q37 generator interconnection interconnection facilities study · 9/20/2011 · ge wind turbine...

Q37 Facilities Study Report Dated 9/20/2011

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Q37 Generator Interconnection

Interconnection Facilities Study

APS Contract No. 52401

By

Arizona Public Service Company Transmission Planning

September 20, 2011


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Table of Contents

I. INTRODUCTION ........................................................................................ 2

II. POINT OF INTERCONNECTION .............................................................. 3

III. INTERCONNECTION FACILITIES ............................................................ 4

IV. COST SUMMARY AND SCHEDULES ...................................................... 5

V. ADDITIONAL REQUIREMENTS AND STANDARDS ............................... 6

List of Appendices Appendix A – Q37 interconnection plan Appendix B – Network costs estimates Appendix C – Transmission Providers Interconnection Facilities cost

estimates Appendix D – Project milestones Appendix E – Transient stability analysis using GE 1.6 MW WTG model

I. Introduction In the spring 2011 Arizona Public Service (APS) performed a Large Generator Facilities Study (FaS) in response to a valid interconnection request from a customer identified herein as Q37. This report documents APS’s response to that request. Along


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with providing costs and schedules for interconnecting to facilities APS controls, other relevant issues are also discussed in this report for the interconnection and operation of the proposed Q37 300 MW wind farm. Customer Q37 has requested to interconnect a 300 MW (net) wind farm into the APS’s Cholla 500 kV transmission line through a new radial 500 kV transmission line 9 miles in length constructed to the west of the switchyard. The new transmission line will be on the customer side of the POI and will be owned by the customer. In addition, customer Q37 has requested Energy Resource Interconnection Service under APS’s OATT (Open Access Transmission Tariff). Design of the network facilities on the APS side of the POI will consist of two 500 kV breakers and 4 disconnect switches, bus facilities, protection and control equipment, communications equipment and structural facilities necessary for the interconnection.

When the initial Interconnection Request was made by Q37, the customer elected to pursue a Generation Interconnection Feasibility Study and later be a part of a cluster System Impact Study. As an Energy Resource Interconnection Service facility, the delivery of the output of the Q37 Generating Facility beyond the Point of Interconnection (POI) would be on an “as-available” basis only. The delivery of the Q37 output would be subject to the firm or non-firm transmission capacity that may be available when a transmission service request is made and, as a consequence, is subject to curtailment. Nothing in this report constitutes an offer of transmission service or confers upon the Interconnection Customer, any right to receive transmission service.

Figure 1 shows the geographic location of the proposed Q37 interconnection near

the Cholla 500 kV switching station. The requested In-Service Date for the Q37 Generating Facility is scheduled for 12/1/13. This date can be met by the proposed interconnection facilities described in this report with a start of construction activities on August 2012 and a completion of activities by October 2013 or approximately 14 months to allow for plant testing.

II. Point of Interconnection APS owns, operates and maintains the Cholla switching station and its transmission facilities except for the Cholla-Sugarloaf 500 kV line. Usage of the Cholla-Pinnacle Peak path (WECC Path 50), the Cholla-Saguaro 500 kV line and the Cholla-Four Corners 345 kV transmission path will require a transmission service request from APS’s OASIS site to determine the amount of available transmission capacity for their respective facilities. Fig. 1 shows the approximate geographic location of the customers wind farm along with the various transmission paths in eastern Arizona.


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Fig 2. Interconnection plan for customer Q37 at the Cholla 500 kV switching station.

IV. Cost Summary and Schedules Table 1 shows the interconnection and network costs for customer Q37’s project and the associated schedules for the interconnection plan. Construction schedule estimates are from the date customer Q37 provides written authorization to start construction, provided all interconnection agreements and funding arrangements are in place. The estimates were attempted to be within +/-10% accuracy as requested in the Facilities Study Agreement, noting that APS uses the very same estimation process for its own projects. Network project costs and Transmission Interconnection Facility costs can


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be found in Appendix B and C, respectively. The project milestones are given in Appendix D.

