Introduction (This introduction is not part of IEEE Std 421.5-2005.IEEE Recommended Practice for Excitation System Models for Power System Stability Studies.) Excitation system models suitable for use in large-scale system stability studies are presented in this recommended practice.With these models,most of the excitation systems currently in widespread use on large,system-connected synchronous machines in North America can be represented. In 1968,models for the systems in use at that time were presented by the Excitation System Subcommittee and were widely used by the industry.Improved models that reflected advances in equipment and better modeling practices were developed and published in the IEEE Transactions on Power Apparatus and Systems in 1981.These models included representation of more recently developed systems and some of the supplementary excitation control features commonly used with them.In 1992,the 1981 models were updated and presented in the form of recommended practice IEEE Std 421.5-1992.In 2005,this document was further revised to add information on reactive differential compensation,excitation limiters,power factor and var controllers,and new models incorporating proportional,integral,and differential (PID) control. The model structures presented are intended to facilitate the use of field test data as a means of obtaining model parameters.The models are,however,reduced order models and do not represent all of the control loops on any particular system.The models are valid for frequency deviations of +5%from rated frequency and oscillation frequencies up to 3 Hz.These models would not normally be adequate for use in studies of subsynchronous resonance or other shaft torsional interaction problems.Delayed protective and control features that may come into play in long-term dynamic performance studies are not represented.A sample set of data for each of the models,for at least one particular application,is provided. Notice to users Errata Errata,if any,for this and all other standards can be accessed at the following URL:http:// standards.ieee.org/reading/ieee/updates/errata/index.html.Users are encouraged to check this URL for errata periodically. Interpretations Current interpretations can be accessed at the following URL:http://standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights.By publication of this standard,no position is taken with respect to the existence or validity of any patent rights in connection therewith.The IEEE shall not be responsible for identifying patents or patent applications for which a license may be required to implement an IEEE standard or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. Copyright 2006 IEEE.All rights reserved
iv Copyright © 2006 IEEE. All rights reserved. Introduction Excitation system models suitable for use in large-scale system stability studies are presented in this recommended practice. With these models, most of the excitation systems currently in widespread use on large, system-connected synchronous machines in North America can be represented. In 1968, models for the systems in use at that time were presented by the Excitation System Subcommittee and were widely used by the industry. Improved models that reflected advances in equipment and better modeling practices were developed and published in the IEEE Transactions on Power Apparatus and Systems in 1981. These models included representation of more recently developed systems and some of the supplementary excitation control features commonly used with them. In 1992, the 1981 models were updated and presented in the form of recommended practice IEEE Std 421.5-1992. In 2005, this document was further revised to add information on reactive differential compensation, excitation limiters, power factor and var controllers, and new models incorporating proportional, integral, and differential (PID) control. The model structures presented are intended to facilitate the use of field test data as a means of obtaining model parameters. The models are, however, reduced order models and do not represent all of the control loops on any particular system. The models are valid for frequency deviations of ±5% from rated frequency and oscillation frequencies up to 3 Hz. These models would not normally be adequate for use in studies of subsynchronous resonance or other shaft torsional interaction problems. Delayed protective and control features that may come into play in long-term dynamic performance studies are not represented. A sample set of data for each of the models, for at least one particular application, is provided. Notice to users Errata Errata, if any, for this and all other standards can be accessed at the following URL: http:// standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for errata periodically. Interpretations Current interpretations can be accessed at the following URL: http://standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights. By publication of this standard, no position is taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE shall not be responsible for identifying patents or patent applications for which a license may be required to implement an IEEE standard or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. (This introduction is not part of IEEE Std 421.5-2005, IEEE Recommended Practice for Excitation System Models for Power System Stability Studies.)
