Active Standard

IEEE 421.6-2017

IEEE Recommended Practice for the Specification and Design of Field Discharge Equipment for Synchronous Machines

This document is intended to serve as basic reference for the specification and design of field discharge circuits for synchronous machines. It is also intended to provide detailed information about field discharge that complements standards "IEEE 421.4.-2004 Guide for Preparation of Excitation System Specification" and includes many aspects of the withdrawn standard "ANSI/IEEE C37.18.1979 Standard Enclosed Field Discharge Circuit Breakers". This document shows the most employed field discharge circuits and defines the main design criteria and conditions for the main components of field discharge circuit for synchronous machines.

Sponsor Committee
PE/EDPG - Energy Development & Power Generation
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Active Standard
PAR Approval
Board Approval
ANSI Approved:

Working Group Details

IEEE Power and Energy Society
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Sponsor Committee
PE/EDPG - Energy Development & Power Generation
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Working Group
ESCS - WG 421.6 - Excitation Systems and Controls Subcommittee (ESCS) -WG 421.6
IEEE Program Manager
Vanessa Lalitte
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Working Group Chair
Robert Thornton-Jones

Other Activities From This Working Group

Current projects that have been authorized by the IEEE SA Standards Board to develop a standard.

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Standards approved by the IEEE SA Standards Board that are within the 10-year lifecycle.


IEEE Guide for Identification, Testing, and Evaluation of the Dynamic Performance of Excitation Control Systems

This guide includes criteria, definitions, and test procedures for evaluating the dynamic performance of excitation control systems for synchronous machines as applied by electric utilities.

Learn More About 421.2-2014

These standards have been replaced with a revised version of the standard, or by a compilation of the original active standard and all its existing amendments, corrigenda, and errata.


IEEE Standard Definitions for Excitation Systems for Synchronous Machines

Elements and commonly used components in excitation control systems and for excitation systems as applied to synchronous machines are defined. The primary purpose of the standard is to provide a vocabulary for writing excitation systems specifications, evaluating excitation system performance, specifying methods for excitation system tests, and preparing excitation system standards. It is also intended to serve as an educational aid for those becoming acquainted with excitation systems.

Learn More About 421.1-1986


IEEE Standard for High-Potential Test Requirements for Excitation Systems for Synchronous Machines

High-potential test voltages for excitation systems used with synchronous machines are established. Test voltages are established based on whether equipment is connected to the exciter power circuit or is electrically isolated from the exciter power circuit.

Learn More About 421.3-1997


IEEE Guide for the Preparation of Excitation System Specifications

This guide is intended to provide to the specification writer the information to prepare a specification for the purchase of an excitation system. This guide is presented in narrative form with descriptions of functions typical of excitation systems. Narrative is provided describing types of excitation systems and information required for sizing the excitation system.

Learn More About 421.4-2004

These standards have been removed from active status through a ballot where the standard is made inactive as a consensus decision of a balloting group.

No Inactive-Withdrawn Standards

These standards are removed from active status through an administrative process for standards that have not undergone a revision process within 10 years.

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