation result is only good for the time in which it was performed. APS could sell transmission service over the local facilities at any time which could then result in insufficient transmission to accommodate this project as a Network Resource.
Figure E-1. Q217 and Nearby Transmission Facilities
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1 Study Description and Assumptions This section of the report provides details pertaining to the power flow case development and an overview of the major study assumptions. All power flow, voltage flicker, transient stability and post-transient study work was completed using General Electric’s Positive Sequence Load Flow (GE-PSLF), version 18.0_01.
The study used the 2014 Heavy Summer APS detailed planning case “sm14#16.sav”. This case has undergone review and updates by all of the Arizona utilities for planning purposes. Pre- and post-project base cases were developed. The new generation was offset with the Palo Verde (PV) generation group. Sensitivities were run for the following scenarios. Pre- and Post-project cases were developed for each scenario.
1) Max Yuma Load/Generation pattern 2) 2016 Yuma configuration 3) 2016 Yuma configuration with max Yuma Load/Generation pattern 4) 2016 Yuma configuration with max Yuma Load/Generation pattern and TS8 project 5) 2016 Yuma configuration with max Yuma Load/Generation pattern, TS8 project, and Q43 with
max output.
1.1 Post Project Case Modeling Requestor Q217 was represented in the power flow model as a single 35 MW unit connected to a 0.27 kV
bus. A transformer steps the voltage up from 0.27kV to 34.5kV. Another transformer steps the voltage up
from 34.5kV to 69kV. The project was connected via a 1.5 mile 69kV line to Desert Sands 69kV
switchyard. Figure 1-1 represents the Q217 power flow model.
Figure 1-1: Q217 Power Flow Model
Power scheduled to Palo Verde
35 MW
+/-11.99 MVAR
69 kV
34.5 kV
R=0.00283
X=0.08495
1.5 miles
R=0.00713
X=0.05706
Desert Sands 69 kV
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Mesquite generation was reduced to offset the interconnection
Power flow diagrams of the transmission system along with the new generation interconnection are provided in Appendix A. Table 1.2 summarizes the case attributes for each scenario.
Table 1.2 2014 Case Attributes
Major Branch Flows Pre-
Project Post-
Project
Pre-Project
HYL
Post-Project
HYL
Pre-Project
2016 config
Post-Project
2016 config
N.Gila-Gila 69kV 73 78 78 83 56 54
Gila-AR FH TP 69kV 57 57 76 75 0 0
N.Gila-Mittry 69kV 44 38 62 56 53 51
Sanguine-Mittry 69kV -40 -34 -55 -49 -48 -46
Redondo-Sanguine 69kV -2 11 -12 1 -17 -12
Foothill Tap-Redondo 69kV 10 22 6 18 0 0
Foothill Tap-Foothill 69kV -10 -22 -6 -18 0 0
Pacific-N.Gila 69kV -43 -44 -54 -56 -43 -44
Quechan-Pacific 69kV -30 -32 -35 -37 -30 -31
10th St-Quechan 69kV 4 3 16 15 5 4
Sanguine-SW7 69kV 38 44 44 50 31 34
SW7-Ivalon 69kV 38 44 44 50 31 34
Araby-AR FH TP 69kV -57 -57 -75 -75 0 0
MAB-Araby 69kV -29 -29 -34 -33 -33 -35
S.Oneill-MAB 69kV -7 -6 -11 -11 -10 -13
Waldrip-S.Oneill 69kV 18 19 14 14 15 12
Waldrip-Baja 69kV 17 17 22 22 17 18
San Luis-Baja 69kV -6 -7 -6 -6 -6 -7
Laguna-San Luis 69kV 32 32 41 40 32 31
Yuca W-Laguna 69kV 51 51 69 69 51 50
Yuca W-Dupont 69kV 43 41 70 67 44 42
Dupont-32nd St 69kV 29 27 49 46 30 28
10th St-32nd St 69kV 28 27 35 33 30 28
Cocopah-32nd St 69kV 25 23 36 34 26 25
10th St-Cocopah 69kV -14 -13 -28 -27 -15 -14
Riverside-10th St 69kV 43 41 60 58 44 43
Riverside-Cocopah 69kV 32 32 38 38 33 33
Yucca E-Riverside 69kV 28 26 53 51 30 28
Hoodoo Wash-N.Gila 500kV 1,387 1,366 1,054 1,041 1,388 1,367
N.Gila-Imperial Valley 500kV 1,192 1,193 812 821 1,191 1,191
Pilot Knob-Yucca 161kV 14 7 29 22 18 12
Gila-Araby TP-W 69kV 0 0 0 0 35 25
Araby TP-E-Redondo 69kV 0 0 0 0 -5 0
Foothills-Araby S 69kV 0 0 0 0 21 38
Araby N-Araby TP-W 69kV 0 0 0 0 -35 -25
Araby N-Araby TP-E 69kV 0 0 0 0 -5 0
Control Area Information
AZ Load 19,550 19,550 19,724 19,724 19,550 19,550
AZ Lossess 701 701 702 701 700 700
AZ Generation 26,559 26,558 25,934 25,933 26,559 26,558
AZ Exports 6,308 6,308 5,508 5,508 6,308 6,308
Case 1 2 3 4 5 6
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Major Branch Flows
Pre-Project
2016 config/
HYL
Post-Project
2016 config/
HYL
Pre-Project
2016 config/
HYL/TS8
Post-Project
2016 config/
HYL/TS8
Pre-Project 2016 config/ HYL/TS8/Q43
max
Post-Project 2016 config/ HYL/TS8/Q43
max
N.Gila-Gila 69kV 65 64 51 51 52 52
Gila-AR FH TP 69kV 0 0 0 0 0 0
N.Gila-Mittry 69kV 69 67 49 49 49 49
Sanguine-Mittry 69kV -61 -60 -42 -42 -43 -42
Redondo-Sanguine 69kV -22 -18 -12 -10 -12 -10
Foothill Tap-Redondo 69kV 0 0 0 0 0 0
Foothill Tap-Foothill 69kV 0 0 0 0 0 0
Pacific-N.Gila 69kV -54 -55 -41 -43 -42 -43
Quechan-Pacific 69kV -36 -37 -22 -24 -23 -24
10th St-Quechan 69kV 16 15 29 28 29 27
Sanguine-SW7 69kV 39 42 30 32 30 33
SW7-Ivalon 69kV 39 42 30 32 30 32
Araby-AR FH TP 69kV 0 0 0 0 0 0
MAB-Araby 69kV -35 -37 3 -1 3 0
S.Oneill-MAB 69kV -12 -15 -20 -21 -21 -22
Waldrip-S.Oneill 69kV 13 10 5 4 4 3
Waldrip-Baja 69kV 22 22 34 34 34 34
San Luis-Baja 69kV -6 -6 -17 -18 -18 -18
Laguna-San Luis 69kV 41 40 30 30 30 29
Yuca W-Laguna 69kV 69 68 58 57 58 57
Yuca W-Dupont 69kV 71 69 57 56 56 55
Dupont-32nd St 69kV 49 47 36 35 35 34
10th St-32nd St 69kV 36 35 17 17 17 16
Cocopah-32nd St 69kV 37 36 24 23 24 23
10th St-Cocopah 69kV -28 -27 -26 -25 -26 -25
Riverside-10th St 69kV 61 60 57 56 57 56
Riverside-Cocopah 69kV 39 39 37 36 36 36
Yucca E-Riverside 69kV 55 54 48 47 48 47
Hoodoo Wash-N.Gila 500kV 1,055 1,043 690 683 787 779
N.Gila-Imperial Valley 500kV 811 819 876 884 921 930
Pilot Knob-Yucca 161kV 33 26 -12 -16 -13 -18
Gila-Araby TP-W 69kV 58 48 19 12 18 11
Araby TP-E-Redondo 69kV -5 0 5 8 5 8
Foothills-Araby S 69kV 14 31 -2 17 -1 17
Araby N-Araby TP-W 69kV -58 -48 -18 -12 -18 -11
Araby N-Araby TP-E 69kV -4 0 5 8 5 8
Control Area Information
AZ Load 19,724 19,724 19,724 19,724 19,749 19,749
AZ Lossess 703 701 700 698 706 704
AZ Generation 25,934 25,933 25,932 25,930 26,172 26,171
AZ Exports 5,508 5,508 5,508 5,508 5,718 5,718
Case 7 8 9 10 11 12
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1.2 Dynamic Data Appendix C provides the transient stability model used in this study, and the details of these
assumptions. Modeling for the new generation utilized machine characteristics provided by the Applicant.
Dynamic data file “sm14_V2.dyd” (developed by APS) was obtained from APS Transmission Planning. A
stability plot of the flat run simulation is also provided in Appendix D.
1.3 Reliability Criteria In general, an evaluation of the system reliability investigates the system’s thermal loading capability,
voltage performance (not too high or low), and transient stability (the system should not oscillate
excessively and generators should remain synchronized). The evaluation of these criteria must be
conducted for credible ‘emergency’ conditions, such as loss of a single or double circuit line, a
transformer, or a generator. Performance of the transmission system and neighboring Control Areas were
measured against the Western Electricity Coordinating Council (WECC) Reliability Standards and the
North American Electric Reliability Corporation (NERC) Planning Standards described in the following
subsections. The criteria for Category A (TPL-001, “All lines in service”), Category B (TPL-002, single
element outage), and Category C (TPL-003, multiple element outage) conditions were explicitly applied
both internally (within APS system) and to external Control Areas (where appropriate).