Participants At the time this recommended practice was completed,the Working Group had the following membership: Les Hajagos,Chair D.C.Lee,Past Chair J.C.Agee Anne-Marie Hissel Shawn Patterson Mike Basler Joe Hurley Manfred Reimann Roger Beaulieu Ruediger Kutzner Graham Rogers Roger Berube Jim Luini Robert Rusch Murray Coultes Om Malik Rich Schaefer James Feltes Steve Miller Alexander Schneider Luc Gerin-Lajoie Richard Mummert Paul Smulders Arjun Godhwani Sandy Murdoch Jose Taborda Robert Grondin Robert Thornton-Jones The following members of the individual balloting committee voted on this standard.Balloters may have voted for approval,disapproval,or abstention. William Ackerman Anne-Marie Hissel Michael Newman J.C.Agee Adrienne Hendrickson Shawn Patterson Ali Al Awazi Ajit Hiranandani Manfred Reimann Sabir Azizi-Ghannad David Jackson James Ruggieri William Bloethe Innocent Kamwa Alexander Schneider Steven Brockschink Prabha Kundur Rich Schaefer Gustavo Brunello Ruediger Kutzner Winfried Stach Voith Keith Chow Lawrence Long Jose Taborda Gary Engmann Lisardo Lourido Shanmugan Thamilarasan James Feltes Omar Mazzoni Robert Thornton-Jones Robert Grondin Om Malik Gaeral Vaughn Randall Groves James Michalec James Wilson Jim Gurney G.Michel Ahmed Zobaa Charles Morse Copyright2006 IEEE.All rights reserved
Copyright © 2006 IEEE. All rights reserved. v Participants At the time this recommended practice was completed, the Working Group had the following membership: Les Hajagos, Chair D. C. Lee, Past Chair The following members of the individual balloting committee voted on this standard. Balloters may have voted for approval, disapproval, or abstention. J. C. Agee Mike Basler Roger Beaulieu Roger Berube Murray Coultes James Feltes Luc Gerin-Lajoie Arjun Godhwani Robert Grondin Anne-Marie Hissel Joe Hurley Ruediger Kutzner Jim Luini Om Malik Steve Miller Richard Mummert Sandy Murdoch Shawn Patterson Manfred Reimann Graham Rogers Robert Rusch Rich Schaefer Alexander Schneider Paul Smulders Jose Taborda Robert Thornton-Jones William Ackerman J. C. Agee Ali Al Awazi Sabir Azizi-Ghannad William Bloethe Steven Brockschink Gustavo Brunello Keith Chow Gary Engmann James Feltes Robert Grondin Randall Groves Jim Gurney Anne-Marie Hissel Adrienne Hendrickson Ajit Hiranandani David Jackson Innocent Kamwa Prabha Kundur Ruediger Kutzner Lawrence Long Lisardo Lourido Omar Mazzoni Om Malik James Michalec G. Michel Charles Morse Michael Newman Shawn Patterson Manfred Reimann James Ruggieri Alexander Schneider Rich Schaefer Winfried Stach Voith Jose Taborda Shanmugan Thamilarasan Robert Thornton-Jones Gaeral Vaughn James Wilson Ahmed Zobaa
The final conditions for approval of this standard were met on 25 October 2005.This standard was conditionally approved by the IEEE-SA Standards Board on 22 September 2005,with the following membership: Steve M.Mills,Chair Richard H.Hulett,Vice Chair Don Wright,Past Chair Judith Gorman,Secretary Mark D.Bowman Raymond Hapeman Glenn Parsons Dennis B.Brophy William B.Hopf Ronald C.Petersen Joseph Bruder Lowell G.Johnson Gary S.Robinson Richard Cox Hermann Koch Frank Stone Bob Davis Joseph L.Koepfinger* Malcolm V.Thaden Julian Forster* David J.Law Richard L.Townsend Joanna N.Guenin Daleep C.Mohla Joe D.Watson Mark S.Halpin Paul Nikolich Howard L.Wolfman T.W.Olsen *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K.Aggarwal,NRC Representative Richard DeBlasio,DOE Representative Alan H.Cookson,NIST Representative Michael D.Fisher IEEE Standards Project Editor vi Copyright 2006 IEEE.All rights reserved
vi Copyright © 2006 IEEE. All rights reserved. The final conditions for approval of this standard were met on 25 October 2005. This standard was conditionally approved by the IEEE-SA Standards Board on 22 September 2005, with the following membership: Steve M. Mills, Chair Richard H. Hulett, Vice Chair Don Wright, Past Chair Judith Gorman, Secretary *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K. Aggarwal, NRC Representative Richard DeBlasio, DOE Representative Alan H. Cookson, NIST Representative Michael D. Fisher IEEE Standards Project Editor Mark D. Bowman Dennis B. Brophy Joseph Bruder Richard Cox Bob Davis Julian Forster* Joanna N. Guenin Mark S. Halpin Raymond Hapeman William B. Hopf Lowell G. Johnson Hermann Koch Joseph L. Koepfinger* David J. Law Daleep C. Mohla Paul Nikolich T. W. Olsen Glenn Parsons Ronald C. Petersen Gary S. Robinson Frank Stone Malcolm V. Thaden Richard L. Townsend Joe D. Watson Howard L. Wolfman
