1、IEEE Std 946-2004(Revision of IEEE Std 946-1992)946TMIEEE Recommended Practice for theDesign of DC Auxiliary PowerSystems for Generating Stations3 Park Avenue, New York, NY 10016-5997, USAIEEE Power Engineering SocietySponsored by theEnergy Development and Power Generation Committee8 June 2005Print:
2、 SH95307PDF: SS95307The Institute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USACopyright 2005 by the Institute of Electrical and Electronics Engineers, Inc.All rights reserved. Published 8 June 2005. Printed in the United States of America.IEEE is a registe
3、red trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educationalclassroom use can also be obtained through the Copyright Clearance Center.NOTEAttention is called to the possibility that implementation of this standard may require use of su
4、bjectmatter covered by patent rights. By publication of this standard, no position is taken with respect to the exist-ence or validity of any patent rights in connection therewith. The IEEE shall not be responsible for identifyingpatents for which a license may be required by an IEEE standard or for
5、 conducting inquiries into the legal valid-ity or scope of those patents that are brought to its attention.IntroductionDC auxiliary power systems continue to play a vital role in generating station control and in providingbackup for emergencies. This recommended practice fulfils a need within the in
6、dustry to provide commonor standard practices for the design of dc systems. The design features are applicable to all installations andsystems capacities.The original issue of IEEE Std 946 was published in 1985 with the title IEEE Recommended Practice for theDesign of Safety-Related DC Auxiliary Pow
7、er Systems for Nuclear Power Generating Stations. The 1992revision changed the title to apply to all generating stations, while including specific guidance and a detailedbibliography of nuclear design reference standards. This revision makes a general update to reflect the mostrecent industry practi
8、ces as well as substantial additions to annexes. In addition, as the design of nuclearplant systems has become well documented by other IEEE standards, the direct emphasis on unique aspectsof nuclear plant design has been further diminished, with a full listing of the nuclear design standardsinclude
9、d in Annex A. Some nuclear discussion and illustrative figures have been retained as they offer aconstructive comparison to non-nuclear designs without having to resort to additional standards.This recommended practice was prepared by a Working Group that is part of the Station Design, Operation,and
10、 Control Subcommittee and was sponsored by the Energy Development and Power GenerationCommittee of the IEEE Power Engineering Society.Notice to usersErrataErrata, if any, for this and all other standards can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/updates/errata/index
11、.html. Users are encouraged to check this URL forerrata periodically.InterpretationsCurrent interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/index.html.PatentsAttention is called to the possibility that implementation of this standard may require use
12、 of subject mattercovered by patent rights. By publication of this standard, no position is taken with respect to the existence orvalidity of any patent rights in connection therewith. The IEEE shall not be responsible for identifyingpatents or patent applications for which a license may be required
13、 to implement an IEEE standard or forconducting inquiries into the legal validity or scope of those patents that are brought to its attention.This introduction in not part of IEEE Std 946-2004, IEEE Recommended Practice for the Design of DC AuxiliaryPower Systems for Generating Stations.Copyright 20
14、05 IEEE. All rights reserved.iiiParticipantsAt the time this standard was completed, the Task Force on DC Auxiliary Power Working Group had thefollowing membership. Joseph Jancauskas, ChairThe following members of the individual balloting committee voted on this standard. Balloters may havevoted for
15、 approval, disapproval, or abstention. When the IEEE-SA Standards Board approved this standard on 8 December 2004, it had the followingmembership:Don Wright, ChairSteve M. Mills, Vice ChairJudith Gorman, Secretary*Member EmeritusAlso included are the following nonvoting IEEE-SA Standards Board liais
16、ons:Satish K. Aggarwal, NRC RepresentativeRichard DeBlasio, DOE RepresentativeAlan Cookson, NIST RepresentativeJennie SteinhagenIEEE Standards Project EditorRobert BeaversJohn K. CoylePaul Hellen Jim LogothetisKurt UlhirWilliam AckermanMark BowmanSteven BrockschinkTommy CooperJohn K. CoyleGary Engma
17、nnRobert FentonPatrick GoveRandall GrovesEdward Horgan, Jr.Richard HuberDavid JacksonJoseph Jancauskas Lawrence LongGregory LuriKeith MalmedalJohn MerandoPaul PillitteriJames RuggieriMalcolm ThadenShanmugan ThamilarasanGerald VaughnZhenxue XuChuck AdamsStephen BergerMark D. BowmanJoseph A. BruderBob