1.3.1 Power Factor Criteria The study applies APS power factor criteria states that a generator must be capable of providing dynamic
reactive support within the range of +/-0.95 power factor at the POI.
1.3.2 (Steady State) Power Flow Criteria Normal conditions
All line loading must be less than 100% of the continuous (normal) thermal ratings.
All transformer loading must be less than 100% of the continuous (normal) ratings.
Contingency Conditions
For any contingency, no transmission element will be loaded above the emergency rating.
Depending upon the type of analysis and applied case/sensitivity, applicable criteria for system
performance will be identified. In some instances, resulting local circuit overloads and/or voltage
deviations may be deemed acceptable per local criteria; as long as the local system’s post-
contingency performance does not result in cascading outages.
Established loading limits and voltage performance for other neighboring utilities will be
monitored.
Voltage deviations at any bus must be no more than 5% for N-1 contingencies and no more than
10% for N-2.
1.3.3 Transient Stability Criteria The SIS applies reliability criteria contained within the WECC disturbance-performance table of allowable
effects on other systems. Table 1.3 and Figure 1-2 are excerpts from the WECC Reliability Criteria.
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Table 1.3 WECC Disturbance-Performance Table of Allowable Effects on Other Systems
NERC and WECC Categories
Outage Frequency Associated with the
Performance Category
(outage/year)
Transient Voltage Dip Standard
Minimum Transient Frequency Standard
Post Transient Voltage Deviation Standard
A
System normal Not Applicable Nothing in addition to NERC
B
One element
out-of-service
0.33
Not to exceed 25% at
load buses or 30% at
non-load buses.
Not to exceed 20% for
more than 20 cycles at
load buses.
Not below 59.6Hz for 6
cycles or more at a load
bus.
Not to exceed 5% at any
bus.
C
Two or more
elements
out-of-service
0.033 – 0.33
Not to exceed 30% at
any bus.
Not to exceed 20% for
more than 40 cycles at
load buses.
Not below 59.0Hz for 6
cycles or more at a load
bus.
Not to exceed 10% at
any bus.
D
Extreme multiple-
element outages
< 0.033 Nothing in addition to NERC
Figure 1-2. NERC/WECC Voltage Performance Parameters
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2 Study Methodology This section summarizes the methods used to derive the power flow, post transient, transient stability and
voltage flicker results. Appendix B details the contingencies simulated for the study.
2.1 Power Factor Requirements The APS Open Access Transmission Tariff (OATT) policy regarding power factor requires all
Interconnection Customers, with the exception of wind generators, to maintain an acceptable power factor
(typically near unity) at the Point of Interconnection (POI), subject to system conditions. The APS OATT
also requires Interconnection Customers to be able to achieve +/- 0.95 power factor at the POI, with the
maximum “full-output” Var capability available at all outputs. Furthermore, APS requires Interconnection
Customers to have dynamic voltage control (operational time of less than 5 seconds) and maintain the
voltage as specified by the transmission operator within the limitation of +/- 0.95 power factor, as long as
the Project is online and generating. If the Project’s equipment is not capable of this type of response, a
dynamic reactive device will be required. APS has the right to disconnect the Project from the power grid
if system conditions dictate the need to do so in order to maintain system reliability.
The method for determining whether or not the generator meets these requirements is to first record the
pre-project POI bus voltage. Next, model the generator with zero reactive capabilities at full output. Any
shunt devices are turned off. Two synchronous condensers are added to the case with infinite reactive
capability. One is at the terminal bus of the unit regulating the bus voltage to 1.0 pu. The other is one bus
away from the POI regulating the POI to the pre-project voltage level. The amount of plant losses can be
determined by recording the MVAR flow at the POI and adding that to the sum of the synchronous
condenser output. Based on the maximum output of the plant, determine the minimum reactive
capabilities required to meet the +/-0.95 power factor range. The sum of the two numbers determines the
maximum amount of reactive support the project must provide.
2.2 Power Flow Power flow analysis considers a snapshot in time where the transformer tap changers, SVDs and, the
phase shifters have not adjusted, and the system swing bus balances the system during each
contingency scenario. All power flow analysis was conducted with version 18.0_01 of General Electric’s
PSLF/PSDS/SCSC software. Power flow results are monitored and reported for APS and other
neighboring systems, including WAPA.
Traditional power flow analysis is used to evaluate the thermal and voltage performance of the system
under Category A (TPL-001, all elements in service) and Category B (TPL-002, N-1, single contingency)
conditions. The applicable WECC reliability planning criteria is listed below.
Changes in bus voltages from pre- to post-contingency must be less than 5% for single
contingencies.
All equipment loadings must be below their normal ratings under normal conditions.
All equipment loadings must be below their emergency ratings for single contingencies.
Depending upon the type of analysis and applied case/sensitivity, applicable criteria for system
performance will be identified. In some instances, resulting local circuit overloads and/or voltage
deviations may be deemed acceptable per local criteria; as long as the local system’s post-
contingency performance does not result in cascading outages.
Thermal loading is reported when a modeled transmission element is loaded over 98% of its appropriate
MVA rating modeled in the power flow database.
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Transmission voltage violations for Category A (TPL-001, no contingency) conditions are reported where
per unit voltages are less than 0.95 or greater than 1.05. For Category B outages (TPL-002, N-1) the
voltage violations were reported when the post-contingency voltage deviation was greater than 5%.
2.3 Post-Transient Post-transient analysis determines if the voltage deviations at critical buses meet the maximum allowable
voltage dip criteria and if any transmission elements exceed their maximum rating for selected Category B
(TPL-002, N-1) and Category C (TPL-002, N-2) disturbances. This snapshot focuses on the first few
minutes following an outage where the transformer tap changers, the phase shifters, and SVDs have not
adjusted, and all of the system generation reacts by governor control to balance the system during each
contingency scenario. All loads are modeled as constant power during the Post-Transient time frame.
Generator VAR limits will be modeled as a constant single value for each generator since the reactive
power capability curve will not be modeled in the power flow program. Alpha min and Gamma min of the
PDCI and IPPDC will be adjusted to 5 degrees and 13 degrees, respectively. Shunt capacitors (132
MVAR) at Adelanto and Marketplace will be used if the post-transient voltage deviation exceeds 5% at
those buses.
2.4 Transient Stability
Transient stability analysis is a time-based simulation that assesses the performance of the power system
during (and shortly following) a contingency. Transient stability studies were performed to verify the
system stability following a critical fault on the system. Prior to finalization of the power flow and dynamic
data set, a flat–run is run to ensure true power system behavior is not masked by any remote dynamic
modeling anomalies.
Transient stability analysis was performed based on WECC Disturbance-Performance Criteria for
selected system contingencies. Initial transient stability contingencies are simulated out to 11 seconds to
ensure a damped system performance. All simulated faults are assumed to be three-phase. Table 2.1
identifies the breaker clearing times for faults on different voltage levels.
Table 2.1 Breaker Clearing Times
Voltage Level Breaker
clearing times
69 kV 7-cycles
115/161 kV 6-cycles
230 kV 5-cycles
500 kV 4-cycles
All transient stability simulations were conducted using version 17.0_06 of General Electric’s
PSLF/PSDS/SCSC software.
The Worst Condition Analysis (WCA) tool, available in the PSDS software package, tracks and records
the transient stability behavior of all output channels contained within the binary output file of a transient
stability simulation. The monitoring of channel output was initiated two cycles after fault clearing, to
ensure that all post-fault stability behavior would be captured. System damping was assessed visually
with the aid of stability plots.
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Parameters Monitored to Evaluate System Stability Performance:
Rotor Angle
Rotor angle plots provide a measure for determining how the proposed generation unit would
swing with respect to other generating units in the area. This information is used to determine if a
machine would remain in synchronism or go out-of-step from the rest of the system following a
disturbance.
Bus Voltage
Bus voltage plots, in conjunction with the relative rotor angle plots, provide a means of detecting
out-of-step conditions. The bus voltage plots are useful in assessing the magnitude and duration
of post-disturbance voltage dips and peak-to-peak voltage oscillations. Bus voltage plots also
give an indication of system damping and the level to which voltages are expected to recover in
the steady state conditions.
Bus Frequency
Bus frequency plots provide information on magnitude and duration of post-fault frequency
swings with the new project(s) in service. These plots indicate the extent of possible over-
frequency or under-frequency, which can occur due to an area’s imbalance between load and
generation.
Other plotted Parameters
Generator Terminal Voltage
Generator Rotor Speed
3 Results and Findings This section provides the results obtained by applying the previous assumptions and methodology. It
illustrates all findings associated with the power flow, post-transient, transient stability, and voltage flicker.
3.1 Reactive Support The project satisfies the minimum power factor requirement. The project online at 35 MW requires a
minimum of +/-11.5 MVAR capability at the POI to meet the +/-0.95 power factor requirement. The
calculated plant losses are 6.0 MVAR. The aggregated inverter dynamic capability is +/-11.99 MVAR. The
resultant capability at the POI is 5.99 MVAR. An additional 5.5 Mvar reactive support is required to meet
the APS power factor requirement. A static capacitor bank can be added to compensate for the reactive
losses.