Table 1. TP Interconnection Facility and local network costs. Network

Upgrade Costs

Transmission Providers’

Interconnection Facility costs

APS labor $ 336,603 $ 106,289 Outside services-contractors

$ 396,930 $ 540,350

Outside services- other

$ 0 $ 0

Materials-Warehouse

$ 0 $ 0

Materials-Drop Ship

$ 1,307,436 $ 927,274

Per Diem $ 8,250 $ 1,000 Land Services $ 0 $ 0 Subtotal $ 2,049,219 $ 1,547,913 Grand Total $ 3,597,132 14 months

V. Additional Requirements and Standards In November, the customer indicated that they were planning to use a different GE wind turbine generator (WTG) for the wind farm. Consequently, the change in (1.5 MW to 1.6 MW) WTG model required a re-run of the transient stability analysis to verify that the performance of the plant was still acceptable. Results of the transient stability analysis should that the new model still performed acceptably for this project. A copy of the new transient stability analysis is contained in Appendix E. Finally, the customer will be required to meet the low-voltage ride through (LVRT) standard in APS’s OATT as well as the +/-.95 power factor standard.

Appendix A

Q37 interconnection plan

Appendix B

Network costs estimates

2011 Construction Load Calculation

Project Fact Sheet-To be completed by Estimator

Estimator Planner

Work Order Number

Description

Scope

System

APS Ownership Percentage

Customer/Participant Ownership Contract Attached

Network Upgrades Interconnection

CBI CBI Number

Load Calculation-Estimator to complete all shaded areas

Direct CostsResource Category

Labor Rate Qty Direct Costs 113 902 903 911 912 913 915 920 922 931 Total Loads Total Project

19.00% 7.00% 1.00% 37.00% 3.16% 13.54% 48.96% 1.00% 6.96% 0.57%

APS Labor (100-199) 50.00$ 2638 131,900$ 25,061 10,987 1,570 58,076 21,245 76,842 10,923 204,703 336,603 Material-Warehouse (300) -$ - - - Materials-Drop Ship (305) 1,300,000$ 7,436 7,436 1,307,436 Outside Services-Contractors (800-869)

(879-899) 393,000$ 3,930 3,930 396,930 Outside Services-Other (800-869)

(879-899) -$ - - - Equipment Rentals (601-607) -$ - - Per Diem (400-479) 8,250$ - 8,250

1,833,150$ 25,061 10,987 1,570 58,076 - 21,245 - 76,842 3,930 10,923 7,436 216,069 2,049,219

For WA Routing: Add PR Loads to Direct Costs (113, 902, 903, 911) 95,693 Total Directs for WA Routing 1,928,843

Total Overheads 120,375 Total Project 2,049,219

Yes

Tinseth

Yes

To be completed by estimator

New 500kV line bay at Cholla for Q37

New 500kV position w/2 breakers and 4 switches

Billed Special/CapitalOverhead Load Calculation

0%

0%

Appendix C

Transmission Providers

Interconnection Facilities

Cost Estimates

2011 Construction Load Calculation

Project Fact Sheet-To be completed by Estimator

Estimator Planner

Work Order Number

Description

Scope

System

APS Ownership Percentage

Customer/Participant Ownership Contract Attached

Network Upgrades Interconnection

CBI CBI Number

Load Calculation-Estimator to complete all shaded areas

Direct CostsResource Category

Labor Rate Qty Direct Costs 113 902 903 911 912 913 915 920 922 931 Total Loads Total Project

19.00% 7.00% 1.00% 37.00% 3.16% 13.54% 48.96% 1.00% 6.96% 0.57%

APS Labor (100-199) 50.00$ 833 41,650$ 7,914 3,469 496 18,338 6,708 24,264 3,449 64,639 106,289 Material-Warehouse (300) -$ - - - Materials-Drop Ship (305) 922,000$ 5,274 5,274 927,274 Outside Services-Contractors (800-869)

(879-899) 535,000$ 5,350 5,350 540,350 Outside Services-Other (800-869)