Contents 1. Overyiew..... l.1 Scope.… 2. Normative references............ …2 3. Representation of synchronous machine excitation systems in power system studies.................... 4. Synchronous machine terminal voltage transducer and current compensator models........................4 5. Type DC-Direct current commutator exciters............. .6 5.1 Type DC1A excitation system model.... 5.2 Type DC2A excitation system model........... 7 8 5.3 Type DC3A excitation system model.8 5.4 Type DC4B excitation system model...... .9 6. Type AC-Alternator-supplied rectifier excitation systems 10 6.1 Type AC1A excitation system model............... .10 6.2 Type AC2A excitation system model...... .11 6.3 Type AC3A excitation system model......... .12 6.4 Type AC4A excitation system model........... 13 6.5 Type AC5A excitation system model.... …13 6.6 Type AC6A excitation system model...... .14 6.7 Type AC7B excitation system model...... 14 6.8 Type AC8B excitation system model...... …14 1. Type ST-Static excitation systems.......... .15 7.1 Type STIA excitation system model .16 7.2 Type ST2A excitation system model..... 17 7.3 Type ST3A excitation system model....... .18 7.4 Type ST4B excitation system model............. 18 7.5 Type ST5B excitation system model...... .19 7.6 Type ST6B excitation system model........... 19 7.7 Type ST7B excitation system model................ 20 8. Power system stabilizers. 21 8.1 Type PSS1A power system stabilizer model..... 8.2 Type PSS2B power system stabilizer model.... 21 22 8.3 Type PSS3B power system stabilizer model.... 23 8.4 Type PSS4B power system stabilizer model......... .24 Overexcitation limiters. .25 9.1 Field winding thermal capability.25 9.2 OEL types… …26 9.3 OEL model......... 27 Copyright2006 IEEE.All rights reserved. vii
Copyright © 2006 IEEE. All rights reserved. vii Contents 1. Overview.............................................................................................................................................. 1 1.1 Scope............................................................................................................................................ 1 2. Normative references........................................................................................................................... 2 3. Representation of synchronous machine excitation systems in power system studies........................ 2 4. Synchronous machine terminal voltage transducer and current compensator models ........................ 4 5. Type DC—Direct current commutator exciters................................................................................... 6 5.1 Type DC1A excitation system model.......................................................................................... 7 5.2 Type DC2A excitation system model.......................................................................................... 8 5.3 Type DC3A excitation system model.......................................................................................... 8 5.4 Type DC4B excitation system model .......................................................................................... 9 6. Type AC—Alternator-supplied rectifier excitation systems ............................................................. 10 6.1 Type AC1A excitation system model........................................................................................ 10 6.2 Type AC2A excitation system model........................................................................................ 11 6.3 Type AC3A excitation system model........................................................................................ 12 6.4 Type AC4A excitation system model........................................................................................ 13 6.5 Type AC5A excitation system model........................................................................................ 13 6.6 Type AC6A excitation system model........................................................................................ 14 6.7 Type AC7B excitation system model ........................................................................................ 14 6.8 Type AC8B excitation system model ........................................................................................ 14 7. Type ST—Static excitation systems .................................................................................................. 15 7.1 Type ST1A excitation system model......................................................................................... 16 7.2 Type ST2A excitation system model......................................................................................... 17 7.3 Type ST3A excitation system model......................................................................................... 18 7.4 Type ST4B excitation system model ......................................................................................... 18 7.5 Type ST5B excitation system model ......................................................................................... 19 7.6 Type ST6B excitation system model ......................................................................................... 19 7.7 Type ST7B excitation system model ......................................................................................... 20 8. Power system stabilizers.................................................................................................................... 21 8.1 Type PSS1A power system stabilizer model............................................................................. 21 8.2 Type PSS2B power system stabilizer model ............................................................................. 22 8.3 Type PSS3B power system stabilizer model ............................................................................. 23 8.4 Type PSS4B power system stabilizer model ............................................................................. 24 9. Overexcitation limiters....................................................................................................................... 25 9.1 Field winding thermal capability ............................................................................................... 25 9.2 OEL types .................................................................................................................................. 26 9.3 OEL model................................................................................................................................. 27