3.2 Power Flow and Post-Transient Analysis The power flow and post-transient analysis focuses on high load and generation conditions for summer of
2014. The Pre-Project cases are used as a baseline to measure the impact of the new generation.
Contingencies are then applied to the cases. A list of contingencies that were simulated is provided in
Appendix B. Power flow plots from the Pre-Project and Post-Project cases are included in Appendix A.
Thermal Results
2014 Heavy Summer Case
Results indicate that there are 2 pre-project violations for this scenario. APS is aware of these and has
mitigation plans to reduce the flow. The addition of the Q217 project does not exacerbate the violation.
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Table 3.1 Thermal Results
Monitored Element Rating (AMPS/MVA)
Pre-Project Post-Project
Amps/MVA % Amps/MVA %
N-1 Yucca E-Yucca C 69 kV
Riverside-Yucca E 69 kV 999.9 A 1153.4 A 115.0 1153.2 A 115.0
N-1 Gila-Sonora 69 kV
San Luis 69/34.5 kV Bank 20 MVA 23.4 MVA 117.0 23.4 MVA 117.0
Case 1 2
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2014 Heavy Summer Case w/High Yuma Load/Gen
Results indicate that there are 8 pre-project violations for this scenario. APS is aware of these and has
mitigation plans to reduce the flow. The addition of the Q217 project does not exacerbate the violation.
Table 3.2 Thermal Results w/High Yuma Generation
Monitored Element Rating (AMPS/MVA)
Pre-Project Post-Project
Amps/MVA % Amps/MVA %
N-1 Yucca E-Yucca C 69 kV
Riverside-Yucca E 69 kV 999.9 A 1126.4 A 112.7 1126.5 A 112.7
N-1 Foothill-Desert Sands 69 kV
Foothill Tap-Redondo 69kV 518.78A 566.4 A 109.2 567.67 A 109.4
N-1 Waldrip-South O'Neill 69 kV
San Luis 69/34.5 kV Bank 20 MVA 20 MVA 100.0 20.1 MVA 100.5
N-1 North Gila-Gila 69 kV
San Luis 69/34.5 kV Bank 20 MVA 21.6 MVA 108.0 21.7 MVA 108.5
N-1 North Gila 500/69 kV 1 or 2
San Luis 69/34.5 kV Bank 20 MVA 20.1 MVA 100.5 20.0 MVA 100.0
N-1 Gila-Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.4 MVA 102.0 20.4 MVA 102.0
N-1 Knob-Pilot Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.6 MVA 103.0 20.6 MVA 103.0
N-1 Gila-Sonora 69 kV
San Luis 69/34.5 kV Bank 20 MVA 29.3 MVA 146.5 29.3 MVA 146.5
Case 3 4
2014 Heavy Summer Case w//2016 configuration
Results indicate that there is 1 pre-project violations for this scenario. APS is aware of these and has
mitigation plans to reduce the flow. The addition of the Q217 project does not exacerbate the violation.
Table 3.3 Thermal Results w/2016 configuration
Monitored Element Rating (AMPS/MVA)
Pre-Project Post-Project
Amps/MVA % Amps/MVA %
N-1 Gila-Sonora 69 kV
San Luis 69/34.5 kV Bank 20 MVA 23.4 MVA 117.0 23.4 MVA 117.0
Case 5 6
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2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen
Results indicate that there are 8 pre-project violations for this scenario. APS is aware of these and has
mitigation plans to reduce the flow. The addition of the Q217 project does not exacerbate the violation.
Table 3.4 Thermal Results w/2016 configuration, High Yuma Generation
Monitored Element Rating (AMPS/MVA)
Pre-Project Post-Project
Amps/MVA % Amps/MVA %
N-1 North Gila-Gila 69 kV
San Luis 69/34.5 kV Bank 20 MVA 20.3 MVA 101.5 20.2 MVA 101.0
N-1 Gila-Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.1 MVA 100.5 19.9 MVA 99.5
N-1 Knob-Pilot Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.2 MVA 101.0 20.1 MVA 100.5
N-1 Gila-Sonora 69 kV
San Luis 69/34.5 kV Bank 20 MVA 29.3 MVA 146.5 29.3 MVA 146.5
Case 7 8
2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen, TS8 project
Results indicate that there are 8 pre-project violations for this scenario. APS is aware of these and has
mitigation plans to reduce the flow. The addition of the Q217 project does not exacerbate the violation.
Table 3.5 Thermal Results w/2016 configuration, High Yuma Generation, TS8 project
Monitored Element Rating (AMPS/MVA)
Pre-Project Post-Project
Amps/MVA % Amps/MVA %
N-1 Tenth St-Quechan 69 kV
San Luis 69/34.5 kV Bank 20 MVA 20.5 MVA 102.5 20.5 MVA 102.5
N-1 North Gila-Gila 69 kV
San Luis 69/34.5 kV Bank 20 MVA 20.8 MVA 104.0 20.8 MVA 104.0
N-1 Araby Bus Tie
San Luis 69/34.5 kV Bank 20 MVA 20.5 MVA 102.5 20.5 MVA 102.5
N-1 North Gila 500/69 kV 1 or 2
San Luis 69/34.5 kV Bank 20 MVA 20.5 MVA 102.5 20.4 MVA 102.0
N-1 Gila-Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.6 MVA 103.0 20.5 MVA 102.5
N-1 Knob-Pilot Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 21.0 MVA 105.0 20.9 MVA 104.5
N-1 Pilot Knob-Yucca 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.4 MVA 102.0 20.5 MVA 102.5
N-1 Gila-Sonora 69 kV
San Luis 69/34.5 kV Bank 20 MVA 29.2 MVA 146.0 29.2 MVA 146.0
Case 9 10
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Page 15
2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen, TS8 project, Q43 full output
Results indicate that there are 8 pre-project violations for this scenario. APS is aware of these and has
mitigation plans to reduce the flow. The addition of the Q217 project does not exacerbate the violation.
Table 3.6 Thermal Results w/2016 configuration, High Yuma Generation, TS8 project, Q43 full
output
Monitored Element Rating (AMPS/MVA)
Pre-Project Post-Project
Amps/MVA % Amps/MVA %
N-1 Tenth St-Quechan 69 kV
San Luis 69/34.5 kV Bank 20 MVA 20.5 MVA 102.5 20.5 MVA 102.5
N-1 North Gila-Gila 69 kV
San Luis 69/34.5 kV Bank 20 MVA 20.8 MVA 104.0 20.8 MVA 104.0
N-1 Araby Bus Tie
San Luis 69/34.5 kV Bank 20 MVA 20.5 MVA 102.5 20.6 MVA 103.0
N-1 Gila-Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.6 MVA 103.0 20.5 MVA 102.5
N-1 Knob-Pilot Knob 161 kV
San Luis 69/34.5 kV Bank 20 MVA 21.0 MVA 105.0 21.0 MVA 105.0
N-1 Pilot Knob-Yucca 161 kV
San Luis 69/34.5 kV Bank 20 MVA 20.5 MVA 102.5 20.5 MVA 102.5
N-1 Gila-Sonora 69 kV
San Luis 69/34.5 kV Bank 20 MVA 29.2 MVA 146.0 29.2 MVA 146.0
Case 11 12
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Page 16
Voltage Results
2014 Heavy Summer Case
Results indicate that there are both pre-project and post-project voltage violations for multiple
contingencies in the Yuma area. This is a known problem to APS planning and mitigation is being
assessed. The addition of the Q217 project does not exacerbate the violations.
Table 3.7 Voltage Results
Monitored Element
Pre-Project Post-Project
% change % change
N-1 Laguna-San Luis 69 kV line
BAJA 69.0 7.00% 7.00%
BOSE 34.5 7.90% 7.90%
SANLUIS 34.5 8.30% 8.20%
SANLUS 3 12.5 8.60% 8.50%
MEX TAP 34.5 7.90% 7.90%
WF_EQLD1 34.5 6.40% 6.40%
SANLUIS 69.0 8.30% 8.20%
WF_EQLD2 34.5 8.10% 8.00%
SNL-WALC 34.5 8.30% 8.20%
BAJA 12.5 7.20% 7.20%
SANLUS11 12.5 9.00% 8.90%
CFE TIE 34.5 8.30% 8.20%
N-1 Yucca-Laguna 69 kV line
BOSE 34.5 5.90% 5.80%
SANLUIS 34.5 6.10% 6.00%
SANLUS 3 12.5 5.50% 5.40%
MEX TAP 34.5 5.90% 5.80%
SANLUIS 69.0 5.30% 5.20%
WF_EQLD2 34.5 6.00% 5.90%
SNL-WALC 34.5 6.10% 6.00%
LAGUNA11 12.5 7.20% 7.10%
LAGUNA 3 12.5 7.20% 7.10%
LAGUNA 69.0 6.90% 6.90%
SANLUS11 12.5 5.70% 5.70%
CFE TIE 34.5 6.10% 6.00%
N-1 Mex Tap-Bose 34.5 kV line
MEX TAP 34.5 -5.00% <5%
N-1 Gila-Sonora 69 kV line
SONORA 69.0 5.70% 5.70%
SNLWALCX 34.5 5.50% 5.50%
Case 1 2
Q217 System Impact Study APS Contract No.52588
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2014 Heavy Summer Case w/High Yuma Load/Gen
Results indicate that there are both pre-project and post-project voltage violations for multiple
contingencies in the Yuma area. This is a known problem to APS planning and mitigation is being
assessed. The addition of the Q217 project does not exacerbate the violations.