(879-899) -$ - - - Equipment Rentals (601-607) -$ - - Per Diem (400-479) 1,000$ - 1,000

1,499,650$ 7,914 3,469 496 18,338 - 6,708 - 24,264 5,350 3,449 5,274 75,263 1,574,913

For WA Routing: Add PR Loads to Direct Costs (113, 902, 903, 911) 30,217 Total Directs for WA Routing 1,529,867

Total Overheads 45,046 Total Project 1,574,913

Yes

Tinseth

No

To be completed by estimator

New 500kV line bay at Cholla for Q37

New 500kV line exit for Q37 w/ 1 switch, and 4 A-frames

Billed Special/CapitalOverhead Load Calculation

0%

0%

Appendix D

Project milestones

Q37 Milestone Schedule (5/28/2011)

Executed and funded LGIA/SGIA/E&P agreement Interconnection Customer

APS begin engineering activities 2 weeks after Funded LGIA/SGIA/E&P Agreement and Kickoff Meeting

Transmission Provider

APS begin procurement of long lead materials (6-8 months) Transmission Provider

APS complete substation site construction 4 months after start of site construction


Complete communications activities required for APS Substation Transmission Provider

Complete line/relay work to complete substation cut-in 3 weeks after outage begins


Initial synchronization 1 week after APS substation cut-in complete Transmission Provider

Customer C.O.D. 2 weeks after initial synchronization. Interconnection Customer

Milestone/Date Responsible Party

Appendix E

Transient stability analysis using

GE 1.6 MW WTG model

A subsidiary of Pinnacle West Capital Corporation

Q37 Transient Stability Re-Study

DRAFT

Facilities Study

APS Contract No. XXXXX

By

Arizona Public Service Company Transmission Planning

December 2, 2010

Version 1.0 - Draft

Prepared by Utility System Efficiencies, Inc.

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FACILITIES STUDY

Q37 Transient Stability Re-Study

TABLE OF CONTENTS

EXECUTIVE SUMMARY .............................................................................................................................. 2 1 STUDY DESCRIPTION AND ASSUMPTIONS ..................................................................................... 3

1.1 Project Modeling ............................................................................................................................. 3 1.2 Transient Stability Analysis ............................................................................................................. 4

LIST OF APPENDICES

Appendix A – Transient Stability Modeling

Appendix B – Transient Stability Plots

APS Q37 Transient Stability Analysis for Facilities Study

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EXECUTIVE SUMMARY The Applicant submitted new generator and transformer data for the Facilities Study. The planned capacity and power factor capability of the project did not change, requiring a re-study of only the transient stability portion of the System Impact Study.

Figure 1. Q37 Interconnection

#1

(FOUR CORNERS) CHOLLA

(69kV)

Path 22(B)

(69kV)

345kV

230kV

500kV

#2 #3 #4 SUGARLOAF

(2009)

(SAGUARO)

(Pinnacle Peak)

Mazatzal (2013)

Preacher Canyon

(Leupp) (SILVER KING)

Path 50

Path 54

Q#37 (300MW)

SRP Q#3 (700MW)

CORONADO

Concept Capacity Project

(2018 case only)

SRP Q#7 (500MW)


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1 STUDY DESCRIPTION AND ASSUMPTIONS This transient stability re-study utilized case 18 from the SIS which is a 2011 WECC basecase with SRP Q3 and APS Q1 modeled in the case. This case also has the withdrawn APS Q50 project which was an 8 MW capacity increase on Cholla Unit 4. This project was removed from the case.

1.1 Project Modeling The modeling of Q37 was revised by the Applicant for the Facilities Study. The Applicant indicated the project will consist of General Electric 1.5 MW turbines. Figure 2 depicts how the project was modeled in the power flow case. Three individual generators and dedicated transformers were modeled to represent three equivalent internal feeder systems. The new transient stability data was provided by the Applicant. The new model required use of the most recent version of GE PSLF 17.0_07.

