1、IEEE Std C37.93-2004(Revision ofIEEE Std C37.93-1987)IEEE StandardsC37.93TMIEEE Guide for Power SystemProtective Relay Applications of AudioTones Over Voice Grade Channels3 Park Avenue, New York, NY 10016-5997, USAIEEE Power Engineering SocietySponsored by thePower System Relaying CommitteeIEEE Stan
2、dards16 August 2004Print: SH95228PDF: SS95228The Institute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USACopyright 2004 by the Institute of Electrical and Electronics Engineers, Inc.All rights reserved. Published 16 August 2004. Printed in the United States
3、of America.IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions ofany individual standard for educational classroom use can also be obtained through the Copyright ClearanceCenter.Copyright 2004 IEEE. All rights reserved. iiiIntroduction(This introductio
4、n is not part of IEEE Std C37.93-2004, IEEE Guide for Power System Protective Relay Applications ofAudio Tones Over Voice Grade Channels.)This guide, which was last revised in 1987, recognized the reliability demands placed on audio-tone relayingequipment and the associated telephone facilities. The
5、 challenges for providing reliable (secure anddependable), high-speed pilot protection have increased enormously over the years. These challenges haveoccurred as power systems are operated closer to design limits due to economic, environmental, andregulatory considerations.This revision, IEEE Std C3
6、7.93-2004, retains the original intent of providing a reference for manufacturers,designers, and users of audio-tone equipment and for providers of the telecommunication channelsemployed with the audio-tone protective relay schemes. It was prepared not only for those using an audio-tone relay system
7、 for the first time, but also as a reference for the experienced user.IEEE Std C37.93-2004 includes more information on utility-owned telecommunications equipment than theprevious revision. More multiplexing equipment is being used by the utilities for digital transmission overfiber and microwave. T
8、his revision has more detailed information regarding these types of systems. Noisecharacteristics of digital systems are different from analog, and their effect is covered in this revision.This guide provides a basic introduction and description of leased telephone channels. Also included aretypical
9、 interface requirements and the transmission line characteristics of three channel offerings, along withexamples. Since other IEEE standards cover the subject of protection more comprehensively, a briefdescription of special protection devices is provided for informational purposes. Clauses have bee
10、n revisedto be consistent with current telephone company practices, and the subclause concerning periodicmaintenance has been expanded.Acknowledgments This revision was prepared by the Audio Tone Guide Working Group of the Relaying ChannelsSubcommittee, Power Systems Relaying Committee of the IEEE P
11、ower Engineering Society. The review bythe Power Systems Communication Committee of the IEEE Power Engineering Society and theTransmission Systems Committee of the IEEE Communication Society are greatly appreciated. TheWorking Group is indebted to its members, past and present, who as members of the
12、 Power SystemRelaying Committee and other liaison Committees and Groups, contributed their experience and knowledge. PatentsAttention is called to the possibility that implementation of this standard may require use of subject mattercovered by patent rights. By publication of this standard, no posit
13、ion 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 by to implement an IEEE standard or forconducting inquiries into the legal validity
14、or scope of those patents that are brought to its attention.iv Copyright 2004 IEEE. All rights reserved.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.html. Users are encouraged to
15、 check this URL forerrata periodically.InterpretationsCurrent interpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/index.html.ParticipantsAt the time this guide was completed, the Audio Tone Guide Working Group had the followingmembership:William Higinbo
16、tham, ChairJerry Hohn, Vice ChairThe following members of the individual balloting committee voted on this guide. Balloters may have votedfor approval, disapproval, or abstention. Doug DawsonKenneth FoderoJeff GilbertJohn HorwathChris HuntleyTim PhillippeRoger Ray Mark SimonVeseun SkendzicD. Wardlow
17、William AckermanSteve AlexandersonGeorge BartokKenneth BehrendtStuart BoucheyGustavo BrunelloTerry BurnsRonald DaubertPaul DrumGary EngmannKenneth FoderoWilliam HiginbothamJerry HohnEdward Horgan, Jr.James D. Huddleston, IIIChris HuntleyJames InglesonDavid JacksonJoseph L. KoepfingerWilliam LoweGreg
18、ory LuriJesus MartinezJeff McElrayGary MichelBrian MugalianAnthony NapikoskiRoger RayCharles RogersJames RuggieriMohindar S. SachdevTony SeegersMark SimonJames TeagueJohn T. TengdinDemetrios TziouvarasPhilip WinstonZhenxue XuCopyright 2004 IEEE. All rights reserved. vWhen the IEEE-SA Standards Board
19、 approved this guide on 25 March 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 liaisons:Satish K. Aggarwal, NRC RepresentativeRichard DeBlasio, DOE Representati