Table 3.8 Thermal Results w/High Yuma Generation
Monitored Element
Pre-Project
Post-Project
% change % change
N-1 Laguna-San Luis 69 kV line
BAJA 69.0 8.70% 8.60%
BOSE 34.5 10.50% 10.40%
SANLUIS 34.5 10.70% 10.60%
SNLWALCX 34.5 5.10% <5%
SANLUS 3 12.5 10.80% 10.70%
MEX TAP 34.5 10.50% 10.40%
WF_EQLD1 34.5 8.60% 8.40%
SANLUIS 69.0 10.10% 10.00%
WF_EQLD2 34.5 10.60% 10.50%
SNL-WALC 34.5 10.70% 10.60%
BAJA 12.5 9.20% 9.10%
SANLUS11 12.5 11.00% 10.90%
CFE TIE 34.5 10.70% 10.60%
N-1 Yucca-Laguna 69 kV line
SONORA 69.0 6.00% 5.80%
BAJA 69.0 12.30% 12.00%
BOSE 34.5 15.50% 15.10%
SANLUIS 34.5 15.70% 15.30%
SNLWALCX 34.5 7.80% 7.60%
SANLUS 3 12.5 15.20% 14.80%
MEX TAP 34.5 15.50% 15.10%
WF_EQLD1 34.5 12.90% 12.60%
SANLUIS 69.0 14.10% 13.80%
WF_EQLD2 34.5 15.60% 15.20%
SNL-WALC 34.5 15.70% 15.30%
LAGUNA11 12.5 18.60% 18.20%
BAJA 12.5 13.00% 12.70%
LAGUNA 3 12.5 18.80% 18.40%
LAGUNA 69.0 17.40% 17.10%
SANLUS11 12.5 15.40% 15.00%
CFE TIE 34.5 15.70% 15.30%
N-1 Mex Tap-Bose 34.5 kV line
SANLUIS 34.5 -6.10% -6.10%
MEX TAP 34.5 -8.10% -8.00%
WF_EQLD1 34.5 -6.40% -6.40%
WF_EQLD2 34.5 -7.10% -7.00%
SNL-WALC 34.5 -6.10% -6.10%
CFE TIE 34.5 -6.10% -6.10%
N-1 Gila-Sonora 69 kV line
SONORA 69.0 9.10% 9.10%
SNLWALCX 34.5 8.50% 8.50%
WF_EQLD1 34.5 5.10% 5.10%
Case 3 4
Q217 System Impact Study APS Contract No.52588
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2014 Heavy Summer Case w//2016 configuration
Results indicate that there are both pre-project and post-project voltage violations for multiple
contingencies in the Yuma area. This is a known problem to APS planning and mitigation is being
assessed. The addition of the Q217 project does not exacerbate the violations.
Table 3.9 Voltage Results w/2016 configuration
Monitored Element
Pre-Project
Post-Project
% change % change
N-1 Laguna-San Luis 69 kV line
BAJA 69.0 7.10% 7.00%
BOSE 34.5 8.00% 7.90%
SANLUIS 34.5 8.40% 8.20%
SANLUS 3 12.5 8.70% 8.60%
MEX TAP 34.5 8.00% 7.90%
WF_EQLD1 34.5 6.50% 6.40%
SANLUIS 69.0 8.30% 8.20%
WF_EQLD2 34.5 8.20% 8.00%
SNL-WALC 34.5 8.30% 8.20%
BAJA 12.5 7.30% 7.20%
SANLUS11 12.5 9.00% 8.90%
CFE TIE 34.5 8.40% 8.20%
N-1 Yucca-Laguna 69 kV line
BOSE 34.5 6.00% 5.90%
SANLUIS 34.5 6.20% 6.10%
SANLUS 3 12.5 5.60% 5.50%
MEX TAP 34.5 6.00% 5.90%
SANLUIS 69.0 5.40% 5.30%
WF_EQLD2 34.5 6.10% 6.00%
SNL-WALC 34.5 6.20% 6.10%
LAGUNA11 12.5 7.40% 7.20%
LAGUNA 3 12.5 7.40% 7.20%
LAGUNA 69.0 7.10% 7.00%
SANLUS11 12.5 5.90% 5.70%
CFE TIE 34.5 6.20% 6.10%
N-1 Mex Tap-Bose 34.5 kV line
MEX TAP 34.5 -5.00% <5%
N-1 Gila-Sonora 69 kV line
SONORA 69.0 5.50% 5.50%
SNLWALCX 34.5 5.30% 5.30%
Case 5 6
Q217 System Impact Study APS Contract No.52588
Page 19
2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen
Results indicate that there are both pre-project and post-project voltage violations for multiple
contingencies in the Yuma area. This is a known problem to APS planning and mitigation is being
assessed. The addition of the Q217 project does not exacerbate the violations.
Table 3.10 Volatge Results w/2016 configuration, High Yuma Generation
Monitored Element
Pre-Project
Post-Project
% change % change
N-1 Laguna-San Luis 69 kV line
BAJA 69.0 8.50% 8.50%
BOSE 34.5 10.30% 10.30%
SANLUIS 34.5 10.60% 10.50%
SANLUS 3 12.5 10.70% 10.60%
MEX TAP 34.5 10.30% 10.30%
WF_EQLD1 34.5 8.40% 8.30%
SANLUIS 69.0 10.00% 10.00%
WF_EQLD2 34.5 10.50% 10.40%
SNL-WALC 34.5 10.60% 10.50%
BAJA 12.5 9.00% 9.00%
SANLUS11 12.5 10.90% 10.80%
CFE TIE 34.5 10.60% 10.50%
N-1 Yucca-Laguna 69 kV line
SONORA 69.0 5.50% 5.50%
BAJA 69.0 11.90% 11.80%
BOSE 34.5 15.10% 14.90%
SANLUIS 34.5 15.30% 15.10%
SNLWALCX 34.5 7.40% 7.30%
SANLUS 3 12.5 14.70% 14.50%
MEX TAP 34.5 15.10% 14.90%
WF_EQLD1 34.5 12.50% 12.40%
SANLUIS 69.0 13.70% 13.60%
WF_EQLD2 34.5 15.20% 15.00%
SNL-WALC 34.5 15.30% 15.10%
LAGUNA11 12.5 18.20% 18.00%
BAJA 12.5 12.60% 12.50%
LAGUNA 3 12.5 18.30% 18.10%
LAGUNA 69.0 17.00% 16.80%
SANLUS11 12.5 15.00% 14.80%
CFE TIE 34.5 15.30% 15.10%
N-1 Mex Tap-Bose 34.5 kV line
SANLUIS 34.5 -6.10% -6.10%
MEX TAP 34.5 -8.00% -8.00%
WF_EQLD1 34.5 -6.40% -6.40%
WF_EQLD2 34.5 -7.00% -7.00%
SNL-WALC 34.5 -6.10% -6.10%
CFE TIE 34.5 -6.10% -6.10%
N-1 Gila-Sonora 69 kV line
SONORA 69.0 9.10% 9.10%
SNLWALCX 34.5 8.50% 8.50%
WF_EQLD1 34.5 5.00% 5.00%
Case 7 8
Q217 System Impact Study APS Contract No.52588
Page 20
2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen, TS8 project
Results indicate that there are both pre-project and post-project voltage violations for multiple
contingencies in the Yuma area. This is a known problem to APS planning and mitigation is being
assessed. The addition of the Q217 project does not exacerbate the violations.
Table 3.11 Voltage Results w/2016 configuration, High Yuma Generation, TS8 project
Monitored Element
Pre-Project
Post-Project
% change % change
N-1 Laguna-San Luis 69 kV line
BAJA 69.0 6.20% 6.20%
BOSE 34.5 7.30% 7.30%
SANLUIS 34.5 7.60% 7.50%
SANLUS 3 12.5 7.90% 7.90%
MEX TAP 34.5 7.30% 7.30%
WF_EQLD1 34.5 5.90% 5.90%
SANLUIS 69.0 7.40% 7.40%
WF_EQLD2 34.5 7.50% 7.40%
SNL-WALC 34.5 7.60% 7.50%
BAJA 12.5 6.50% 6.50%
SANLUS11 12.5 8.00% 8.00%
CFE TIE 34.5 7.60% 7.50%
N-1 Yucca-Laguna 69 kV line
BAJA 69.0 7.00% 6.90%
BOSE 34.5 8.90% 8.80%
SANLUIS 34.5 9.10% 9.00%
SANLUS 3 12.5 8.70% 8.60%
MEX TAP 34.5 8.90% 8.80%
WF_EQLD1 34.5 7.30% 7.20%
SANLUIS 69.0 8.20% 8.10%
WF_EQLD2 34.5 9.00% 8.90%
SNL-WALC 34.5 9.10% 9.00%
LAGUNA11 12.5 11.30% 11.20%
BAJA 12.5 7.40% 7.30%
LAGUNA 3 12.5 11.40% 11.30%
LAGUNA 69.0 10.60% 10.60%
SANLUS11 12.5 8.80% 8.80%
CFE TIE 34.5 9.10% 9.00%
N-1 Mex Tap-Bose 34.5 kV line
SANLUIS 34.5 -5.70% -5.70%
MEX TAP 34.5 -7.60% -7.60%
WF_EQLD1 34.5 -6.00% -6.00%
WF_EQLD2 34.5 -6.60% -6.60%
SNL-WALC 34.5 -5.70% -5.70%
CFE TIE 34.5 -5.70% -5.70%
N-1 Gila-Sonora 69 kV line
SONORA 69.0 8.50% 8.40%
SNLWALCX 34.5 7.90% 7.90%
Case 9 10
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2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen, TS8 project, Q43 full output
Results indicate that there are both pre-project and post-project voltage violations for multiple
contingencies in the Yuma area. This is a known problem to APS planning and mitigation is being
assessed. The addition of the Q217 project does not exacerbate the violations.
