scope:

Foreword 

This guide is intended as resource material for writers preparing a specification for procurement of an excitation system for a synchronous machine. It is intended that IEEE Std 421.1^™-1986, IEEE Std 421.2™-1990, IEEE Std 421.3™-1997, and IEEE Std 421.5™-1992 be used in conjunction with this guide in preparing the specification. This guide is not intended to be a fill-in-the-blanks guide but a narrative description of items and functions that should be considered in preparing excitation system specifications. Some of the information presented in this guide may be unnecessary for the writer's particular specification. One should judge the applicability of information to be included in the writer's specification and remove all inapplicable portions. Some tutorial material is included for the user who may be relatively inexperienced in selecting parameters and requirements for each particular application.

It should also be noted that this document defines an excitation control system as one that includes the synchronous machine. The definition is included here for clarity as the term is not defined in IEEE Std 421.1-1986; however, it is included in IEEE 100, The Authoritative Dictionary of IEEE Standards Terms, Seventh Edition.

Suggestions for improvement of this specification guide are welcomed. They should be sent to the Secretary, IEEE Standards Board Institute of Electrical and Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08855, USA.

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.

Participants

The following is a list of participants in the Excitation Systems Subcommittee Working Group.

Richard C. Schaefer, Chair

The following members of the individual balloting committee voted on this guide. Balloters may have voted for approval, disapproval, or abstention.

When the IEEE-SA Standards Board approved this guide on 24 June 2004, it had the following membership:

Don Wright, Chair

Steve M. Mills, Vice 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 Cookson, NIST Representative

Savoula Amanatidis

IEEE Standards Managing Editor

Scope

This guide is intended to provide to the specification writer the necessary material for preparing a specification for the procurement of an excitation system for a synchronous machine. The information presented in this guide is given in narrative form with the descriptions and functions of particular items that should be examined in preparing the specifications. Some information presented in this guide may be inapplicable for a specific excitation system application, and it may be omitted in the writer's specification.

The term excitation control system is used throughout this guide. An excitation control system is a feedback control system that includes the synchronous machine and its excitation system. Figure 1 contains a block diagram of an excitation control system. An excitation system is the equipment providing field current for a synchronous machine, including all power, regulating, control, and protective elements. An exciter is the equipment that provides the field current for the excitation of a synchronous machine. A synchronous machine regulator couples the output variables of the synchronous machine to the input of the exciter through feedback and forward controlling elements for the purpose of regulating the synchronous machine output variables (see IEEE Std 421.1™-1986).¹ The influence of the power system upon the operation of the excitation control system must be considered when the synchronous machine is connected to the utility grid.