ABB Inc.
Public Service Company of New Mexico
Broadview Full Buildout Affected PSLF Study
Final Report
ABB Power Systems Consulting
June 27, 2016
LEGAL NOTICE
This document, prepared by ABB Inc, is an account of work sponsored by Public Service
Company of New Mexico (PNM). Neither PNM nor ABB Inc. nor any person or persons acting
on behalf of either party: (i) makes any warranty or representation, expressed or implied, with
respect to the use of any information contained in this report, or that the use of any
information, apparatus, method, or process disclosed in this report may not infringe privately
owned rights, or (ii) assumes any liabilities with respect to the use of or for damages resulting
from the use of any information, apparatus, method, or process disclosed in this document.
Prepared for:
Report No.:
Date:
Public Service of New Mexico (PNM)
E00017436A-R01
June 27, 2016
Power Systems Consulting
Technical Report
ABB Inc.
E00017436A-R01
Public Service Company of New Mexico
Dept.
Broadview Full Buildout Affected PSLF Consulting
Study
Date
June 27, 2016
Pages
714
Executive Summary:
PNM has requested that ABB perform power flow and stability technical studies to increase
the power injections on the BA-Blackwater 345 kV line (BB line) to the maximum level of
1000 MW. Previous technical studies of 832 MW power injection on the BB line have
shown that a Static VAR Compensator (SVC) at the Guadalupe 345 kV station is necessary
to provide the required voltage support to accommodate these power transfers. The 1000
MW BB line power injections requested by PNM for this study are:




El Cabo wind farm at Clines Corner: 213 MW
Broadview wind farm: 497 MW
Taiban Mesa: 200 MW
Aragonne Mesa: 90 MW
This study includes the Guadalupe SVC rated 250 MVAr capacitive to 100 MVAr inductive.
The goal of this study is to determine if additional voltage support is required beyond the
planned Guadalupe SVC for the 1000 MW full buildout power injection. Several study tasks
were performed to assess the system impact of the extra power injections on the BB line.
The conclusions from the study tasks were as follows:




Powerflow contingency analysis on the study base case shows that, for the
analyzed contingencies, no substantial voltage/thermal violations occurred on the
BB line. Acceptable North American Electric Reliability Corporation (NERC)
Transmission Planning (TPL) performance is achieved without additional reactive
power support.
Voltage stability margin analysis (QV analysis) on the study base case and two
stress cases demonstrated that, for the analyzed contingencies, positive reactive
margin is maintained at Guadalupe. As such, the BB line transfers meet the WECC
voltage stability margin criteria.
Dynamic simulation on the study base case with selected N-1 and N-2
contingencies shows that, for all studied disturbances, adequate system dynamic
performance and adequate post-fault voltage recoveries are achieved. All wind
power plants on the BB line are able to ride-through the studied faults.
Dynamic simulation of selected N-1 contingencies on a sensitivity case with
Blackwater HVDC in service at 15 MW East-to-West showed stable performance.
The BB line wind power plants and the Blackwater HVDC are able to ride-through
the studied faults
The technical studies thus did not identify a need for additional voltage support beyond the
Guadalupe SVC for the 1000 MW full buildout scenario. The system was found to meet the
NERC TPL criteria and the WECC voltage stability margin criteria. All the wind farms on the
ii
BB line were found able to ride through the studied faults with adequate post-fault voltage
recoveries.
However, the limitations of the positive sequence models used in this study cannot
guarantee that a synchronous condenser at Blackwater station is not required to insure
sufficient short circuit capacity in the full buildout scenario for inverter based generation1.
PSCAD studies (3-phase model) are being performed in a separate study to evaluate
whether a synchronous condenser at Blackwater station will be required to support the
power injection conditions as stated above.
Rev #
Revision
Date
Author
Reviewed
1
PNM Comments
June 27, 2016
Huimin Li
D Dickmander
DISTRIBUTION Public Service New Mexico
1
WECC White Paper: Value and Limitations of the Positive Sequence Generic Models of Renewable
Energy Systems
https://www.wecc.biz/_layouts/15/WopiFrame.aspx?sourcedoc=/Administrative/White%20Paper%20Ge
neric%20Model%20Limitations%20December%202015.docx&action=default&DefaultItemOpen=1
iii
TABLE OF CONTENTS
1
Introduction.......................................................................................................................... 5
2
PSLF Model Setup .............................................................................................................. 7
3
4
2.1
STARTING CASE CONDITIONS ........................................................................................... 7
2.2
STUDY CASE SETUP (TASK1A) ......................................................................................... 9
2.2.1
Broadview Wind Farm Setup ................................................................................. 15
2.2.2
El Cabo Wind Farm Setup ..................................................................................... 16
2.2.3
Guadalupe SVC Setup........................................................................................... 17
2.2.4
Blackwater HVDC Setup ........................................................................................ 19
Power Flow Analysis ..........................................................................................................20
3.1
CONTINGENCY ANALYSIS (TASK 1B) ................................................................................ 20
3.2