Figure 2. Q37 Arrangement at Cholla

Q37 500kV

TO CHOLLA

Queue #37 (300MW)

34.5kV

690V

34.5kV

690V

34.5kV

690V


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1.2 Transient Stability Analysis 44 transient stability outages were simulated. Many of the transient stability simulations met Western Electricity Coordinating Council (WECC) Disturbance Performance Criteria. As discussed in the Reliability Criteria section of the SIS 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. Consistent with the findings in the SIS, transient stability concerns were observed at the APS Q1 Desert Rock project following a three phase fault on either 500kV line terminating at the Desert Rock 500kV bus. This was identified at a Pre-existing issue in the SIS and will not be attributed to the interconnection. The switch to the GE wind turbines does not appear to cause any transient stability concerns. Appendix B1

contains transient stability plots of selected contingencies that provide a representative illustration of the transmission system’s Post-Project performance.

1 Selected transient stability plots are provided in Appendix B; additional transient stability plots are available upon request.

APPENDIX A: TRANSIENT STABILITY MODELING

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Appendix A

TRANSIENT STABILITY MODELING


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Project Q37 - Dynamic Data Wind Turbine Model – Q37

Model Name: gewtg

Description Generator/converter model for GE wind turbines - Doubly Fed Asynchronous Generator (DFAG) and Full Converter (FC) Models

Invocation: gewtg [<n>] {<name> <kv>} <id>} : #<rl> {mva=<value>} Parameters:

EPCL MVA=121.04

Variable Description Project Data

Lpp Generator effective reactance (X’’), p.u. 0.80 dVtrp1 Delta voltage trip level, p.u. -0.25 dVtrp2 Delta voltage trip level, p.u. -0.50 dVtrp3 Delta voltage trip level, p.u. -0.70 dVtrp4 Delta voltage trip level, p.u. -0.85 dVtrp5 Delta voltage trip level, p.u. 0.10 dVtrp6 Delta voltage trip level, p.u. 0.15 dTtrp1 Voltage trip time, sec. 1.90 dTtrp2 Voltage trip time, sec. 1.20 dTtrp3 Voltage trip time, sec. 0.70 dTtrp4 Voltage trip time, sec. 0.20 dTtrp5 Voltage trip time, sec. 1.00 dTtrp6 Voltage trip time, sec. 0.10 fcflg Flag: 0 = DFAG; 1 = FC 0.0

Rrpwr LVPL ramp rate limit, p.u. 10.0 Brkpt LVPL characteristic breakpoint, p.u. (See notes G and H) 0.90 zerox LVPL characteristic zero crossing, p.u. (See notes G and H) 0.50

Notes:

1. Applicant-defined data values selected for this study are shown in red bold 2. The generator reactance and generator variables are in per unit on the generator MVA base. It is

recommended that the MVA base be specified in the dyd file by the entry mva=value after the record level.

3. The flux and active current commands from the converter control model, exwtge, are transferred via the variables genbc[k].efd and genbc[k].ladifd, respectively

4. The reactive and active current commands from the converter control model, ewtgfc, are transferred via the variables genbc[k].efd and genbc[k].ladifd, respectively

5. The generator will be tripped if the terminal voltage deviates from nominal (1 p.u.) by more than any of the voltage trip levels for more than the corresponding trip time. If any of the dVtrp values are set to zero, that trip level is ignored.

6. The voltage trip levels will vary for different wind farms. 7. A trip signal stored in genbc[k].glimt, which may be set by the exwtge, ewtgfc and wndtge models,

will also cause the generator to trip. 8. The LVPL characteristic for a DFAG machine is defined by the default data of brkpt = 0.9 p.u. and

zerox = 0.4 p.u. 9. The LVPL characteristic for a full converter machine is defined by brkpt = 0.9 p.u. and zerox = 0.4

p.u.