18、 DavisRoberto de Marca BoissonJulian Forster*Arnold M. GreenspanMark S. HalpinRaymond HapemanRichard J. HollemanRichard H. HulettLowell G. JohnsonJoseph L. Koepfinger*Hermann KochThomas J. McGeanDaleep C. MohlaPaul NikolichT. W. OlsenRonald C. PetersenGary S. RobinsonFrank StoneMalcolm V. ThadenDoug
19、 ToppingJoe D. WatsonCopyright 2005 IEEE. All rights reserved.ivContents 1. Overview 1 1.1 Scope . 1 2. Normative references 1 3. Definitions 2 4. General . 2 4.1 Description and operation 2 4.2 Number of batteries . 3 4.3 Number of chargers and distribution panels 3 4.4 System voltage and battery s
20、ize considerations. 3 4.5 Physical layout. 4 5. Batteries 4 5.1 General description 4 5.2 Determination of battery duty cycles and battery size (capacity) 4 5.3 Installation design 5 5.4 Maintenance, testing, and replacement 5 5.5 Qualification 5 6. Battery chargers 5 6.1 General description 5 6.2 D
21、etermination of rated output 5 6.3 Sample calculations . 6 6.4 Installation Design. 6 6.5 Output characteristics 7 7. Distribution system and equipment 7 7.1 Protective device description and rating 7 7.2 Typical diagram. 8 7.3 Voltage ratings for dc powered components . 8 7.4 Instrumentation, contr
22、ols, and alarms 12 7.5 Special dc loads . 14 7.6 Design features to assist in battery testing. 16 7.7 Cross-tie between buses. 16 7.8 Qualification 17 7.9 Available short-circuit current. 17 8. Spare equipment . 18 v Copyright 2005 IEEE. All rights reserved. Annex A (informative) Bibliography . 19 A
23、nnex B (informative) Battery charger ratingsample calculations 21 B.1 Introduction. 21 B.2 Formulas . 21 B.3 Sample calculations 22 Annex C (informative) Batteries, available short-circuit currentsample calculations 23 C.1 Introduction. 23 C.2 Discussion. 23 C.3 Sample calculations 24 Annex D (infor
24、mative) Effect of grounds on the operation of dc auxiliary power systems . 27 D.1 Introduction 27 D.2 Discussion. 27 D.3 Sample evaluations . 27 Annex E (informative) Battery charger, short-circuit current contribution 30 E.1 Abstract . 30 E.2 Discussion . 30 E.3 Sample evaluation . 31 vi Copyright
25、2005 IEEE. All rights reserved. IEEE Recommended Practice for the Design of DC Auxiliary Power Systems for Generating Stations 1. 1.12. Overview Scope This recommended practice provides guidance for the design of the dc auxiliary power systems for nuclear and non-nuclear power generating stations. T
26、he components of the dc auxiliary power system addressed by this recommended practice include lead-acid storage batteries, static battery chargers, and distribution equipment. Guidance for selecting the quantity and types of equipment, the equipment ratings, interconnections, instrumentation, contro
27、l, and protection is also provided. The ac power supply to the battery chargers; the loads served by the dc systems, except as they influence the dc system design; and dedicated engine starting (cranking) battery systems are beyond the scope of this recommended practice. Normative references The fol
28、lowing referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments or corrigenda) applies. IEEE Std 484, IEEE Recommended Practice fo
29、r Installation Design and Installation of Vented Lead-Acid Storage Batteries for Stationary Applications.1,2IEEE Std 485, IEEE Recommended Practice for Sizing Large Lead Storage Batteries for Generating Stations and Substations. IEEE Std 649, IEEE Standard for Qualifying Class 1E Motor Control Cente
30、rs for Nuclear Power Generating Stations. IEEE Std 666, IEEE Design Guide for Electric Power Service Systems for Generating Stations. 1 IEEE publications are available from the Institute of Electrical and Electronics Engineers, Inc., 445 Hoes Lane, Piscataway, NJ 08854, USA (http:/standards.ieee.org
31、/). 2 The IEEE standards or products referred to in this clause are trademarks of the Institute of Electrical and Electronics Engineers, Inc. 1 Copyright 2005 IEEE. All rights reserved. IEEE Std 946-2004 IEEE Recommended Practice for the Design of DC Auxiliary Power Systems for Generating Stations I
32、EEE Std 1115, IEEE Recommended Practice for Sizing Nickel-Cadmium Batteries for Stationary Applications. IEEE Std 1184, IEEE Guide for the Selection and Sizing of Batteries for Uninterruptible Power Systems. IEEE Std 1187, IEEE Recommended Practice for Installation Design and Installation of Valve-R
33、egulated Lead-Acid Storage Batteries for Stationary Applications. IEEE Std 1189 IEEE Guide for Selection of Valve-Regulated Lead-Acid (VRLA) Batteries for Stationary Applications. IEEE Std 1375, IEEE Guide for the Protection of Stationary Battery Systems. 3.4.4.1Definitions For the purposes of this
34、recommended practice, the following terms and definitions apply. The Authoritative Dictionary of IEEE Standards B23, should be referenced for terms not defined in this clause. 3.1 battery capacity: The amp-hours available in an installed battery as measured by test. This is measured, normally after