QV ANALYSIS (TASK 1C) ................................................................................................ 22
3.2.1
QV Analysis Assumptions ...................................................................................... 22
3.2.2
QV Analysis Results .............................................................................................. 23
3.2.3
Guadalupe SVC Headroom ................................................................................... 26
3.2.4
QV Analysis Conclusions ....................................................................................... 26
Dynamic Simulations ..........................................................................................................27
4.1
DYNAMIC SIMULATION CONFIGURATIONS AND CASE LIST ................................................. 27
4.2
DYNAMIC SIMULATIONS WITH NOMINAL BB LINE LOAD ANALYSIS (TASK 1D) ...................... 28
4.3
SENSITIVITY CASE DYNAMIC ANALYSIS (TASK 1E) ............................................................ 28
5
Conclusions and Recommendations...................................................................................30
6
References .........................................................................................................................33
7
Appendices.........................................................................................................................34
APPENDIX A. CONTINGENCY ANALYSIS RESULTS, NOMINAL LOAD ON BB LINE ............................. 34
APPENDIX B. DYNAMIC SIMULATION PLOTS ............................................................................... 34
APPENDIX C. SENSITIVITY DYNAMIC SIMULATION RESULTS ........................................................ 34
4
1 Introduction
PNM has requested that ABB perform power flow and stability technical studies to increase the
power injections on the BA-Blackwater 345 kV line (BB line) to the maximum level of 1000
MW. Previous technical studies of 832 MW power injection on the BB line have shown that a
Static VAR Compensator (SVC) at the Guadalupe 345 kV station is necessary to provide the
required voltage support to accommodate these power transfers. The models and databases
for the recently completed studies serve as the starting point for adding the additional wind
resources included in the full buildout scenario. The goal of this study is to determine if
additional voltage support is required beyond the planned Guadalupe SVC for the power
injection assumptions in Figure 1-1 on PNM’s 216-mile, 345 kV transmission path between
Blackwater station and the BA station north of Bernalillo, New Mexico.
El Cabo 34.5 kV Bus
34.5kV/345 kV transformer
El Cabo 345 kV Bus 2
Tiaban Mesa 200 MW
Type 3
GE Wind Turbines
svc
6 Miles
54 Miles
Broadview 34.5 kV Bus
34.5 kV/345 kV transformer
Broadview 345 kV Bus
44 miles
+250/-100 MVAR
34 miles
Black Water 345 kV
Norton 345 kV bus
El Cabo 345 kV
To San Juan
Rio Puerco 345 kV
To Four Corners
Broadview 497 MW Wind
Type 4 Siemens Wind
Turbines
Iberdrola El Cabo 213 MW Wind
Type 3 Gamesha Wind Turbines
31 Miles
Taiban Mesa
345 kV
Aragonne 138/345 kV
transformer
70 Miles
62 Miles
Aragonne 138 kV Bus 4
Blackwater
Converter
20.38 miles
To West Mesa
BA 345 kV
Guadalupe 345
To 115 kV
System
Aragonne 138 kV Bus 3
Aragonne 34.5kV/138 kV transformer
Aragonne 34.5 kV Bus 2
DSTATCOM
Aragonne Mesa
90 MW
Type 1
Mitshubishi Wind Turbines
Existing Transmission System
Interconnection Customer Faclities
Figure 1-1: Study Configuration on the Blackwater-BA 345kV Line
5
The study steps requested by PNM are outlined below in Table 1-1.
Table 1-1: Study Task Outline
Study case set up
Powerflow study
Dynamic study
Task #
1a
1b
1c
1d
1e
Task description
Configure base cases
Contingency analysis on the base case without stress conditions
QV analysis on the base case without and with stress conditions
Dynamic simulation on the base case
Sensitivity case with Blackwater at 15 MW E-W
This report is arranged as follows to address each of the above tasks:
1. All cases including the starting case, the study base case without/with stress conditions
and the sensitivity case are defined in Section 2.
2. Powerflow studies are described in Section 3 as follows:
a. In Section 3.1, powerflow contingency studies of the base case, without stress
conditions, are performed to determine if contingency performance meets
steady state North American Electric Reliability Corporation (NERC)
Transmission Planning (TPL) criteria. The focus of the analysis is limited to
defining adequate voltage support between BA and Blackwater for the full
buildout conditions, and identify overloads or voltage violations. Addressing
overloads or voltage violations west of BA is outside the scope of this analysis.
b. In Section 3.2, QV analysis is performed on the base case with and without
stress conditions to confirm that transfers meet WECC voltage stability margin
criteria.
3. Dynamic studies are described in Section 4 as follows:
a. In Section 4.1, system configurations and case lists are described.
b. In Section 4.2, dynamic simulations are performed on the base case without
stress conditions.
c. In Section 4.3, dynamic simulations are performed on the sensitivity case with
Blackwater in service at 15 MW E-W.
4. Conclusions and recommendations of this study are presented in Section 5.
5. Section 6 and Section 7 list the references and the appendices of the study.
6
2 PSLF Model Setup
2.1 Starting Case Conditions
This section describes development of based cases from the starting PSLF model from the
Broadview study. The starting PSLF model that formed the basis for the studies was the base
case developed for prior studies. The system data from PNM were provided in PSLF version
18 format.
The following PNM equipment is included in the starting case:


Broadview Generation Injection at Blackwater 345 kV: 297 MW
Blackwater HVDC: 75 MW E-W


Taiban Mesa: 200 MW
Aragonne Mesa: 90 MW
A total of 662 MW is injected on the BB line in the starting case as shown in Figure 21.
7
Figure 2-1: One-Line for the 297 MW Broadview Case (Input to Present Study)
8
2.2 Study Case Setup (Task1a)
Starting from the powerflow case presented in Section 2.1, the modifications listed below were
made to develop the base case of the full buildout scenario.

Add the 200 MW Grady wind farm at Broadview

Add the 213 MW El Cabo wind farm at Clines Corner


Add the 250/-100 MVAr SVC in service at Guadalupe.
Disconnect the HVDC converter at Blackwater
The resulting PSLF model developed as the base case for this study shown in Figure 2-2. The
case was developed in PSLF version 18 format. In addition to the base case, two stress cases
and one sensitivity case were developed, as shown in Figure 2-3 to Figure 2-5:


The two stress cases are only for checking the WECC voltage stability margin criteria.
The cases are setup by adding stress conditions on the base case. The defined stress
conditions include:
o Stress condition 1: Increasing each power injection on the BB line by 5.25%
(5% stress case)
o Stress condition 2: Increasing each power injection on the BB line by 2.56%
(2.5% stress case).
The sensitivity case is for checking the BB line fault recovery ability with Blackwater
HVDC operates at its minimum power level E-W. The case is set up with Blackwater
HVDC in service at 15 MW east to west, and with a reduced power level of the
Broadview wind farm to keep the total BB line injections the same as the base case.
A total of four cases were thus set up for this study to capture the above conditions. All case
conditions are summarized in Table 2-1.
9
Figure 2-2: One-Line for the Study Base Case
10
Figure 2-3: One-Line for the 5% Stress Case
11
Figure 2-4: One-Line for the 2.5% Stress Case
12
Figure 2-5: One-Line for the Sensitivity Case
13
Table 2-1: Study Case Conditions
EI Cabo 5
EI Cabo 5-1
AM
TM
Grady , GWECMV1 Grady , GWECMV2
BEJN1
BEJN2
BEKW
BLW HVDC E-W Guad SVC RioP SVC Total BB
Case
Status WTG [MW] Status WTG [MW] Status WTG [MW] Status WTG [MW] Status WTG [MW] Status WTG [MW] Status WTG [MW] Status WTG [MW] Status WTG [MW] Status P [MW] Status
Status line MW Usage
Starting Case NA
0
NA
0
IN
94
IN
206
NA
0
NA
0
IN
88
IN
89
IN
125
IN
75
OUT
IN
677
Task 1a
Task 1b,
Base Case
IN
107
IN
94
IN
206
IN
100
IN
100
IN
88
IN
89
IN
125
OUT
0
IN
IN
1020
1c and 1d
111
IN
Stress Case 1 IN
116.8275
IN
112.6175
IN
98.935
IN
216.815
IN
105.25
IN
105.25
IN
92.62
IN
93.6725
IN
131.5625 OUT
0
IN
IN
1073.55 Task 1c
Stress Case 2 IN
113.8416
IN
109.7392
IN
96.4064
IN
211.2736
IN
102.56
IN
102.56
IN
90.2528
IN
91.2784
IN
128.2
OUT
0
IN
IN
1046.112 Task 1c
Sensitivity
IN
107
IN
94
IN
206
IN
92.5
IN
92.5
IN
88
IN
89
IN
125
IN
15
IN
IN
1020
Task 1e
Case
111
IN
Notes:

NA: not applicable to this case

Starting case: Case from PNM Broadview PSLF study (662 MW injections on BB line).

Base case: the full buildout scenario with 1000 MW injections on the BB line.

Stress case 1: Base case with 5.25% increase on the total BB line MW injection.

Stress case 2: Base case with 2.56% increase on the total BB line MW injection.

Sensitivity case: Base case with Blackwater HVDC in service at 15 MW E-W schedule, and a 15MW power reduction at the Broadview wind farm. The
total BB line injections are thus the same as the base case.

Descriptions on each of the tasks are in Table 1-1.
14
2.2.1 Broadview Wind Farm Setup
The Broadview/Grady wind farm includes five sections: “BEJN1”, “BEJN2”, “BEKW”,
“GWECMV1” and “GWECMV2”. Type 4 wind turbines are assumed for all five sections.
Detailed models of the Broadview wind farm were provided by PNM including:


The wind farm collector system
Wind turbine generator dynamic models based on the PSLF regc_a, reec_a, and
wtgt_a models.
The power flow model of each section of the Broadview wind farm is represented by aggregate
models. The parameters used for the PSLF models are listed in Table 2-2.
Table 2-2: Broadview Wind Farm PSLF Powerflow Model Parameters
Parameter
BEJN1
BEJN2
BEKW
GWECMV1
GWECMV2
WTG Pgen [MW]
88
89
125
100
100
Turbine GSU transformer
MVA
Wind farm main transformer
F/T winding kV
Turbine GSU transformer R1
[pu]
Turbine GSU transformer X1
[pu]
Wind farm main transformer
MVA
Wind farm main transformer
H/X winding kV
Wind farm main transformer
34.5/345 kV R1 [pu]
Wind farm main transformer
34.5/345 kV X1 [pu]
Collector System Voltage
[kV]
Collector System R1 [pu] [a]
100
100
100
100
100
34.5/0.69
34.5/0.69
34.5/0.69
34.5/0.69
34.5/0.69
0.00551
0.005373
0.003466
0.00463
0.00463
0.055105
0.053727
0.034663
0.04630
0.04630
60.0
60.0
90.0
100.0
100.0
358.8/34.5
358.8/34.5
358.8/34.5
358.8/34.5
358.8/34.5
0.002117
0.002117
0.002100
0.002490
0.002490
0.080000
0.080000
0.080000
0.106400
0.106400
34.5
34.5
34.5
34.5
34.5
0.010450
0.013140
0.005470
0.008536
0.007824
Collector System X1 [pu]
0.011530
0.015950
0.006010
0.008759
0.007652
Collector System B1 [pu]
0.058890
0.075580
0.076340
0.055828
0.049345
345 kV Line to BV_POI_3-T~1
[b]
R1 [pu]
345 kV Line to BV_POI_3-T~1
X1 [pu]
345 kV Line to BV_POI_3-T~1
B1 [pu]
0.000268
0
0.000380
0.002631
0
0.003527
0.044819
0
0.064800
Note
Siemens SWT 2.3 VS
Aggregate 497 MW
Aggregate
Grady data: reference
[2] & [3]
Other data: Broadview
PSCAD study
Grady data: reference
[2] & [3]
Other data: Broadview
PSCAD study
Grady data: reference
[2] & [3]
Other data: Broadview
PSCAD study
BEKW’s high station is
Broadview POI
Notes:
[a] Impedance is on the system 100 MVA base.
[b] The 345 kV lines referenced above are the three transmission lines between the grouped
wind farm sections and the wind farm main 345 kV collector bus (BV_POI_3-T~1). Impedance is
on the system 100 MVA base.
15
2.2.2 El Cabo Wind Farm Setup
The El Cabo wind farm includes two sections. All wind turbines are Type 3 machines. A
detailed model of the El Cabo wind farm was supplied by PNM including:


The wind farm collector system
Wind turbine generator dynamic models based on the PSLF wt3g, wt3e, and wt3t
models.
The power flow model of each wind farm section is represented by aggregate models. The
parameters used for the PSLF models are listed in Table 2-3.
Table 2-3: El Cabo Wind Farm PSLF Powerflow Model Parameters
Parameter
ELCABO 5
ELCABO 5_1
Note
WTG Pgen [MW]
Turbine GSU transformer
MVA
Wind farm main transformer
F/T winding kV
Turbine GSU transformer R1
[pu]
Turbine GSU transformer X1
[pu]
Wind farm main transformer
MVA
Wind farm main transformer
H/X winding kV
Wind farm main transformer
34.5/345 kV R1 [pu]
Wind farm main transformer
34.5/345 kV X1 [pu]
Collector System Voltage
[kV]
Collector System R1 [pu] [a]
111
107
Aggregate 213 MW at POI
100
100
Aggregate
34.5/0.69
34.5/0.69
0.005724
0.005961
0.064697
0.067355
100.0
100.0
345/34.5
345/34.5
0.002143
0.002143
0.101420
0.101420
34.5
34.5
0.010777
0.010732
Collector System X1 [pu]
0.067959
0.065480
Collector System B 1[pu]
345 kV Line ELCABO2 –
ELCABO1 [a] R1 [pu]
345 kV Line ELCABO2 –
ELCABO1 X1 [pu]
345 kV Line ELCABO2 –
ELCABO1 B1 [pu]
0.036933
0.034280
Reference [4]
0.001010
0.014340
0.257840
Note:
[a] Impedance is based on the system 100 MVA base.
16
Reference [5]
2.2.3 Guadalupe SVC Setup
The Guadalupe SVC is being designed as a duplicate of the Rio Puerco SVC except for the
filter bank configuration which will include 5th and 7th harmonic filters as compared to the two
fifth harmonic filters used at Rio Puerco. The total filter reactive capability will remain at 75
MVAr as with Rio Puerco SVC. For this analysis, the Guadalupe SVC is assumed to comprise
the following components:


One Thyristor Controlled Reactor (TCR) rated 175 MVAr.
One Thyristor Switched Capactor (TSC) rated 175 MVAr.

5th and 7th harmonic filters, totaling 75 MVAr.
The maximum capacitive output is attained with the TSCs switched on and the TCR at a zero
conduction angle. This results in an admittance of 250 MVAr (including filters) at the SVC
terminal bus. The rated inductive output, on the other hand, is attained with the TCR at full
absorption and the TSCs switched out, and amounts to an admittance of 100 MVAr (including
filters).
Rio Puerco SVC controls two Mechanical Switched Capacitors (MSCs) and one Mechanical
Switched Reactor (MSR). In this study, it is assumed that there is no MSR and MSC controlled
by the Guadalupe SVC.
In the power flow, the SVC is represented as a Type 5 Static VAr Device (SVD) with ID “v1”
and modeled on the high voltage side of the SVC's 345 kV terminal bus since the modeled
controls are based on high voltage side measurements. See Figure 2-6 for the network
adjacent to Guadalupe. The SVC is connected to the Guadalupe 345 kV station.
For the dynamic simulation, the Guadalupe SVC model is converted to a generator model with
ID “g1” to interface to the user defined control algorithms. An epcl file
“PrepForDyd_Guad_SVC.p” is modified from the similar Rio Puerco version to accomplish this
conversion.
Control strategies of the Guadalupe SVC are similar to those for Rio Puerco SVC, Reference
[6], except that Guadalupe SVC does not need to control external mechanically switched
banks.
Step response tests for the Guadalupe SVC are presented in Section 4. As comparison step
response of the Rio Puerco SVC is also presented.
17
Figure 2-6: Power Flow Data for Guadalupe SVC
18
2.2.4 Blackwater HVDC Setup
This section only applies to the sensitivity case.
Based on Reference [7], an epcl file previously developed by ABB was used to automatically
configure the Blackwater filters and transformer taps for the scheduled HVDC power level. In
the sensitivity case, the Blackwater HVDC scheduled power level is set at 15 MW E-W. As
such, the PNM station is operated as an inverter. For operation at 15 MW, the Blackwater DC
voltage is reduced from the nominal 57 kV to around 13 kV as shown in Table 2-4:
Table 2-4: Blackwater HVDC PSLF Powerflow Model Parameters
Parameters
SPS Station
PNM Station
p_sched [MW]
Settings/Values
15.5
Settings/Values
-14.6
DC voltage [kV]
13.0
13.0
DC Current [kA]
1550.0
1550.0
AC Filters
2X 26.5 MVAr
3X 26.5 MVAr
The resulting powerflow at Blackwater is shown in Figure 2-7.
Figure 2-7: Power Flow Data for Blackwater HVDC in Sensitivity Study
19
3 Power Flow Analysis
3.1
Contingency Analysis (Task 1b)
Contingency analysis was performed on the base case shown in Table 2-1 to confirm that
steady state TPL performance criteria are met. The studied contingencies are in Table 3-1:
Table 3-1: Contingency List
Contingency Name
Contingency Description
Base
N-0
System Intact
BA-RP
N-1
BA-Rio Puerco 345 kV
BA345/115 TX
N-1
BA 345/115 kV Transformer
BA-NR
N-1
BA to Norton 345 kV
RP-WM
N-1
Rio Puerco–West Mesa 345 kV
RP-SJ
N-1
Rio Puerco–San Juan 345 kV
RP-FC
N-1
BAHBALRP
N-2
RPWMHL2
N-2
BA-RP-N2
N-2
Rio Puerco–Four Corners 345 kV
BA 345/115 kV Transformer and BA–Rio Puerco 345 kV
Line
Rio Puerco-West Mesa & West Mesa 345/115 kV
Transformer
BA-Rio Puerco 345 kV Double-Circuit Outage
The PNM-specific voltage and thermal criteria are listed in Table 3-2:
Table 3-2: PNM Voltage and Thermal Criteria
Area
Conditions
Normal
Loading Limits
< Normal Rating
EPEC
(Area 11)
PNM
(Area 10)
Tri- State
(zones
120-123)
Contingency
< Emergency Rating
Normal ALIS
< Normal Rating
Contingency N-1
< Emergency Rating
Contingency N-2
Normal ALIS
< Emergency Rating
< Normal Rating
Contingency N-1
< Emergency Rating
Contingency N-2
< Emergency Rating
Voltage (p.u.)
Voltage
Drop
Application
0.95 - 1.05
0.95 - 1.10
69kV and above
Artesia 345 kV
0.95 - 1.08
Arroyo 345 kV PST source side
0.90 - 1.05
0.925 - 1.05
0.95 - 1.07
0.95 - 1.08
0.90 - 1.05
0.95 - 1.05
0.95-1.05
0.925-1.08**
6%
Alamo, Sierra Blanca and Van Horn 69kV
60 kV to 115 kV
Artesia 345kV
Arroyo 345kV PST source side
Alamo, Sierra Blanca and Van Horn 69kV
Hidalgo, Luna, or other 345 kV buses
46 kV and above*
46 kV to 115 kV
0.90 – 1.08**
6%
230 kV and above*
0.90-1.08**
0.95-1.05
10%
0.90-1.1
6%
0.90-1.1
7%
0.90-1.1
10%
7%
7%
7%
7%
46 kV and above*
All buses
69 kV and above except Northeastern NM
and Southern NM
69 kV and above in Northeastern NM and
Southern NM
All buses
*Taiban Mesa and Guadalupe 345 kV voltage range is 0.95 p.u. to 1.1 p.u. under normal and
contingency conditions.
** Provided operator action can be utilized to adjust voltages back down to 1.05
20
The contingency analysis is performed based on the following assumptions:

Powerflow contingency analysis focuses on the system condition immediately after the
contingency. Fast closed loop controls (FACTS, HVDC) are allowed to regulate, but
the mechanically switched devices such as switched capacitors and transformer taps
are locked post-contingency.

No head room of the Rio Puerco SVC was retained post-contingency. This means that
post-contingency output for both the Rio Puerco and Guadalupe SVCs is allowed to
move up to the maximum capability.
Two 48 MVAr shunts at “WESTMS_2 115” and “SANDIA_2 115” are switched in precontingency to help the system condition.
A total of 4X10 MVAr caps at the El Cabo wind farms are in service pre-contingency.
WTGs of El Cabo wind farms are close to their maximum reactive limit in precontingency.


Detailed results of the contingency analysis are presented in Appendix A. From the results, it is
noticed that:



Among all the contingencies, the highest post-contingency Guadalupe SVC
susceptance reference is 1.824 pu (1.0 pu Bref is 100 MVAr at nominal voltage), for the
double contingency of both BA-Rio Puerco 345 kV lines.
No low voltage violations were identified. Minor high voltage violations occur postcontingency at Broadview 345 kV buses. These high voltages are related to an initial
voltage of 1.056 pu at Broadview 345 kV from the Broadview PSCAD study. This was
a result of steady-state voltage and tap conditions from debugging efforts on the
Siemens wind turbine models during the Broadview PSCAD study. These violations
can be removed by very minor modification to the voltage profile if needed.
For the double contingency “BA-Rio Puerco 345 kV 1 & 2”:
o Overloads are identified on the BA 345/115 kV transformer and the 115 kV
systems near the BA 115 kV station. For this double contingency, the RP-BA
345 circuits are both open post-contingency, resulting in increased flow into the
115 kV system at BA.
o Overload is identified on the El Cabo to BA 345 KV line. This line is fully loaded
pre-contingency, with sight (2%) post-contingency overload.
Overall, it can be concluded from the contingency analysis that from the list of the analyzed
contingencies, no substantial violations occurred in the monitored areas and zones (Table 32). Thus an acceptable TPL performance is achieved.
21
3.2
QV Analysis (Task 1c)
3.2.1 QV Analysis Assumptions
Steady-state reactive margin analysis (Q-V analysis) was performed at the Guadalupe 345 kV
station using the GE-SSTOOLS scripts. For the Q-V analysis, the following assumptions are
made:

Reactive power injections are defined as the total Q at Guadalupe 345 kV station. This
means that the Guadalupe SVC output is taken into account while generating the QV
curves and the results.

AC voltage at the Q-V test points are varied up to 1.05 pu, using an infinite reactive
source at the test point.

QV curves are developed only for the Guadalupe 345 kV bus.


Rio Puerco SVC is modeled as a Type 5 SVD, and adjustable post-contingency.
Base case Q-V curves were developed for all contingencies in Table 3-1 except for
“BA-Rio Puerco 345 kV Double-Circuit Outage”.
Q-V curves for single contingencies (Table 3-1) were developed for the 5% stress case
(Stress case 1 in Table 2-1).
Q-V curves for all double contingencies (Table 3-1) except for “BA-Rio Puerco 345 kV
Double-Circuit Outage” were developed for the 2.5% stress case (Stress case 2 in
Table 2-1).
For the two stress cases, the Guadalupe SVC is connected pre-contingency and the
Guadalupe SVC is modeled as a generator with fixed Q.
4 X 10MVAr El Cabo wind farm shunt caps are in service (total is 10 X 10 MVAr).







All available Broadview wind farm shunt reactors (5 X 10MVAr) are in service.
The El Cabo wind farm model included for QV analysis is set to 213 MW at the POI.
The wind farm aggregate generator MVAr limits are set at the aggregate VAR capability
at 213 MW Pgen. This means that when the injection level is below the nominal level,
the effective power factor range is increased; when the injection level is above the
nominal level, the effective power factor range is decreased.
Similar to the El Cabo, the Broadview wind farm aggregate generator MVAr limits are
set at the aggregate VAR capability at 497 MW Pgen. WTG VAR capability was
provided by Siemens in the Broadview PSLF study. This means that when the injection
level is below the nominal level, the effective power factor range is increased; when the
injection level is above the nominal level, the effective power factor range is decreased.
Table 3-3 summarizes the QV analysis setup.
22
Table 3-3: QV Analysis Setup
QV Cases
Contingency
Number of QV Curves
Base Case
N-0, N-1 and N-2
9
Stress Case 1
N-0 and N-1
7
Stress Case 2
N-0 and N-2
3
3.2.2 QV Analysis Results
Results from QV analysis are presented below in the plots of Figures 3-1 through 3-5, and
summarized in Table 3-4 to Table 3-6. As illustrated in Figures 3-1 Figure 3-3, the slope of the
QV curves for all studied outages on the three system conditions indicates stable system
performance for Guadalupe 345 kV station voltages in the normal range of 0.95 pu to 1.05 pu.
With increased power injections on BB line, there is a significant decrease in the reactive
margin. With the N-0 condition of the three powerflow cases (Base, Stress 1, and Stress 2)
taken as an example, and when Guadalupe 345 kV station operates at 0.95 pu voltage:



The reserved reactive margin for base case without stress condition is ~92 MVAr1;
The reactive margin is decreased to ~67 MVAr1 if the BB line load is increased by
2.56% of the nominal level;
The reactive margin is further decreased to ~38 MVAr1 if BB line load is increased by
5.25% of the nominal level.
1
Note that remaining headroom on Guadalupe SVC can be added to these values (Section 3.2.3)
Figure 3-1: QV Curves at Nominal BB Line Load
23
Figure 3-2: QV Curves at 105.25% of Nominal Level
Figure 3-3: QV Curves at 102.56% of Nominal Level
24
Table 3-4 to Table 3-6 summarize the reactive margins of studied outages at different system
conditions.
Table 3-4: Summary of Guadalupe 345 kV Bus QV Analysis at Nominal BB Line Load
Configuration
N-0, N-1 &N-2 Outages
Minimum Reactive Margin
Reactive Power Requirements
MVAr[1]
Guad Voltage [pu]
RioP Bsvc[pu][2]
@V = 1.00 [pu]
@V = 1.04 [pu]
-130
0.91
1.97
-8.8
132
Nominal Load
No Outage
Nominal Load
BA-Rio Puerco 345 kV 1
-107.6
0.91
1.55
-1
134.3
Nominal Load
BA 345/115 kV 1
-124.4
0.91
2.22
-5
135.2
Nominal Load
BA-Norton 345 kV 1
-122.5
0.91
2.29
-2.9
137.5
Nominal Load
Rio Puerco-West Mesa 345 kV 2
-127.5
0.91
2.21
-6.4
134.5
Nominal Load
Rio Puerco-San Juan 345 kV 1
-126.9
0.91
2.25
-7.4
132.8
Nominal Load
Rio Puerco-Four Corners 345 kV
-126.4
0.91
2.29
-6.9
133.4
Nominal Load
1
BA-Rio Puerco 345 kV & BA
-95.3
0.91
1.86
6.7
140.3
-126.7
0.91
2.19
-5.7
135.2
345/115 kV
Nominal Load
Rio Puerco-West Mesa 345 kV &
West Mesa 345/115kV
Notes:
[1] A negative number indicates the presence of reactive power reserves while a positive
number indicates that reactive power support is required to obtain a stable solution.
[2] Q of Rio Puerco SVC at the point of Guadalupe minimum reactive margin (Guadalupe
Voltage = 0.91 pu in Table 3-4). Positive number means SVC is delivering VARs to the system.
[3] Above two footnotes also apply to Table 3-5 and 3-6.
[4] See also Section 3.2.3
Table 3-5: Summary of Guadalupe 345 kV Bus QV Analysis at 105.25% of Nominal BB Line Load
Configuration
N-0 & N-1 Outages
Minimum Reactive Margin
Reactive Power Requirements
MVAr
Guad Voltage[pu]
RioP Bsvc[pu]
@V = 1.00 pu
@V = 1.04 pu
5.25% Pre-Con Load Increase
No Outage
-57.2
0.925
1.86
36.7
159.3
5.25% Pre-Con Load Increase
BA-Rio Puerco 345
-35.5
0.925
1.46
46.1
162.4
5.25% Pre-Con Load Increase
kV 1
BA 345/115 kV 1
-50.7
0.925
2.11
41.9
163.7
5.25% Pre-Con Load Increase
BA-Norton 345 kV 1
-48.9
0.925
2.2
43.9
165.7
5.25% Pre-Con Load Increase
Rio Puerco-West
-54.6
0.925
2.09
39.3
161.9
-54.2
0.925
2.12
38.3
160.2
-53.7
0.925
2.16
38.9
160.8
Mesa 345 kV 2
5.25% Pre-Con Load Increase
Rio Puerco-San Juan
345 kV 1
5.25% Pre-Con Load Increase
Rio Puerco-Four
Corners 345 kV 1
25
Table 3-6: Summary of Guadalupe 345 kV Bus QV Analysis at 102.56% of Nominal BB Line Load
Configuration
2.56% Pre-Con
N-0 &N-2 Outages
No Outage
Minimum Reactive Margin
Reactive Power Requirements
MVAr
Guad Voltage [pu]
RioP Bsvc[pu]
@V = 1.00 pu
@V = 1.04 pu
-95
0.92
1.86
12.4
144.6
-60.1
0.92
1.77
29.9
154.6
-91.7
0.92
2.08
15.5
147.9
Load Increase
2.56% Pre-Con
BA-Rio Puerco 345 kV & BA
Load Increase
345/115 kV
2.56% Pre-Con
Rio Puerco-West Mesa 345
Load Increase
kV & West Mesa 345/115kV
3.2.3 Guadalupe SVC Headroom
As described earlier, the Guadalupe SVC output is taken into account while generating the QV
curves. Unused Guadalupe SVC capacitive VARs can thus be considered as additional
reactive reserves, adding to the reactive margin shown in the QV analysis results. The used
and remaining (unused) Guadalupe SVC capacitive VARs for each of the QV cases is
summarized in Table 3-7:
Table 3-7: QV Analysis: Headroom Remaining of Guadalupe SVC
QV Cases
SVC output (MVAr)
SVC Headroom Remaining (MVAr)
Base Case
0
250
Stress Case 1 (5.25%
increase)
103
147
Stress Case 2 (2.56%
increase)
85
165
3.2.4 QV Analysis Conclusions
Based on the QV analysis, the following conclusions can be made:

Positive reactive margin is seen at Guadalupe 345 kV for all studied contingencies.

With increased power injections on BB line, there is a significant decrease in the
reactive margin.
Pre-contingency VAR support is needed at Guadalupe 345 kV station for stress cases
to solve the power flow at high voltage such as 1.05 pu.


Rio Puerco SVC shows relatively high capacitive output when Guadalupe voltage is at
the low side, especially when the BB line load is at 105.25% of the nominal level.
26
4 Dynamic Simulations
4.1
Dynamic Simulation Configurations and Case List
After the power flow study in Section 3, dynamic cases were run for selected N-1 or N-2
contingencies to help ensure:

Adequate system dynamic performance and adequate post-fault voltage recovery.