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10. The model will automatically detect if its input data is in an old format (16.2 or 16.3) and will correct it using the default data. The model writes messages to the terminal and to dylogfilep indicating what has been done

11. The “fix bad data” option will set the generator effective reactance, lpp, to 0.8 p.u.

Block Diagram, “gewtg” model


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Model Name: exwtge

Description Excitation (converter) control model for Double Fed Asynchronous Generator (DFAG) GE wind-turbine generators

Invocation: exwtge [<n>] {<name> <kv>} <id> [<nr>] {<namer> <kvr>} ! ! [<mon_i>] {<namei> <kvi>}[<mon_j>] {<namej> <kvj> <ck> <sec>:

Parameters:

EPCL MVA=121.04

Variable Description Project Data

varflg 1 = Qord from WindCONTROL emulation; -1 = Qord from vref (i.e., separate model); 0 = constant 1.0

Kqi Q control integral gain (see note 7) 0.10 Kvi V control integral gain 40.0

Vmax Maximum V at regulated bus (p.u.) 1.10 Vmin Minimum V at regulated bus (p.u.) 0.90 Qmax Maximum Q command (p.u.) 0.436 Qmin Minimum Q command (p.u.) -0.436

XIqmax Maximum Eq’’ (flux) command (pu) (see note 9) 1.45 XIqmin Minimum Eq’’ (flux) command (pu) (see note 9) 0.50

Tr WindCONTROL voltage measurement lag, sec. 0.02 Tc Lag between WindCONTROL output and wind turbine, sec. 0.15

Kpv WindCONTROL regulator proportional gain (see note 8) 18.0 Kiv WindCONTROL regulator integral gain (see note 8) 5.0 Vl1 Open Loop Control: Low voltage limit, p.u. -9999 Vh1 Open Loop Control: High voltage limit, p.u. 9999 Tl1 Open Loop Control: First low voltage time, sec 0.0 Tl2 Open Loop Control: Second low voltage time, sec 0.0 Th1 Open Loop Control: First high voltage time, sec. 0.0 Th2 Open Loop Control: Second high voltage time, sec. 0.0 Ql1 Open Loop Control: First low voltage Q command, p.u. 0.0 Ql2 Open Loop Control: Second low voltage Q command, p.u. 0.0 Ql3 Open Loop Control: Third low voltage Q command, p.u. 0.0 Qh1 Open Loop Control: First high voltage Q command, p.u. 0.0 Qh2 Open Loop Control: Second high voltage Q command, p.u. 0.0 Qh3 Open Loop Control: Third high voltage Q command, p.u. 0.0 pfaflg 1 = regulate power factor angle; 0 = regulate Q 0.0

Fn Fraction of WTGs in wind farm that are on-line 1.0 Tv Time constant in proportional path of WindCONTROL emulator, sec. 0.05

Tpwr Time constant in power measurement for PFA (Tp), sec. 0.05 Ipmax Max. Ip command, p.u. 1.22

Xc Compensating reactance for voltage control, p.u. 0.0 Kqd Gain on Q Droop function 0.0

Tlpqd Time constant in Q Droop funtion 5.0 Xqd Compensating reactance for Q Droop function 0.0

vermn Minimum limit on WindCONTROL regulated bus voltage error, pu -0.10 vermx Maximum limit on WindCONTROL regulated bus voltage error, pu 0.10

vfrz Voltage threshold to freeze integrators in WindCONTROL voltage regulator, pu 0.70


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Notes:

1. Applicant-defined data values selected for this study are shown in red bold 2. The Q order can either come from a separate model via the genbc[k].vref signal (varflg = -1) or

from the WindCONTROL emulation part of this model (varflg = 1). The WindCONTROL emulation represents the effect of a centralized WindCONTROL (aka Wind Farm Management System) control by an equivalent control on each wind turbine-generator model.

3. For the WindCONTROL emulator, voltage at a remote bus (e.g. system interface) can be regulated by entering the bus identification as the second bus ([<nr>] {<namer> <kvr>}) on the input record. Alternatively, generator terminal bus voltage can be regulated by omitting the second bus identification. The voltage reference, Vrfq, for the WindCONTROL emulator is stored in genbc[k].vref when varflg = 1

4. Any of the time constants may be zero 5. The time constant Tc reflects the delays associated with cycle time, communication (SCADA)

delay to the individual WTGs, and additional filtering in the WTG control 6. The operation of the open loop Q control (parameters Vl1 to Qh3) is defined by the table below.