Table 3.12 Voltage Results w/2016 configuration, High Yuma Generation, TS8 project, Q43 full
output
Monitored Element
Pre-Project
Post-Project
% change % change
N-1 Laguna-San Luis 69 kV line
BAJA 69.0 6.20% 6.20%
BOSE 34.5 7.30% 7.40%
SANLUIS 34.5 7.60% 7.60%
SANLUS 3 12.5 7.90% 7.90%
MEX TAP 34.5 7.30% 7.40%
WF_EQLD1 34.5 5.90% 5.90%
SANLUIS 69.0 7.40% 7.40%
WF_EQLD2 34.5 7.50% 7.50%
SNL-WALC 34.5 7.60% 7.60%
BAJA 12.5 6.50% 6.50%
SANLUS11 12.5 8.00% 8.10%
CFE TIE 34.5 7.60% 7.60%
N-1 Yucca-Laguna 69 kV line
BAJA 69.0 7.00% 7.00%
BOSE 34.5 8.80% 8.90%
SANLUIS 34.5 9.00% 9.10%
SANLUS 3 12.5 8.70% 8.70%
MEX TAP 34.5 8.80% 8.90%
WF_EQLD1 34.5 7.20% 7.20%
SANLUIS 69.0 8.20% 8.20%
WF_EQLD2 34.5 8.90% 9.00%
SNL-WALC 34.5 9.00% 9.10%
LAGUNA11 12.5 11.30% 11.40%
BAJA 12.5 7.30% 7.40%
LAGUNA 3 12.5 11.40% 11.40%
LAGUNA 69.0 10.70% 10.70%
SANLUS11 12.5 8.80% 8.90%
CFE TIE 34.5 9.00% 9.10%
N-1 Mex Tap-Bose 34.5 kV line
SANLUIS 34.5 -5.70% -5.70%
MEX TAP 34.5 -7.60% -7.60%
WF_EQLD1 34.5 -6.00% -6.00%
WF_EQLD2 34.5 -6.60% -6.60%
SNL-WALC 34.5 -5.70% -5.70%
CFE TIE 34.5 -5.70% -5.70%
N-1 Gila-Sonora 69 kV line
SONORA 69.0 8.40% 8.40%
SNLWALCX 34.5 7.90% 7.90%
Case 11 12
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Page 22
3.3 Voltage Flicker Analysis 2014 Heavy Summer Case
Results of the voltage flicker analysis indicate that there are no deviations greater than 1.5%. Table 3.13
details the results of the voltage flicker analysis. The greatest flicker is observed at the Foothills 69.0 kV
bus with a 0.2978% decrease with Q217. This occurs as the unit(s) adjusts from 100% to 10% output.
Table 3.13 Voltage Flicker Results, Q217
100% Generation (base) 10% Generation 30% Generation 60% Generation 90% Generation
Bus Voltage
(pu) Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation
FOOTHILS 69.00kV 0.9987 0.9957 -0.2978 0.9979 -0.0839 0.9995 0.0792 0.9992 0.0523
N.GILA 69.00kV 1.0143 1.0137 -0.059 1.0147 0.0374 1.0152 0.093 1.0147 0.0415
REDONDO 69.00kV 1.0003 0.999 -0.1344 1.0004 0.0104 1.0014 0.1048 1.0008 0.0515
MITTRY 69.00kV 1.0107 1.0099 -0.0783 1.011 0.0272 1.0116 0.0913 1.0111 0.0422
ARABY S 69.00kV 1.0084 1.0077 -0.073 1.0085 0.009 1.009 0.0616 1.0087 0.0298
MAB S 69.00kV 1.002 1.0013 -0.0687 1.002 0.0086 1.0025 0.0582 1.0022 0.0281
SANGUINE 69.00kV 1.0023 1.0013 -0.1039 1.0025 0.0205 1.0033 0.0989 1.0028 0.047
GILA 69.00kV 1.0111 1.0104 -0.0683 1.0112 0.0125 1.0117 0.0636 1.0114 0.0303
SONEILL 69.00kV 1.0008 1.0001 -0.0648 1.0009 0.0101 1.0013 0.0577 1.001 0.0277
PACIFIC 69.00kV 1.0071 1.0067 -0.0386 1.0074 0.0307 1.0078 0.0698 1.0074 0.0308
SW7 69.00kV 1.0014 1.0006 -0.0777 1.0017 0.0314 1.0024 0.097 1.0019 0.0444
QUECHAN 69.00kV 1.0073 1.0069 -0.0384 1.0076 0.0259 1.008 0.0627 1.0076 0.0279
WALDRIP 69.00kV 1.0014 1.0008 -0.0611 1.0015 0.0112 1.002 0.0569 1.0017 0.0271
SANLUIS 69.00kV 0.9937 0.9931 -0.0625 0.9938 0.0048 0.9942 0.0486 0.994 0.0238
LAGUNA 69.00kV 1.0255 1.0251 -0.0456 1.0256 0.0087 1.026 0.0429 1.0258 0.0204
FOOTHILS 69.00kV 0.9987 0.9957 -0.2978 0.9979 -0.0839 0.9995 0.0792 0.9992 0.0523
N.GILA 69.00kV 1.0143 1.0137 -0.059 1.0147 0.0374 1.0152 0.093 1.0147 0.0415
REDONDO 69.00kV 1.0003 0.999 -0.1344 1.0004 0.0104 1.0014 0.1048 1.0008 0.0515
MITTRY 69.00kV 1.0107 1.0099 -0.0783 1.011 0.0272 1.0116 0.0913 1.0111 0.0422
ARABY S 69.00kV 1.0084 1.0077 -0.073 1.0085 0.009 1.009 0.0616 1.0087 0.0298
MAB S 69.00kV 1.002 1.0013 -0.0687 1.002 0.0086 1.0025 0.0582 1.0022 0.0281
SANGUINE 69.00kV 1.0023 1.0013 -0.1039 1.0025 0.0205 1.0033 0.0989 1.0028 0.047
GILA 69.00kV 1.0111 1.0104 -0.0683 1.0112 0.0125 1.0117 0.0636 1.0114 0.0303
SONEILL 69.00kV 1.0008 1.0001 -0.0648 1.0009 0.0101 1.0013 0.0577 1.001 0.0277
PACIFIC 69.00kV 1.0071 1.0067 -0.0386 1.0074 0.0307 1.0078 0.0698 1.0074 0.0308
SW7 69.00kV 1.0014 1.0006 -0.0777 1.0017 0.0314 1.0024 0.097 1.0019 0.0444
QUECHAN 69.00kV 1.0073 1.0069 -0.0384 1.0076 0.0259 1.008 0.0627 1.0076 0.0279
WALDRIP 69.00kV 1.0014 1.0008 -0.0611 1.0015 0.0112 1.002 0.0569 1.0017 0.0271
SANLUIS 69.00kV 0.9937 0.9931 -0.0625 0.9938 0.0048 0.9942 0.0486 0.994 0.0238
Q217 System Impact Study APS Contract No.52588
Page 23
2014 Heavy Summer Case w/High Yuma Load/Gen
Results of the voltage flicker analysis indicate that there are no deviations greater than 1.5%. Table 3.14
details the results of the voltage flicker analysis. The greatest flicker is observed at the Foothills 69.0 kV
bus with a 0.5345% decrease with Q217. This occurs as the unit(s) adjusts from 100% to 10% output.
