1、IEEE Std 421.1-2007(Revision ofIEEE Std 421.1-1986)IEEE Standard Definitions for Excitation Systems for Synchronous MachinesI E E E3 Park Avenue New York, NY10016-5997, USA15 July 2007IEEE Power Engineering SocietySponsored by theEnergy Development and Power Generation CommitteeIEEE Std 421.1-2007 (
2、Revision of IEEE Std 421.1-1986) IEEE Standard Definitions for Excitation Systems for Synchronous Machines Sponsor Energy Development and Power Generation Committee of the Power Engineering Society Approved 8 March 2007 IEEE-SA Standards Board Abstract: This standard defines elements and commonly us
3、ed components in excitation systems and contains definitions for excitation systems applied to synchronous machines. An included annex contains one-line block diagrams of some typical excitation systems. These are presented to illustrate the defined terminology referenced in this standard and clarif
4、y the understanding of the excitation control system. Keywords: definitions of excitation controls, excitation block diagrams, excitation control systems, excitation systems terminology, synchronous generator controls _ The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New Y
5、ork, NY 10016-5997, USA Copyright 2007 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 15 July 2007. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any indiv
6、idual standard for educational classroom use can also be obtained through the Copyright Clearance Center. Introduction This introduction is not part of IEEE Std 421.1-2007, IEEE Standard Definitions for Excitation Systems for Synchronous Machines. This standard defines elements and commonly used com
7、ponents in excitation systems and contains definitions for excitation systems applied to synchronous machines. For general requirements of a synchronous machine refer to IEEE Std C50.12 and IEEE Std C50.13.aA synchronous machine excitation control system operating under automatic control is a feedba
8、ck control system. Thus, the Terminology of the Excitation System Subcommittee Working Group of the Energy Development and Power Generation (ED or 2) 100 C for field windings designed to operate at rating with a temperature rise greater than 60 C. NOTEThis defines one per unit excitation system volt
9、age for use in computer representation of excitation systems.43.5 air-gap line: The extended straight line part of the no-load saturation curve of the synchronous machine. 3.6 alternator-rectifier exciter: An exciter whose energy is derived from an alternator and converted to direct current by recti
10、fiers. The exciter includes an alternator and power rectifiers that may be either noncontrolled or controlled, including gate circuitry. It is exclusive of input control elements. The alternator may be driven by any type of prime mover, most commonly the shaft of the synchronous machine. The rectifi
11、ers may be stationary or rotating with the alternator shaft. 3.7 automatic control: In excitation control system usage, automatic control refers to maintaining synchronous machine terminal voltage at a predetermined level without operator action, over the operating range of the synchronous machine.
12、NOTEVoltage regulation may be modified by the action of load current compensators, power factor or var controllers, power system stabilizers, or may be constrained by the action of various limiters included in the excitation system. 1The IEEE publications listed in this document are trademarks of th
13、e Institute of Electrical and Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08855-1331, USA (http:/standards.ieee.org). 2IEEE publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, Piscataway, NJ 08855-1331, USA (http:/standards.ieee.org). 3The n
14、umbers in brackets correspond to those of the bibliography in Annex B. 4Notes in text, tables, and figures of a standard are given for information only and do not contain requirements needed to implement this standard. 2 Copyright 2007 IEEE. All rights reserved. IEEE Std 421.1-2007 IEEE Standard Def
15、initions for Excitation Systems for Synchronous Machines 3.8 automatic voltage regulator (AVR): A term often used to designate either the voltage regulator alone or the complete control system comprised of limiters, etc. See also: synchronous machine regulator. 3.9 autotracking: A function that caus
16、es the output of a control channel in the standby mode to follow the action of an active control channel; for example, autotracking of the manual control to follow the automatic control. Also called a follower. 3.10 auxiliary winding excitation system: An excitation system whose energy is derived fr
17、om a separate dedicated power winding in the main generators stator. NOTESee Figure A.10. 3.11 brushless exciter: An alternator-rectifier exciter employing rotating rectifiers with a direct connection to the synchronous machine field, thus eliminating the need for brushes. NOTESee Figure A.6. 3.12 b