That all the existing wind power plants on The BB line will ride-through the fault.
Dynamic simulations were performed on a list of contingencies as shown in Table 4-1:
Table 4-1. Dynamics Case List
Contingency
Name
Description
0
N-0
System intact, flat run
1
BA-RP
2
BA345/115 TX
4-Cycle 3ph fault on BA-RP close to BA 345 kV. Clear BA at 4 Cycles. Clear RP at 6
Cycles
4-Cycle 3ph fault at BA 345 kV, trip BA 345/115 kV Transformer at 4 cycles
3
BA-NR
4-Cycle 3ph fault at BA 345 kV, trip the BA- NR 345 kV line at the 4 cycles
4
RP-WM
4-Cycle 3ph fault at RP 345 kV, trip the RP-WM 345 kV line at the 4 cycles
5
RP-SJ
4-Cycle 3ph fault at RP 345 kV, trip the RP-SJ 345 kV line at the 4 cycles
6
RP-FC
4-Cycle 3ph fault at RP 345 kV, trip the RP-FC 345 kV line at the 4 cycles
7
GuadSvcTrp
Trip the Guadalupe SVC after 1 second flat run
8
BAHBALRP
9
RPWMHL2
10
BA-RP-N2
N-2: 3-Cycle 3ph fault on BA-RP close to BA 345 kV. Clear BA and RP at 4 Cycles.
Trip the BA345/115 kV Transformer at 4 cycles.
N-2: 3-Cycle 3ph fault on WW-RP close to West Mesa 345 kV. Clear WM and RP at 4
Cycles. Trip the WM 345/115 kV Transformer at 4 cycles.
N-2: 4-Cycle 3ph fault on BA-RP close to BA 345 kV. Clear BA & RP at 4 Cycles. Trip
the BA-RP double cks at 4 cycles.
The following assumptions are used for the dynamic simulations:


Dispatch as shown in Figure 1-1 (base case in Table 2-1).
The Broadview and El Cabo wind farms are represented using collector system models
and wind turbine models provided by PNM.
As it was mentioned in Section 2.2.3, a duplicate of the Rio Puerco SVC for Guadalupe SVC is
used for this study. Since the network strength at Guadalupe is different from Rio Puerco,
sensitivity testing on voltage regulator gains for Guadalupe was performed. Three gain settings
as listed in Table 4-2 were tested.
Table 4-2: Guadalupe SVC Gain Settings Tested
Guadalupe SVC Gain setting #
Kp
Ki
1
20
1300
2
6
500
3
6
250
27
The gains for Rio Puerco SVC are 6 and 2300 for the proportional and integral gain
respectively. As shown in Table 4-2:

For the test gain setting #1, the Guadalupe SVC uses higher Kp but lower Ki as
compared to the Rio Puerco SVC.

A reduced integral gain was tried in all settings (#1 #2 and #3) as compared to Rio
Puerco.
In this study, the dynamic simulations described in Section 4.2 and Section 4.3 were
performed with three Guadalupe SVC gain settings. It should be noted that the gains set in
PSLF study are preliminary, and detailed settings of the SVC gains will need to be confirmed
with PSCAD studies as part of the Guadalupe SVC project.
4.2
Dynamic Simulations with Nominal BB Line Load Analysis (Task 1d)
For the study base case shown in Figure 2-2, dynamic simulations were run for all
contingencies listed in Table 4-1. Three sets of plots corresponding to the three tested
Guadalupe SVC gains are available in Appendix B, as Appendices B-1, B-2, and B-3,
corresponding to the numberings given in Table 4-2. Step responses of Rio Puerco and
Guadalupe SVC are also included in the three parts of Appendix B.
The results show that for the base case of the full buildout scenario:

With nominal BB line dispatch plus a 250/-100 MVAr SVC at the Guadalupe 345 kV
station, system stability is maintained for all studied N-1 and all N-2 contingencies.

All the wind power plants on the BB line are able to ride-through the studied faults

For certain faults such as “BA-Rio Puerco, N-1” and “Rio Puerco – Four Corner, N-1”,
oscillations in the reactive power measured at the Guadalupe side of the Guadalupe
345 kV – Argonne 138 kV transformer was observed. Investigation of the oscillations
indicates that the oscillations originate within the Argonne Mesa wind farm and are not
related to the Guadalupe SVC.

Guadalupe SVC integral gain is recommended to be lowered to 10% - 20% comparing
to the Rio Puerco SVC gain settings. This is due to the weaker network strength at
Guadalupe 345 kV station.
4.3
Sensitivity Case Dynamic Analysis (Task 1e)
As shown in Table 2-1 and Figure 2-5, the sensitivity case was setup with Blackwater HVDC in
service with a 15 MW E-W schedule, which is the minimum power of the Blackwater HVDC.
The Broadview wind farm power level was also reduced by 15 MW to hold the total BB line
power injection the same as in the study base case.
28
Dynamic simulations were run on the N-0 and N-1 contingencies listed in Table 4-1. Three sets
of plots corresponding to the three tested Guadalupe SVC gains are available in Appendix C,
as Appendices C-1, C-2, and C-3, corresponding to the numberings given in Table 4-2. Step
responses of Rio Puerco and Guadalupe SVC are also included in the three parts of Appendix
C.
The results show that for the sensitivity case as dispatched in Figure 2-5:

System stability is maintained for all studied N-1 contingencies.

All the BB line wind power plants and the Blackwater HVDC are able to ride-through
the studied faults.

For certain faults such as “BA-Rio Puerco, N-1” and “Rio Puerco – Four Corner, N-1”,
the previously described oscillations in reactive power measured at the Guadalupe side
of the Guadalupe 345 kV – Argonne 138 kV transformer was observed. Again, these
oscillations originate within Aragonne Mesa and are unrelated to the SVC.