Table 3.14 Voltage Flicker Results, Q217
100% Generation (base) 10% Generation 30% Generation 60% Generation 90% Generation
Bus Voltage
(pu) Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation
FOOTHILS 69.00kV 1.0025 0.9971 -0.5345 0.9998 -0.2688 1.0022 -0.0283 1.0027 0.0248
N.GILA 69.00kV 1.0115 1.0088 -0.2667 1.0102 -0.1277 1.0115 -0.0053 1.0117 0.0158
REDONDO 69.00kV 0.9962 0.9926 -0.3548 0.9945 -0.1643 0.9962 0.0013 0.9964 0.0245
MITTRY 69.00kV 1.0067 1.0037 -0.2902 1.0052 -0.1413 1.0066 -0.0089 1.0068 0.0159
ARABY S 69.00kV 0.9971 0.9947 -0.2433 0.9959 -0.1286 0.9969 -0.022 0.9972 0.0075
MAB S 69.00kV 0.9886 0.9865 -0.2135 0.9875 -0.1127 0.9884 -0.0192 0.9886 0.0066
SANGUINE 69.00kV 0.9959 0.9928 -0.311 0.9945 -0.145 0.9959 -0.0003 0.9961 0.0209
GILA 69.00kV 1.0025 1.0001 -0.2394 1.0012 -0.1253 1.0023 -0.02 1.0025 0.0081
SONEILL 69.00kV 0.9869 0.985 -0.2007 0.9859 -0.1054 0.9868 -0.0171 0.987 0.0066
PACIFIC 69.00kV 0.993 0.9914 -0.1606 0.9923 -0.0764 0.993 -0.0023 0.9931 0.0098
SW7 69.00kV 0.9921 0.9895 -0.2637 0.9909 -0.1193 0.9921 0.0049 0.9923 0.0198
QUECHAN 69.00kV 0.992 0.9906 -0.1421 0.9913 -0.0689 0.992 -0.0041 0.9921 0.0079
WALDRIP 69.00kV 0.9872 0.9853 -0.1877 0.9862 -0.098 0.987 -0.0152 0.9873 0.0065
SANLUIS 69.00kV 0.9769 0.9751 -0.1827 0.976 -0.0993 0.9767 -0.0205 0.977 0.0041
LAGUNA 69.00kV 1.0106 1.0092 -0.1386 1.0099 -0.0751 1.0105 -0.0152 1.0107 0.0032
FOOTHILS 69.00kV 1.0025 0.9971 -0.5345 0.9998 -0.2688 1.0022 -0.0283 1.0027 0.0248
N.GILA 69.00kV 1.0115 1.0088 -0.2667 1.0102 -0.1277 1.0115 -0.0053 1.0117 0.0158
REDONDO 69.00kV 0.9962 0.9926 -0.3548 0.9945 -0.1643 0.9962 0.0013 0.9964 0.0245
MITTRY 69.00kV 1.0067 1.0037 -0.2902 1.0052 -0.1413 1.0066 -0.0089 1.0068 0.0159
ARABY S 69.00kV 0.9971 0.9947 -0.2433 0.9959 -0.1286 0.9969 -0.022 0.9972 0.0075
MAB S 69.00kV 0.9886 0.9865 -0.2135 0.9875 -0.1127 0.9884 -0.0192 0.9886 0.0066
SANGUINE 69.00kV 0.9959 0.9928 -0.311 0.9945 -0.145 0.9959 -0.0003 0.9961 0.0209
GILA 69.00kV 1.0025 1.0001 -0.2394 1.0012 -0.1253 1.0023 -0.02 1.0025 0.0081
SONEILL 69.00kV 0.9869 0.985 -0.2007 0.9859 -0.1054 0.9868 -0.0171 0.987 0.0066
PACIFIC 69.00kV 0.993 0.9914 -0.1606 0.9923 -0.0764 0.993 -0.0023 0.9931 0.0098
SW7 69.00kV 0.9921 0.9895 -0.2637 0.9909 -0.1193 0.9921 0.0049 0.9923 0.0198
QUECHAN 69.00kV 0.992 0.9906 -0.1421 0.9913 -0.0689 0.992 -0.0041 0.9921 0.0079
WALDRIP 69.00kV 0.9872 0.9853 -0.1877 0.9862 -0.098 0.987 -0.0152 0.9873 0.0065
SANLUIS 69.00kV 0.9769 0.9751 -0.1827 0.976 -0.0993 0.9767 -0.0205 0.977 0.0041
Q217 System Impact Study APS Contract No.52588
Page 24
2014 Heavy Summer Case w//2016 configuration
Results of the voltage flicker analysis indicate that there are no deviations greater than 1.5%. Table 3.15
details the results of the voltage flicker analysis. The greatest flicker is observed at the Foothills 69.0 kV
bus with a 0.2581% decrease with Q217. This occurs as the unit(s) adjusts from 100% to 10% output.
Table 3.15 Voltage Flicker Results, Q217
100% Generation (base) 10% Generation 30% Generation 60% Generation 90% Generation
Bus Voltage
(pu) Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation
FOOTHILS 69.00kV 1.0016 0.9991 -0.2581 1.0008 -0.0826 1.0022 0.0544 1.002 0.0395
N.GILA 69.00kV 1.0152 1.0138 -0.1323 1.0149 -0.0279 1.0157 0.0485 1.0155 0.0285
REDONDO 69.00kV 1.004 1.0026 -0.1327 1.0038 -0.0201 1.0046 0.06 1.0043 0.0332
MITTRY 69.00kV 1.012 1.0106 -0.1353 1.0117 -0.0295 1.0125 0.0483 1.0123 0.0286
ARABY S 69.00kV 1.004 1.0022 -0.1832 1.0035 -0.0489 1.0046 0.0526 1.0044 0.0336
MAB S 69.00kV 0.9998 0.9984 -0.1402 0.9994 -0.0342 1.0002 0.0448 1 0.0276
SANGUINE 69.00kV 1.005 1.0037 -0.1301 1.0048 -0.0238 1.0056 0.0529 1.0053 0.0301
GILA 69.00kV 1.0081 1.0067 -0.1396 1.0078 -0.0295 1.0086 0.0511 1.0084 0.03
SONEILL 69.00kV 0.9993 0.9979 -0.1383 0.9989 -0.0388 0.9997 0.037 0.9996 0.0243
PACIFIC 69.00kV 1.0078 1.0067 -0.1037 1.0075 -0.0251 1.0081 0.0334 1.008 0.0205
SW7 69.00kV 1.0038 1.0026 -0.122 1.0036 -0.0229 1.0043 0.0487 1.0041 0.0279
QUECHAN 69.00kV 1.0079 1.0069 -0.1001 1.0076 -0.0266 1.0082 0.0288 1.0081 0.0184
WALDRIP 69.00kV 1.0007 0.9994 -0.1347 1.0003 -0.0421 1.001 0.0297 1.0009 0.0211
SANLUIS 69.00kV 0.9934 0.992 -0.1331 0.9929 -0.0478 0.9936 0.0205 0.9935 0.0173
LAGUNA 69.00kV 1.0254 1.0244 -0.0974 1.0251 -0.031 1.0256 0.0207 1.0256 0.0149
FOOTHILS 69.00kV 1.0016 0.9991 -0.2581 1.0008 -0.0826 1.0022 0.0544 1.002 0.0395
N.GILA 69.00kV 1.0152 1.0138 -0.1323 1.0149 -0.0279 1.0157 0.0485 1.0155 0.0285
REDONDO 69.00kV 1.004 1.0026 -0.1327 1.0038 -0.0201 1.0046 0.06 1.0043 0.0332
MITTRY 69.00kV 1.012 1.0106 -0.1353 1.0117 -0.0295 1.0125 0.0483 1.0123 0.0286
ARABY S 69.00kV 1.004 1.0022 -0.1832 1.0035 -0.0489 1.0046 0.0526 1.0044 0.0336
MAB S 69.00kV 0.9998 0.9984 -0.1402 0.9994 -0.0342 1.0002 0.0448 1 0.0276
SANGUINE 69.00kV 1.005 1.0037 -0.1301 1.0048 -0.0238 1.0056 0.0529 1.0053 0.0301
GILA 69.00kV 1.0081 1.0067 -0.1396 1.0078 -0.0295 1.0086 0.0511 1.0084 0.03
SONEILL 69.00kV 0.9993 0.9979 -0.1383 0.9989 -0.0388 0.9997 0.037 0.9996 0.0243
PACIFIC 69.00kV 1.0078 1.0067 -0.1037 1.0075 -0.0251 1.0081 0.0334 1.008 0.0205
SW7 69.00kV 1.0038 1.0026 -0.122 1.0036 -0.0229 1.0043 0.0487 1.0041 0.0279
QUECHAN 69.00kV 1.0079 1.0069 -0.1001 1.0076 -0.0266 1.0082 0.0288 1.0081 0.0184
WALDRIP 69.00kV 1.0007 0.9994 -0.1347 1.0003 -0.0421 1.001 0.0297 1.0009 0.0211
SANLUIS 69.00kV 0.9934 0.992 -0.1331 0.9929 -0.0478 0.9936 0.0205 0.9935 0.0173
Q217 System Impact Study APS Contract No.52588
Page 25
2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen
Results of the voltage flicker analysis indicate that there are no deviations greater than 1.5%. Table 3.16
details the results of the voltage flicker analysis. The greatest flicker is observed at the Foothills 69.0 kV
bus with a 0.4370% decrease with Q217. This occurs as the unit(s) adjusts from 100% to 10% output.