18、umpless transfer: A transfer between two control modes that results in negligible change in synchronous machine output. See also: null balance. 3.13 ceiling current: The maximum field current that the excitation system is designed to supply. Typically, this is related to the thermal capability of th
19、e excitation system equipment or the synchronous machine field circuit capability. See also: overexcitation limiter. 3.14 ceiling voltage: The maximum direct voltage that the excitation system is designed to supply from its terminals under defined conditions. NOTE 1 The no-load ceiling voltage is de
20、termined with the excitation system supplying minimal current. NOTE 2 The ceiling voltage under load is determined with the excitation system supplying synchronous machine rated field current. NOTE 3 For an excitation system whose supply depends on the synchronous machine voltage and (if applicable)
21、 current, the nature of power system disturbance and specific design parameters of the excitation system and the synchronous machine influence the excitation system output. For such systems, the ceiling voltage is determined considering a specified supply voltage (usually rated voltage) and (if appl
22、icable) synchronous machine current. NOTE 4 For excitation systems employing a rotating exciter, the ceiling voltage is determined at rated speed. 3.15 compound source-rectifier exciter: An exciter whose energy is derived from the currents and potentials of the ac terminals of the synchronous machin
23、e and converted to direct current by rectifiers. The exciter includes the power transformers (current and potential), reactors (if required), and rectifiers that may be either noncontrolled or controlled, including gate circuitry. It is exclusive of input control elements. 3.16 crowbar: In excitatio
24、n system usage, a circuit designed to provide a conduction path for field current flow to prevent excessive field voltage. Triggered semiconductors with series resistors or inductors are commonly used. Non-linear resistors may alternatively provide this function. NOTESee Figure A.17b. 3.17 current b
25、oost: An excitation system auxiliary supply that acts to increase the available power supplied to the field winding, typically during fault conditions where the terminal voltage is lower and current is higher than normal. 3.18 current boost exciter: An exciter whose energy is derived from currents a
26、t the ac terminals of the synchronous machine and converted to direct current by rectifiers. The current boost system output is added directly with a potential source exciter rectifier as a separate rectifier system. The current boost system may include power current transformers, and either noncont
27、rolled rectifiers or controlled rectifiers, with gate circuitry. NOTESee Figure A.14 and Figure A.15. 3 Copyright 2007 IEEE. All rights reserved. IEEE Std 421.1-2007 IEEE Standard Definitions for Excitation Systems for Synchronous Machines 4 Copyright 2007 IEEE. All rights reserved. Figure 13.19 dc
28、field breaker: A circuit breaker used to disconnect the excitation system from the generator or exciter field. See also: de-excitation. 3.20 dc generator-commutator exciter: An exciter whose energy is derived from a dc generator. The exciter includes a dc generator with its commutator and brushes. I
29、t is exclusive of input control elements. The exciter may be driven by a motor or any type of prime mover, most commonly by the shaft of the synchronous machine. 3.21 dc regulator: See: manual control. 3.22 de-excitation: The removal of the excitation and field discharge of the synchronous machine,
30、main exciter, or pilot exciter. NOTEDe-excitation may be accomplished by various means, such as a field discharge circuit breaker, dc field breaker, ac field breaker, crowbar, free wheeling diode, phase-back control of controlled rectifiers, or a combination of these. 3.23 digital excitation system:
31、 A common nomenclature for describing an excitation system for a synchronous machine where some, if not all, of the functionality is implemented in a digital processor. As a minimum, the AVR control function would be expected to be implemented digitally in such a system. It is likely that the limite
32、r functions and optional var/pf or PSS controls are also implemented in the same digital-based control. NOTESee B6. 3.24 discharge resistor: A resistor that, upon interruption of excitation source current, is connected across the field winding of a synchronous machine or an exciter to limit the tran
33、sient voltage in the field circuit and to hasten the decay of field current of the machine. 3.25 discontinuous excitation control: A control function that acts to rapidly change synchronous machine excitation to a level different than that called for by the voltage regulator and power system stabili