35、an equalize charge, by a performance or modified performance test. The battery capacity may be larger or smaller than the rated capacity and is expressed as a per cent of rated capacity for a given duration. For lead acid batteries, this is due to degradation of the grid, connections, welds, pellet
36、interface to the grid, crystal surface contact interface of the lead oxides, wet surface interface between the lead oxide and the electrolyte, electrolyte specific gravity, and transport resistance of the hydrogen and oxygen between the positive and negative plates. Since the factors which affect ba
37、ttery performance are varied, the measured battery capacity at a long duration may differ from the measured capacity at a short duration. 3.2 battery rated capacity: The rated amp-hours available in a battery at 100% charge. This is established via “S” or fan curves by a manufacturers test of a limi
38、ted sample of cells using the interconnecting hardware supplied with the standard installation. The rated amp-hours may differ as a function of the discharge duration, long duration discharges typically utilizes the available material more effectively. NOTESee IEEE Std 485 for an example of the manu
39、facturers sizing curves.43.3 battery state of charge: A factor between 0 and 100. It establishes the available amp-hours by multiplying the state of charge times the battery capacity times the battery rated capacity for a specified discharge duration. The battery state of charge reflects the convers
40、ion or restoration of lead sulfate to lead oxide after a discharge. General Description and operation All power generating stations require dc auxiliary power systems to operate those dc components that must be available should a loss of ac power occur. Some examples of such components are auxiliary
41、 motors, circuit breakers, relays, solenoids, and inverters. The dc source(s) may be one common battery for both power and control or two separate batteries; one for power and another for control and instrumentation. Separate batteries are recommended for special services such as for engine (crankin
42、g) starting. 3 The numbers in brackets correspond to those of the bibliography in Annex A. 4 Notes in text, tables, and figures are given for information only and do not contain requirements needed to implement this standard. 2 Copyright 2005 IEEE. All rights reserved. IEEE Std 946-2004 IEEE Recomme
43、nded Practice for the Design of DC Auxiliary Power Systems for Generating Stations In normal operation, the battery and charger(s) are both connected to the dc distribution bus and, therefore, operate as parallel sources to supply the connected loads. The charger, in addition to charging the battery
44、, carries the normal continuous load. Chargers are typically provided with a current limiting circuit for overload protection. If overloaded, the charger output voltage will drop, causing all loads in excess of the charger rating to be supplied by the battery. In the event of: a) a failure of the ac
45、 power supply to the charger(s) or b) a charger failure (or the removal of the charger from service), the battery must supply all of the power required by the loads for some designed period of time. Specific design guidance for dc systems for nuclear generating stations are discussed fully in numero
46、us design standards found in Annex A. 4.24.34.4Number of batteries As a minimum, one battery should be provided for each unit. If the auxiliary loads of one unit are divided into two or more independent systems, then each independent system should be provided with a separate battery. If the maximum
47、dc power requirements exceed the capacity of one battery, then the development of two independent systems should be considered. Cross-ties from other batteries may be provided, where appropriate (see 7.7). For Class 1E nuclear applications, as a minimum, a separate battery shall be provided for each
48、 Engineered Safety Feature (ESF) Division in each unit in order to provide the required independence between redundant Class 1E power systems. For increased operating flexibility in designs where the reactor protection system channels are dependent on dc, the number of safety-related batteries provi
49、ded on each unit should equal the number of independent and redundant reactor protection system (instrumentation and control) channels. For example, in a unit with four reactor protection channels, four batteries should be provided. The rated capacity of each battery should be determined as described in 5.2 of this guide. Number of chargers and distribution panels As a minimum, one battery charger and main distribution panel should be provided for each battery. Additional (spare or standby) chargers should be considered for increased operating fle