The parameters can be set in various ways to model different control strategies. Setting a Q command parameter (e.g. Qh1) to 0 indicates that Qpfc from the “power factor control” is transmitted without modification. The open loop controls will reset if the voltage recovers beyond Vl1, Vl2, or Vh1, respectively. The default data disables this control as is the case on most units

7. Kqi can be tuned to obtain faster or slower response from the WindCONTROL. The time constant of the Q control loop is approximately equal to the equivalent reactance looking out from the generator terminals (= dV/dQ) divided by Kqi. The default value (0.1) assumes a desired time constant of 0.5 sec. and an equivalent reactance of 0.05 p.u. (on gen. MW base). This is appropriate for a single WTG connected to a stiff system and is currently the recommended setting. For constant Q regulation (varflg = pfaflg = 0), the value of Kqi should be set to a very small number, e.g. 0.001) since this control is a slow reset. Rapid power factor angle regulation (varflg = 0, pfaflg = 1) is currently used for European units when WindCONTROL is not employed. Kqi may need to be set to a larger value for these units

8. The default WindCONTROL gains, Kpv and Kiv, are appropriate when the system short circuit capacity beyond the point of interconnection of the wind farm is 5 or more times the MW capacity of the wind farm. For weaker systems, these values should be reduced, e.g. for SCC = 2., Kpv = 13 and Kiv = 2 are recommended

9. The model will automatically detect if its input data is in an old format (16.2 or 16.3) and will correct it using the default data. The model writes messages to the terminal and to dylogfilep indicating what has been done

10. The “fix bad data” option will do the following: a. If non-zero, set Tr, Tc, Tv, Tpwr to a minimum of 4*delt. b. If Xiqmax < 1.1 then set Xiqmax = 1.45 p.u. c. If Xiqmax < 0.0 or > 0.9 then set Xiqmax = 0.50 p.u.

11. The compensating reactance for voltage control, Xc, is used to synthesize a bus for regulating that is further into the power system then either the terminal bus or a remote bus. It is only available when a monitored branch is included in the invocation. If there is a monitored branch, then the regulated bus is the from-bus plus a projection into the system based on Xc*branch current. See note b) for other voltage regulation options

12. The Q Droop function, shown in Figure 4, is a relatively slow-acting function that reduces the change in voltage reference as reactive power changes. This improves coordination between multiple integral controllers regulating the same point in the system. With default data, the function is not active. To use this function, typical data would be Kqd = 0.04, Tlpqd = 5.0, Xqd = 0. There are three options for the reactive power input to this function: a. Default Q input is reactive power generated by this wind turbine generator. b. If a monitored branch is in the invocation, then the Q input is the reactive power flow in that branch. The from-bus of the monitored branch must be closest to the generator terminals. c. If a monitored branch is in the invocation and Xqd is non-zero, then the Q input is the reactive power flow in that branch plus a secondary term, Xqd*Im^2, where Im is the magnitude of the


Page A-6

current flowing in the monitored branch. The from-bus of the monitored branch must be closest to the generator terminals.

13. An arbitrary test signal can be injected into the terminal bus voltage regulator via model[@index]. sigval[0], as shown in Figure 3. A user-written dynamic model (epcmod) is used to generate the desired signal. The index of the wind turbine model (@index) can be obtained using the model_index function.