34、zer, for a period of time following a system fault or disturbance. Also known as discrete field forcing or transient excitation boosting. 3.26 excitation control system: The feedback control system that includes the synchronous machine and its excitation system. The term is used to distinguish the p
35、erformance of the synchronous machine and excitation system in conjunction with the power system from that of the excitation system alone. NOTESee Figure 1. EXCITATION SYSTEMEXCITATION CONTROL SYSTEMBlock diagram of excitation control system 3.27 excitation system: The equipment providing field curr
36、ent for a synchronous machine, including all power, regulating, control, and protective elements. IEEE Std 421.1-2007 IEEE Standard Definitions for Excitation Systems for Synchronous Machines 5 Copyright 2007 IEEE. All rights reserved. Figure 23.28 excitation system duty cycle: An initial operating
37、condition and a subsequent sequence of events of specified duration to which the excitation system will be exposed. NOTEThe duty cycle usually involves a three-phase fault of specified duration that is located electrically close to the synchronous machine. Its primary purpose is to specify the duty
38、that the excitation system components can withstand without incurring mis-operation or damage. 3.29 excitation system nominal response: The rate of increase of the excitation system output voltage determined from the excitation system voltage response curve, divided by the rated field voltage. This
39、rate, if maintained constant (curve ac), would develop the same voltage-time area as obtained from the response (curve ab) over the first half-second interval (unless a different time interval is specified). NOTE 1 Refer to Figure 2. NOTE 2 The excitation system nominal response shall be determined
40、with the excitation system voltage initially equal to the rated field voltage of the synchronous machine, after which the excitation system ceiling voltage is rapidly attained by introducing a specified voltage error step. NOTE 3 The excitation system nominal response shall be determined with the ex
41、citation system loaded with a resistance equal to the field resistance under rated load conditions and adequate inductance so that voltage drop effects and current and voltage waveforms are reasonably duplicated. NOTE 4 For excitation systems whose supply depends on the synchronous machine voltage a
42、nd (if applicable) current, the nature of the power system disturbance and specific design parameters of the excitation system and the synchronous machine influence the excitation system output. For such systems, the excitation system nominal response shall be determined considering a specified supp
43、ly voltage (usually rated voltage) and (if applicable) synchronous machine current. NOTE 5 If, for practical considerations, tests can only be made on individual components or the entire excitation system but only at partial or no-load, analytical methods may be used to predict performance with rate
44、d field voltage (see NOTE 1). NOTE 6 For excitation systems employing a rotating exciter, the excitation system nominal response shall be determined at rated speed. NOTE 7 Not normally used in the specification of static excitation systems. There is a potential conflict if ceiling voltage is also sp
45、ecified. cbdeoaNominal Response =ce - ao(ao)(oe)where:oe = 0.5 secondsao = synchronous machinerated field voltageSecondsExciter VoltageExcitation system nominal response IEEE Std 421.1-2007 IEEE Standard Definitions for Excitation Systems for Synchronous Machines 6 Copyright 2007 IEEE. All rights re
46、served. 3.30 excitation system output terminals: The place of output from the equipment comprising the excitation system. These terminals may be identical with the field winding terminals. 3.31 excitation system rated current: The direct current at the excitation system output terminals that the exc
47、itation system can supply under defined conditions of its operation. This current is at least that value required by the synchronous machine under the most demanding continuous operating conditions (generally resulting from synchronous machine voltage, frequency, and power factor variations). 3.32 e
48、xcitation system rated voltage: The direct voltage at the excitation system output terminals that the excitation system can provide when delivering excitation system rated current under rated continuous load conditions of the synchronous machine with its field winding at 1) 75 C for field windings d
49、esigned to operate at rating with a temperature rise of 60 C or less; or 2) 100 C for field windings designed to operate at rating with a temperature rise greater than 60 C. 3.33 excitation system stabilizer: A function that serves to modify the voltage regulator forward signal by either series or feedback compensation to improve the dynamic performance of the excitation control system. 3.34 excitation system voltage response time: The time in seconds for the excitation vo