Table 3.16 Voltage Flicker Results, Q217
100% Generation (base) 10% Generation 30% Generation 60% Generation 90% Generation
Bus Voltage
(pu) Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation
FOOTHILS 69.00kV 1.0011 0.9967 -0.437 0.9988 -0.2237 1.0008 -0.0286 1.0012 0.018
N.GILA 69.00kV 1.0117 1.0086 -0.303 1.01 -0.1643 1.0113 -0.0331 1.0117 0.0071
REDONDO 69.00kV 0.9947 0.9918 -0.2913 0.9932 -0.1479 0.9945 -0.0175 0.9948 0.0126
MITTRY 69.00kV 1.0064 1.0034 -0.3027 1.0048 -0.1636 1.0061 -0.0324 1.0065 0.0073
ARABY S 69.00kV 0.9976 0.9941 -0.3545 0.9958 -0.1855 0.9974 -0.029 0.9978 0.0122
MAB S 69.00kV 0.9887 0.986 -0.268 0.9873 -0.1409 0.9885 -0.023 0.9888 0.0088
SANGUINE 69.00kV 0.9949 0.9921 -0.2805 0.9934 -0.1461 0.9947 -0.0221 0.995 0.01
GILA 69.00kV 1.0029 0.9998 -0.308 1.0012 -0.164 1.0026 -0.0294 1.003 0.0089
SONEILL 69.00kV 0.987 0.9845 -0.2532 0.9857 -0.1366 0.9868 -0.0267 0.9871 0.0063
PACIFIC 69.00kV 0.9931 0.9912 -0.1916 0.992 -0.1049 0.9929 -0.0224 0.9931 0.0039
SW7 69.00kV 0.9914 0.9888 -0.2562 0.9901 -0.134 0.9912 -0.0209 0.9915 0.0088
QUECHAN 69.00kV 0.992 0.9904 -0.1698 0.9911 -0.0942 0.9918 -0.0216 0.9921 0.0027
WALDRIP 69.00kV 0.9873 0.9849 -0.2368 0.986 -0.1311 0.987 -0.0298 0.9873 0.004
SANLUIS 69.00kV 0.9771 0.9749 -0.2328 0.9758 -0.1346 0.9768 -0.0374 0.9771 0.0006
LAGUNA 69.00kV 1.0108 1.0091 -0.1705 1.0098 -0.0983 1.0105 -0.0271 1.0108 0.0006
FOOTHILS 69.00kV 1.0011 0.9967 -0.437 0.9988 -0.2237 1.0008 -0.0286 1.0012 0.018
N.GILA 69.00kV 1.0117 1.0086 -0.303 1.01 -0.1643 1.0113 -0.0331 1.0117 0.0071
REDONDO 69.00kV 0.9947 0.9918 -0.2913 0.9932 -0.1479 0.9945 -0.0175 0.9948 0.0126
MITTRY 69.00kV 1.0064 1.0034 -0.3027 1.0048 -0.1636 1.0061 -0.0324 1.0065 0.0073
ARABY S 69.00kV 0.9976 0.9941 -0.3545 0.9958 -0.1855 0.9974 -0.029 0.9978 0.0122
MAB S 69.00kV 0.9887 0.986 -0.268 0.9873 -0.1409 0.9885 -0.023 0.9888 0.0088
SANGUINE 69.00kV 0.9949 0.9921 -0.2805 0.9934 -0.1461 0.9947 -0.0221 0.995 0.01
GILA 69.00kV 1.0029 0.9998 -0.308 1.0012 -0.164 1.0026 -0.0294 1.003 0.0089
SONEILL 69.00kV 0.987 0.9845 -0.2532 0.9857 -0.1366 0.9868 -0.0267 0.9871 0.0063
PACIFIC 69.00kV 0.9931 0.9912 -0.1916 0.992 -0.1049 0.9929 -0.0224 0.9931 0.0039
SW7 69.00kV 0.9914 0.9888 -0.2562 0.9901 -0.134 0.9912 -0.0209 0.9915 0.0088
QUECHAN 69.00kV 0.992 0.9904 -0.1698 0.9911 -0.0942 0.9918 -0.0216 0.9921 0.0027
WALDRIP 69.00kV 0.9873 0.9849 -0.2368 0.986 -0.1311 0.987 -0.0298 0.9873 0.004
SANLUIS 69.00kV 0.9771 0.9749 -0.2328 0.9758 -0.1346 0.9768 -0.0374 0.9771 0.0006
Q217 System Impact Study APS Contract No.52588
Page 26
2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen, TS8 project
Results of the voltage flicker analysis indicate that there are no deviations greater than 1.5%. Table 3.17
details the results of the voltage flicker analysis. The greatest flicker is observed at the Foothills 69.0 kV
bus with a 0.2137% decrease with Q217. This occurs as the unit(s) adjusts from 100% to 10% output.
Table 3.17 Voltage Flicker Results, Q217
100% Generation (base) 10% Generation 30% Generation 60% Generation 90% Generation
Bus Voltage
(pu) Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation
FOOTHILS 69.00kV 1.0122 1.01 -0.2137 1.0115 -0.0697 1.0126 0.0432 1.0125 0.032
N.GILA 69.00kV 1.0201 1.0193 -0.0759 1.0201 -0.001 1.0206 0.0492 1.0204 0.025
REDONDO 69.00kV 1.0061 1.0052 -0.0891 1.006 -0.0073 1.0066 0.0491 1.0064 0.0258
MITTRY 69.00kV 1.0157 1.0149 -0.0786 1.0157 -0.0031 1.0162 0.0481 1.0159 0.0247
ARABY S 69.00kV 1.0102 1.0088 -0.1321 1.0098 -0.0335 1.0106 0.0403 1.0104 0.0252
MAB S 69.00kV 1.0083 1.0072 -0.1172 1.0079 -0.0402 1.0086 0.0207 1.0085 0.0163
SANGUINE 69.00kV 1.006 1.0052 -0.0824 1.0059 -0.0063 1.0065 0.046 1.0062 0.0241
GILA 69.00kV 1.0128 1.012 -0.0806 1.0128 -0.004 1.0133 0.0481 1.0131 0.0248
SONEILL 69.00kV 1.0061 1.005 -0.1101 1.0058 -0.0376 1.0063 0.0198 1.0063 0.0154
PACIFIC 69.00kV 1.0016 1.001 -0.0594 1.0015 -0.0056 1.0019 0.0316 1.0017 0.0168
SW7 69.00kV 1.0026 1.0018 -0.0763 1.0025 -0.0059 1.003 0.0425 1.0028 0.0223
QUECHAN 69.00kV 1.0002 0.9996 -0.0593 1.0001 -0.0095 1.0005 0.026 1.0004 0.0145
WALDRIP 69.00kV 1.0058 1.0047 -0.1027 1.0054 -0.0348 1.006 0.0188 1.0059 0.0145
SANLUIS 69.00kV 0.9916 0.9907 -0.0878 0.9913 -0.0283 0.9918 0.0182 0.9917 0.0133
LAGUNA 69.00kV 1.0205 1.0199 -0.0608 1.0203 -0.0166 1.0207 0.0168 1.0206 0.0109
FOOTHILS 69.00kV 1.0122 1.01 -0.2137 1.0115 -0.0697 1.0126 0.0432 1.0125 0.032
N.GILA 69.00kV 1.0201 1.0193 -0.0759 1.0201 -0.001 1.0206 0.0492 1.0204 0.025
REDONDO 69.00kV 1.0061 1.0052 -0.0891 1.006 -0.0073 1.0066 0.0491 1.0064 0.0258
MITTRY 69.00kV 1.0157 1.0149 -0.0786 1.0157 -0.0031 1.0162 0.0481 1.0159 0.0247
ARABY S 69.00kV 1.0102 1.0088 -0.1321 1.0098 -0.0335 1.0106 0.0403 1.0104 0.0252
MAB S 69.00kV 1.0083 1.0072 -0.1172 1.0079 -0.0402 1.0086 0.0207 1.0085 0.0163
SANGUINE 69.00kV 1.006 1.0052 -0.0824 1.0059 -0.0063 1.0065 0.046 1.0062 0.0241
GILA 69.00kV 1.0128 1.012 -0.0806 1.0128 -0.004 1.0133 0.0481 1.0131 0.0248
SONEILL 69.00kV 1.0061 1.005 -0.1101 1.0058 -0.0376 1.0063 0.0198 1.0063 0.0154
PACIFIC 69.00kV 1.0016 1.001 -0.0594 1.0015 -0.0056 1.0019 0.0316 1.0017 0.0168
SW7 69.00kV 1.0026 1.0018 -0.0763 1.0025 -0.0059 1.003 0.0425 1.0028 0.0223
QUECHAN 69.00kV 1.0002 0.9996 -0.0593 1.0001 -0.0095 1.0005 0.026 1.0004 0.0145
WALDRIP 69.00kV 1.0058 1.0047 -0.1027 1.0054 -0.0348 1.006 0.0188 1.0059 0.0145
SANLUIS 69.00kV 0.9916 0.9907 -0.0878 0.9913 -0.0283 0.9918 0.0182 0.9917 0.0133
Q217 System Impact Study APS Contract No.52588
Page 27
2014 Heavy Summer Case w//2016 configuration, High Yuma Load/Gen, TS8 project, Q43 full output
Results of the voltage flicker analysis indicate that there are no deviations greater than 1.5%. Table 3.18
details the results of the voltage flicker analysis. The greatest flicker is observed at the Foothills 69.0 kV
bus with a 0.2151% decrease with Q217. This occurs as the unit(s) adjusts from 100% to 10% output.