10.Underexcitation limiters............ .29 10.1 Circular characteristic UEL (Type UELI model).30 10.2 Piecewise linear UEL (Type UEL2 model)......31 11.Power factor and reactive power controllers and regulators.. .34 11.IVoltage adjuster 35 11.2 PF controller Type I........ .36 11.3 Var controller Type I. 36 11.4 PF controller Type II. 11.5 Var controller Type II....... 38 .38 12.Supplementary discontinuous excitation control.... .39 12.General....... 39 12.2 Type DEC1A discontinuous excitation control... .39 12.3 Type DEC2A discontinuous excitation control...... .40 12.4 Type DEC3A discontinuous excitation control........... .41 Annex A (normative)Nomenclature........................ .42 Annex B(normative)Per unit system........ .49 Annex C(normative)Exciter saturation and loading effects.50 Annex D (normative)Rectifier regulation.52 Annex E (normative)Representation of limits..53 Annex F(informative)Avoiding computational problems by eliminating fast feedback loops.................57 Annex G(normative)Paths for flow of induced synchronous machine negative field current..................62 Annex Hinformative)Sample data.64 Annex I (informative)Manufacturer model cross reference..... ..81 Annex J (informative)Bibliography........ .83 viii Copyright2006 IEEE.All rights reserved
viii Copyright © 2006 IEEE. All rights reserved. 10. Underexcitation limiters..................................................................................................................... 29 10.1 Circular characteristic UEL (Type UEL1 model)...................................................................... 30 10.2 Piecewise linear UEL (Type UEL2 model)............................................................................... 31 11. Power factor and reactive power controllers and regulators.............................................................. 34 11.1 Voltage adjuster ......................................................................................................................... 35 11.2 PF controller Type I................................................................................................................... 36 11.3 Var controller Type I ................................................................................................................. 36 11.4 PF controller Type II.................................................................................................................. 38 11.5 Var controller Type II ................................................................................................................ 38 12. Supplementary discontinuous excitation control............................................................................... 39 12.1 General....................................................................................................................................... 39 12.2 Type DEC1A discontinuous excitation control ......................................................................... 39 12.3 Type DEC2A discontinuous excitation control ......................................................................... 40 12.4 Type DEC3A discontinuous excitation control ......................................................................... 41 Annex A (normative) Nomenclature ............................................................................................................. 42 Annex B (normative) Per unit system............................................................................................................ 49 Annex C (normative) Exciter saturation and loading effects......................................................................... 50 Annex D (normative) Rectifier regulation..................................................................................................... 52 Annex E (normative) Representation of limits .............................................................................................. 53 Annex F (informative) Avoiding computational problems by eliminating fast feedback loops ................... 57 Annex G (normative) Paths for flow of induced synchronous machine negative field current .................... 62 Annex H (informative) Sample data.............................................................................................................. 64 Annex I (informative) Manufacturer model cross reference ......................................................................... 81 Annex J (informative) Bibliography.............................................................................................................. 83