14. The WindFREE reactive power feature is available on GE’s DFAG wind turbines, however the reactive power capability of the equipment is reduced when operating with zero power output. If the WindFREE option is selected in the wndtge model and the power output is zero, then the reactive power range in the exwtge model is automatically set to +/- 0.12 pu, regardless of user input

Block Diagram, “exwtge” model


Page A-7

Model Name: wndtge

Description Wind turbine and turbine control model for GE wind turbines – Double Fed Asynchronous Generator (DFAG) and Full Converter (FC) Models

Invocation: wndtge [<n>] {<name> <kv>} <id> : [mwcap=<value>] Parameters:

EPCL MVA=121.04

Variable Description Project Data mwcap 1.6

Usize WTG unit size (1.5 or 3.6 for DFAG or 2.5 for FC) 1.5 Spdw1 Initial wind speed, m/s 14.0

Tp Pitch control constant, sec. 0.30 Tpc Power control time constant, sec. 0.05 Kpp Pitch control proportional gain 150.0 Kip Pitch control integral gain 25.0

Kptrq Torque control proportional gain 3.0 Kitrq Torque control integral gain 0.60 Kpc Pitch compensation proportional gain 3.0 Kic Pitch compensation integral gain 30.0

PImax Maximum blade pitch, deg 27.0 PImin Minimum blade pitch, deg 0.0 PIrat Blade pitch rate limit, deg/sec. 10.0

PWmax Maximum power order, p.u. (see note 8) 1.12 PWmin Minimum power order, p.u. 0.04 PWrat Power order rate limit, p.u./sec 0.45

Ht Rotor inertia constant, p.u. (on turbine MW base) 4.63 nmass = 1 for 1-mass model; = 2 for 2-mass model 1.0

Hg Generator rotor inertia constant, p.u. (on turb. MW base) 0.0 Ktg Shaft stiffness (p.u. torque/rad.) 0.0 Dtg Shaft damping (p.u. torque/p.u. speed) 0.0

Wbase Base mechanical speed (rad/sec) 0.0 Tw Rate limit washout time constant, sec. 1.0

Apcflg Active power control enable flag 0.0 Tpav Filter time constant on Pavail, sec. 0.15 Pa Active power point in frequency response curve, p.u. 1.0 Pbc Active power point in frequency response curve, pu 0.95 Pd Active power point in frequency response curve, pu 0.40 Fa Frequency value for Pa frequency response curve, pu 0.96 Fb Frequency value for Pbc frequency response curve, pu 0.996 Fc Frequency value for Pbc frequency response curve, pu 1.004 Fd Frequency value for Pd frequency response curve, pu 1.04

Pmax Maximum wind plant power, pu 1.0 Pmin Minimum wind plant power, pu 0.20 Kwi Gain for simple WindINERTIA model (see note I) 0.0

Dbwi Deadband, p.u. 0.0025 Tlpwi Low pass filter time constant, sec 1.02 Twowi Washout time constant, sec 5.5 Urlwi Up rate limit 0.1 Drlwi Down rate limit -1.0

Pmxwi Maximum output, p.u. 0.1 Pmnwi Minimum output, p.u. 0.0


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Wfflg WindFREE reactive power function flag (1=enabled) 0.0 Notes:

1. Applicant-defined data values selected for this study are shown in red bold 2. Per unit parameters, including H, are on base of turbine MW capability. If no value is entered for

mwcap, the generator MVA base is used. For an aggregate model of several wind turbines, mwcap should be the total rating

3. The wind speed (m/s) is stored in genbc[k].glimv and can be stepped in the edic table or varied by a user-written model

4. The model will always attempt to initialize to the initial generator power from the load flow, unless it exceeds PWmax or is less than PWmin. The wind speed required to produce the initial power with the blade pitch at its minimum, PIimin, is calculated. This will be used as the initial wind speed unless P is near PWmax and the specified wind speed, SPDw1, is greater than required. In this case, the wind speed is set at SPDw1 and the blade pitch is adjusted

5. The usize parameter is used to select the appropriate built-in values to model the different sizes of GE wind turbines

6. The default parameter values correspond to the DFAG wind turbine control model. Generally, the default values should be used, except usize, spdw1, and H (5.23 p.u. for usize = 3.6; 4.18 for usize = 2.5) unless different information is supplied by the manufacturer