Table 3.18 Voltage Flicker Results, Q217
100% Generation (base) 10% Generation 30% Generation 60% Generation 90% Generation
Bus Voltage
(pu) Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation Voltage
(pu) Deviation
FOOTHILS 69.00kV 1.0112 1.009 -0.2151 1.0105 -0.0705 1.0116 0.043 1.0115 0.032
N.GILA 69.00kV 1.019 1.0182 -0.0781 1.019 -0.0025 1.0195 0.0485 1.0192 0.0249
REDONDO 69.00kV 1.0051 1.0042 -0.0903 1.005 -0.008 1.0056 0.0489 1.0054 0.0258
MITTRY 69.00kV 1.0146 1.0138 -0.0807 1.0146 -0.0044 1.0151 0.0475 1.0149 0.0246
ARABY S 69.00kV 1.0091 1.0078 -0.1332 1.0088 -0.0341 1.0095 0.0402 1.0094 0.0253
MAB S 69.00kV 1.0073 1.0061 -0.1192 1.0069 -0.0415 1.0075 0.0202 1.0074 0.0162
SANGUINE 69.00kV 1.005 1.0042 -0.0836 1.0049 -0.007 1.0055 0.0458 1.0052 0.0241
GILA 69.00kV 1.0118 1.011 -0.0805 1.0118 -0.0037 1.0123 0.0484 1.0121 0.025
SONEILL 69.00kV 1.0051 1.004 -0.1119 1.0047 -0.0387 1.0053 0.0193 1.0053 0.0153
PACIFIC 69.00kV 1.0007 1.0001 -0.0602 1.0007 -0.006 1.0011 0.0315 1.0009 0.0168
SW7 69.00kV 1.0016 1.0008 -0.0774 1.0015 -0.0065 1.002 0.0423 1.0018 0.0223
QUECHAN 69.00kV 0.9995 0.9989 -0.0598 0.9994 -0.0097 0.9998 0.026 0.9996 0.0145
WALDRIP 69.00kV 1.0048 1.0037 -0.1043 1.0044 -0.0359 1.005 0.0183 1.0049 0.0145
SANLUIS 69.00kV 0.9908 0.9899 -0.0884 0.9905 -0.0286 0.9909 0.0181 0.9909 0.0133
LAGUNA 69.00kV 1.0198 1.0192 -0.0608 1.0197 -0.0165 1.02 0.0169 1.0199 0.0109
FOOTHILS 69.00kV 1.0112 1.009 -0.2151 1.0105 -0.0705 1.0116 0.043 1.0115 0.032
N.GILA 69.00kV 1.019 1.0182 -0.0781 1.019 -0.0025 1.0195 0.0485 1.0192 0.0249
REDONDO 69.00kV 1.0051 1.0042 -0.0903 1.005 -0.008 1.0056 0.0489 1.0054 0.0258
MITTRY 69.00kV 1.0146 1.0138 -0.0807 1.0146 -0.0044 1.0151 0.0475 1.0149 0.0246
ARABY S 69.00kV 1.0091 1.0078 -0.1332 1.0088 -0.0341 1.0095 0.0402 1.0094 0.0253
MAB S 69.00kV 1.0073 1.0061 -0.1192 1.0069 -0.0415 1.0075 0.0202 1.0074 0.0162
SANGUINE 69.00kV 1.005 1.0042 -0.0836 1.0049 -0.007 1.0055 0.0458 1.0052 0.0241
GILA 69.00kV 1.0118 1.011 -0.0805 1.0118 -0.0037 1.0123 0.0484 1.0121 0.025
SONEILL 69.00kV 1.0051 1.004 -0.1119 1.0047 -0.0387 1.0053 0.0193 1.0053 0.0153
PACIFIC 69.00kV 1.0007 1.0001 -0.0602 1.0007 -0.006 1.0011 0.0315 1.0009 0.0168
SW7 69.00kV 1.0016 1.0008 -0.0774 1.0015 -0.0065 1.002 0.0423 1.0018 0.0223
QUECHAN 69.00kV 0.9995 0.9989 -0.0598 0.9994 -0.0097 0.9998 0.026 0.9996 0.0145
WALDRIP 69.00kV 1.0048 1.0037 -0.1043 1.0044 -0.0359 1.005 0.0183 1.0049 0.0145
SANLUIS 69.00kV 0.9908 0.9899 -0.0884 0.9905 -0.0286 0.9909 0.0181 0.9909 0.0133
3.4 Transient Stability Analysis
Sixty-Seven (67) outages were selected for transient stability evaluation. As referenced in the Reliability
Criteria section of this report, the system should meet the following transient stability performance criteria
for a NERC/WECC Category ‘B’ disturbance (N-1):
Transient voltage dip should not be below 25% at any load busses or 30% at any non-load busses at
any time.
The duration of a transient voltage dip greater than 20% should not exceed 20 cycles at load busses.
The minimum transient frequency should not fall below 59.6 Hz for more than 6 cycles at load
busses.
Appendix D contains transient stability plots of selected contingencies that provide a representative
illustration of the transmission system’s Post-Project voltage response.
Results indicate that there are no transient stability violations in the pre- or post-project cases.
Q217 System Impact Study APS Contract No.52588
Page 28
3.5 Short Circuit / Fault Duty Analysis Short circuit analysis of the proposed generator was performed by the APS Protection Department, using
the CAPE program and parameters supplied by the Applicant. Fault duties were calculated for both
single-phase –to-ground and three-phase faults at substation busses in the immediate surrounding area
before and after the proposed generator installation. The model also included the 2016 system
representation which included the Hassayampa-North Gila 500kv line, the North Gila-Orchard 230kv
project and some local 69kv planned upgrades. The results presented here assume a “worst-case”
scenario. The interconnection of the Q217 project does not cause any existing substation breakers to
exceed their rating. Table 3.19 Summarizes the results of the Short-Circuit analysis
Table 3.19 Short Circuit Results
Station Base Case With Q217 Min. Brkr
Rating -kA 3 Ph. (kA) X/R
Ph-G (kA) X/R
3 Ph. (kA) X/R
Ph-G (kA) X/R
Desert Sands 69kv 8.1 5.2 5.3 4.6 8.7 5.4 7.3 5.8 40
Gila 69kv 15.9 7.4 14.3 7.6 16.0 7.4 14.5 7.6 N/A
North Gila 69kv 19.8 9.3 22.5 10.5 20.1 9.4 22.9 10.5 31.5
3.6 Results & Findings Summary The results of the SIS indicate that the addition of Q217 results in no new post-project reliability violations
nor aggravation of pre-existing violations. However, the project as designed is not able to meet the power
factor requirements at this time. An additional 5.5 Mvar reactive support is necessary to compensate for
losses from the generators to the POI.
4 Cost & Construction Time Estimates
The cost estimates represent good faith estimates necessary to interconnect to the system. Not included
in these estimates are the additional reactive needs of the project, nor any costs associated with the
generator tie line after it leaves the new double circuited part. The non-binding, good faith cost and time
estimates are tabulated below. There are Right of Way and line construction costs associated with the
facilities APS is responsible to construct. Acquiring the Right of Way from the State of Arizona is
estimated to be the longest lead time for the project. Up to two miles of an existing APS 69kv line will
need to be rebuilt as double circuit 69kv which will require additional Right of Way. The substation costs
will consist of both Network Upgrades and Transmission Providers Interconnection Facilities.
Table 4
Q217 Estimates
Equipment Description Design
Time
(MO.)
Construction
Time
(MO.)
Network
Upgrades
($000)
Transmission
Providers
Interconnection
Facilities
($000)
Desert Sands: 69kV Switchyard Upgrades 3 3 127 145
Line Right of Way 18-24 N/A 0 70
Line Construction (double circuit 69kv-2 miles) 3 2 0 917
Totals 18-24 3 127 1132
Total Cost = $1,259,000
Q217 System Impact Study APS Contract No.52588
Page 29
Q217 System Impact Study APS Contract No.52588
Page 30
List of Acronyms
ACC Arizona Corporation Commission
ACSS Aluminum Conductor Steel Supported
ANPP Arizona Nuclear Power Project
APS Arizona Public Service
ATC Available Transfer Capability
CAISO California Independent System Operator Corporation
CAWCD Central Arizona Water Conservation District
CCVT Coupling Capacitor Voltage Transformer
COD Commercial Operation Date
CSP Concentrated Solar Power
CT Combustion Turbine or Current Transformer
EPE El Paso Electric
ER Energy Resource
ERIS Energy Resource Interconnection Service
FaS Facilities Study
FERC Federal Energy Regulatory Commission
FeS Feasibility Study
GT Gas Turbine
IC Interconnection Customer
IID Imperial Irrigation District
IR Interconnection Request
LADWP Los Angeles Department of Water and Power
LGIA Large Generator Interconnection Agreement
NEC Navopache Electric Cooperative
NERC North American Electric Reliability Corporation
NR Network Resource
NRIS Network Resource Interconnection Service
NTUA Navajo Tribal Utility Authority
OASIS Open Access Same Time Information System
OATT Open Access Transmission Tariff
PG&E Pacific Gas & Electric
PNM Public Service Company of New Mexico
POI Point Of Interconnection
PPA Purchase Power Agreement
PSLF/PSDS/SCSC Positive Sequence Load Flow/Positive Sequence Dynamic
Simulation/Short-Circuit Saturation Curve
PST Phase-Shifting Transformer
PV Photovoltaic
RAS Remedial Action Scheme (also known as SPS)
RFP Request for Proposal
Q217 System Impact Study APS Contract No.52588
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SCE Southern California Edison Company
SDG&E San Diego Gas & Electric Company
SIS System Impact Study
SLG fault Single Line-to-Ground fault
SPS Special Protection System (also known as RAS)
SRP Salt River Project
SSVEC Sulphur Springs Valley Electric Cooperative, Inc.
SVC Static VAR Compensator
SVD Static VAR Device
SWTC Southwest Transmission Cooperative
TEP Tucson Electric Power
TPIF Transmission Provider’s Interconnection Facilities
WAPA Western Area Power Administration
WECC Western Electricity Coordinating Council