The sensitivity case resulted in similar conclusions regarding SVC gain: Guadalupe
SVC integral gain is recommended to be lowered to 10% - 20% comparing to the Rio
Puerco SVC gain settings due to the weaker network strength at Guadalupe 345 kV
station.
29
5 Conclusions and Recommendations
PNM requested ABB to perform power flow and stability technical studies to increase the
power injections on the BA-Blackwater 345 kV line (BB line) to the maximum level of 1000
MW. Previous technical studies of 832 MW power injection on the BB line have shown that a
Static VAR Compensator (SVC) at the Guadalupe 345 kV station is necessary to provide the
required voltage support to accommodate these power transfers. The 1000 MW BB line power
injections for this study are:




El Cabo wind farm at Clines Corner: 213 MW
Broadview wind farm: 497 MW
Taiban Mesa: 200 MW
Aragonne Mesa: 90 MW
The main conclusions from the study are as follows:
1. Powerflow contingency analysis showed that:

Among all the contingencies, the highest post-contingency Guadalupe SVC
susceptance reference is 1.824 pu (1.0 pu Bref is 100 MVAr at nominal voltage, the
post contingency Guadalupe voltage is about 1.019pu. As such, Qsvc is about 190
MVAr), for the double contingency of both BA-Rio Puerco 345 kV lines.
 No low voltage violations were identified. Minor high voltage violations occur
post-contingency at the Broadview 345 kV station. These high voltages are
related to set an initial voltage of 1.056 pu at Broadview 345 kV based on the
Broadview 297 MW PSCAD study. These violations can be ignored by
modifying the voltage profile if required.
 For the double contingency of the BA-Rio Puerco 345 kV lines:
o Overloads are identified on the BA 345/115 kV transformer and the 115
kV systems out of the BA 115 kV station.
o Overload is identified on the El Cabo-BA 345 KV line. This line is fully
loaded pre-contingency, with slight (2%) post-contingency overloads
resulting from reduced post-contingency voltages.
o A Remedial Action Scheme is planned for this contingency to trip the
Taiban Mesa-Blackwater 345 kV line to maintain acceptable system
performance, but was not modeled in the analysis.
Overall, it can be concluded from the contingency analysis that no substantial violations
occurred in the monitored areas and zones (Table 3-2). Thus an acceptable TPL
performance is achieved.
2. Voltage stability margin based on QV analysis showed that:
30




Positive reactive margin is seen at Guadalupe 345 kV for all studied
contingencies.
With increased power injections on BB line, there is a significant decrease in the
reactive margin but positive reactive margin is maintained for all normal and
contingency conditions when the system is stressed 5% beyond the maximum
transfer on the line.
Additional VAR support is needed at the Guadalupe 345 kV station if voltages of
105% percent of nominal are desired under maximum loading.
The Rio Puerco SVC shows relatively high capacitive output when Guadalupe
voltage is at the low side.
Overall, the QV analysis shows that for the analyzed outages, positive reactive margin
is maintained at Guadalupe 345 kV in the voltage range of 0.95 to 1.05 pu. Thus the
BB line transfer meets the WECC voltage stability margin criteria.
3. Dynamic simulation on the study base case with selected N-1 and N-2 contingencies
showed that:

Adequate system dynamic performance and adequate post-fault voltage
recoveries are achieved.

All the BB line wind power plants are able ride-through the studied faults.
4. Dynamic simulation on a sensitivity case with selected N-1 contingencies demonstrated
that:

With Blackwater HVDC in service with 15 MW E-W power level, system stability
is maintained for all N-1 contingencies.

All the BB line wind power plants and the Blackwater HVDC are able to ridethrough the studied faults
The PSLF studies thus did not identify a need for additional voltage support beyond the
Guadalupe SVC for the 1000 MW full buildout scenario. The system was found to meet the
TPL criteria and the WECC voltage stability margin criteria. All the wind farms on the BB line
were found able to ride through the studied faults with adequate post-fault voltage recoveries.
However, the limitations of the positive sequence models used in this study cannot guarantee
that a synchronous condenser at Blackwater station is not required to insure sufficient short
31
circuit capacity in the full buildout scenario for inverter based generation2. PSCAD studies (3phase model) are being performed in a separate study to evaluate whether a synchronous
condenser at Blackwater station will be required to support the power injection conditions as
stated above.
2
WECC White Paper: Value and Limitations of the Positive Sequence Generic Models of
Renewable Energy Systems
https://www.wecc.biz/_layouts/15/WopiFrame.aspx?sourcedoc=/Administrative/White%20Pape
r%20Generic%20Model%20Limitations%20December%202015.docx&action=default&DefaultIt
emOpen=1
32
6 References
[1] “ITA - Broadview Full Buildout Affected System PSLF Study - Mar 01 2016
clean.pdf”, ABB, March, 2016.
[2] Emails from Brett Rollow of Pattern Energy, Monday, March 28, 2016
[3] Technical Data_125MVA_HICO, March 2016.
[4] “PNM Wind Data Request_Check List_Iberdrola 01142016.docx”, April 2016.
[5] Email from PNM “RE_ [External] RE_ Line impedance values for new 345 kV line at El
Cabo”, April 11, 2016.
[6] ABB Technical Report E14417_0070_r0, “Rio Puerco SVC PSLF Model”, August
2015.
[7] ABB Technical Report 1JNL100120-027, “Blackwater HVDC Upgrade Project Main
Circuit Parameters and Reactive Power Compensation”, October, 2008
33
7 Appendices
Appendix A. Contingency Analysis Results, nominal load on BB line
The voltage and thermal violations can be found in document:
Appendix A.xlsx
Voltage and thermal violations
Appendix B. Dynamic Simulation Plots
The dynamic simulation plots can be found in documents:
Appendix B-1.pdf
DYNAMIC SIMULATION PLOTS WITH GUAD SVC GAIN SETTING 1
Appendix B-2.pdf
Dynamic simulation plots with Guad SVC gain setting 2, reduced Ki
Appendix B-3.pdf
Dynamic simulation plots with Guad SVC gain setting 3, reduced Ki
Appendix C. Sensitivity Dynamic Simulation Results
The sensitivity dynamic simulation plots can be found in documents:
Appendix C-1.pdf
Sensitivity case dynamic simulation plots with Guad SVC gain setting 1
Appendix C-2.pdf
Sensitivity case dynamic simulation plots with Guad SVC gain setting 2, reduced Ki
Appendix C-3.pdf
Sensitivity case dynamic simulation plots with Guad SVC gain setting 3, reduced Ki
34