7. The turbine-generator rotor speed is automatically initialized according to the turbine control design. The speed will be 1.2 p.u. for power levels above 0.75 p.u., but will decrease at lower power levels

8. A two-mass torsional model can be represented by including these parameters and changing the value of H to the turbine inertia constant. The two-mass model should not be used for the full converter wind turbine generator (i.e., 2.5 MW)

9. The model includes high and low wind speed cut-out for the turbine. For the DFAG machine this results in a generator trip. For a FC machine it is possible to inject or absorb reactive power (e.g., regulate voltage) at zero real power. Zero power may be the result of no wind, excessive wind, or an operator directive to curtail output. All scenarios may be simulated with this model. Pwmin should be 0 for FC machines

10. The active power control (APC) model and rate limiting function are shown in the lower portions of the block diagram. The APC model is a simple representation of the active power control requires by many European grid codes

11. When this model is used to represent DFAG machines, i.e., the 1.5 or 3.6 WTG, the dynamic braking resistor power is automatically set to zero

12. The FC machine allows zero power voltage regulation and does not trip on low rotor speed; low rotor speed tripping is enforced for DFAG machines, i.e., if genbc[k].speed < 0.1, the machine is tripped

13. The WindINERTIA control provides controlled inertial response to drops in frequency. A simplified model, as shown in Figure 3, of the actual control is included in wndtge. With default data, the function is not active. To use this function, typical data would be Kwi = 10., dbwi = 0.0025, Tlpwi = 1.0, Twowi = 5.5, urlwi = 0.1, drlwi = -1.0, Pmxwi = 0.1, Pmnwi = 0.0. To coordinate this function with other turbine controls, the proportional gain in the torque control, Kptrq, is reduced to 0.5, the integral gain, Kitrq, is reduced to 0.05, and the subsequent time constant, Tpc, is increased to 4 seconds, when this function is active (i.e., under-frequency event simulated). There is no reset, so these parameter changes are permanent for any given simulation

14. See Application Note 08-2 for detailed model description 15. The “fix bad data” option will do the following:

a. Set Tp, Tpc, Tw, Tpav, Tlpwi, Twowi, H to a minimum of 4*delt. b. If Pwmin < 0. then set Pwmin = 0. p.u.


Page A-9

Block Diagram, “wndtge” model


Page A-1

Figure A-1: Case 18 Flat Run

APPENDIX B: TRANSIENT STABILITY PLOTS

Page B-1

Appendix B

TRANSIENT STABILITY PLOTS


Page B-2

Transient Stability Plots: Q37 Facilities Study

Diagram Description Result 2011 Cases

Plot #1 Post-project case with APS Q1 and SRP Q3 Three-phase fault at Cholla 500kV followed by an outage of the Cholla-Saguaro 500kV Line Stable

Plot #2 Post-project case with APS Q1 and SRP Q3 Three-phase fault at Coronado 500kV followed by an outage of the Coronado-Silverking 500kV Line and dropping Coronado Unit 1

Stable

Plot #3 Post-project case with APS Q1 and SRP Q3 Three-phase fault at Cholla 500kV followed by an outage of the Cholla-Sugarloaf 500kV Line Stable

Plot #4 Post-project case with APS Q1 and SRP Q3 Three-phase fault at Cholla 345kV followed by an outage of the Cholla-Preacher Canyon 345kV Line Stable

Plot #5 Post-project case with APS Q1 and SRP Q3 Three-phase fault at Cholla 345kV followed by an outage of the Cholla-Four Corners 345kV Line Stable


Page B-3

Figure B-1: N-1 Cholla-Saguaro 500kV Line


Page B-4

Figure B-2: N-1 Coronado-Silverking 500kV Line


Page B-5

Figure B-3: N-1 Cholla-Sugarloaf 500kV Line


Page B-6

Figure B-4: N-1 Cholla-Preacher Canyon 345kV Line


Page B-7

Figure B-5: N-1 Cholla-Four Corners #1 345kV Line

q37 generator interconnection interconnection facilities study · 9/20/2011 · ge wind turbine...

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