20、veAlan Cookson, NIST RepresentativeSavoula AmanatidisIEEE Standards Managing EditorChuck AdamsH. Stephen BergerMark D. BowmanJoseph A. BruderBob DavisRoberto de BoissonJulian Forster*Arnold M. GreenspanMark S. HalpinRaymond HapemanRichard J. HollemanRichard H. HulettLowell G. JohnsonJoseph L. Koepfi
21、nger*Hermann KochThomas J. McGeanDaleep C. MohlaPaul NikolichT. W. OlsenRonald C. PetersenGary S. RobinsonFrank StoneMalcolm V. ThadenDoug ToppingJoe D. Watsonvi Copyright 2004 IEEE. All rights reserved.Contents1. Overview 11.1 Scope 11.2 Purpose. 12. References 13. Transmitting and receiving equipm
22、ent 23.1 Relaying requirements . 23.2 Basic types of audio-tone systems . 33.3 Power supplies . 43.4 Equipment protection from surge phenomena. 43.5 Tone level meter 53.6 Frequency translation protection . 54. Voice grade channels . 64.1 Introduction 64.2 Need for joint discussions 64.3 Characterist
23、ics of voice grade channels. 74.4 Private networks 175. Application principals 185.1 Audio-tone relaying systems . 185.2 Mode of operation 235.3 Signal and channel arrangements 235.4 Signal transmission 305.5 Operating time of the system . 315.6 Noise and noise suppression 326. Installation and test
24、ing . 356.1 Installation considerations . 356.2 Testing . 366.3 Periodic maintenance. 37Annex A (informative) Bibliography 38Annex B (informative) Example of audio-tone circuit considerations 39Annex C (informative) Signal level measurements and terms 41Copyright 2004 IEEE. All rights reserved. 1IEE
25、E Guide for Power System Protective Relay Applications of Audio Tones Over Voice Grade Channels1. Overview1.1 ScopeThis guide contains information and recommendations for applying audio tones over voice grade channelsfor power system relaying, including transmitting and receiving equipment, leased v
26、oice grade channels,application principles, installation, and testing. Reflected in this guide is the knowledge and experience ofequipment manufacturers and telephone companies as well as that of power utility users.This guide is not intended to supplant specific or general instructions contained in
27、 the manufacturersinstruction books or in any contractual agreement between a manufacturer or telephone company(s) or bothand a purchaser of a given relaying system. The figures in 4.3 are used for illustrative purposes only and donot represent the preferred protection under all conditions.1.2 Purpo
28、seThe primary purpose of this document is to guide the power system user in applying, installing, andoperating audio-tone protective relaying systems over voice grade channels. Secondly, it is to provide areference for equipment manufacturers engaged in the design and application of relaying equipme
29、nt and fortelephone personnel engaged in providing telecommunications channels for audio-tone protective relayschemes. The guide has been prepared not only for those considering audio-tone relaying for the first time,but as a reference for the experienced.2. ReferencesThis guide shall be used in con
30、junction with the following standards. When the following standards aresuperseded by an approved revision, the revision shall apply.IEEEStd C37.93-2004 IEEE GUIDE FOR POWER SYSTEM PROTECTIVE RELAY APPLICATIONS2 Copyright 2004 IEEE. All rights reserved.IEEE Std 367-1996 (Reaff 2002), IEEE Recommended
31、 Practice for Determining the Electric Power Sta-tion Ground Potential Rise and Induced Voltage from a Power Fault.1,2IEEE Std 487-2000, IEEE Recommended Practice for the Protection of Wire-Line Communication Facili-ties Serving Electric Supply Locations.IEEE Std C37.90-1989 (Reaff 1994), IEEE Stand
32、ard Relays and Relay Systems Associated with ElectricPower Apparatus.IEEE Std C37.90.1-2002, IEEE Standard for Surge Withstand Capability (SWC) Tests for Relays andRelay Systems Associated with Electric Power Apparatus. IEEE Std C37.90.2-1995 (Reaff 2001), IEEE Standard for Withstand Capability of R
33、elay Systems to Radi-ated Electromagnetic Interference from Transceivers.3. Transmitting and receiving equipment3.1 Relaying requirements3.1.1 Receiver response Receiver response is essential in ensuring correct operation of an audio-tone relay scheme. It is mostimportant that receivers be capable o
34、f discriminating between valid signals and spurious signals which maybe introduced into the voice-grade audio channels particularly during power system disturbances3.1.2 Security/dependability/speedThe three characteristicssecurity, dependability, and speedcomprise the core requirements of anytelepr
35、otection system. Security, the assurance that false tripping will not occur, can be highly desired insome applications. In applications like direct transfer tripping, false trips can have disastrous effects. Otherapplications, like unblocking, favor dependability, the assurance that valid tripping w
36、ill occur, because theeffect of missing a trip is more serious. Speed, or trip time, can be the ultimate requirement in otherapplications. Each application must be examined because it is difficult, or often impossible, to improvesecurity, dependability, or speed without adversely affecting the other
37、 characteristics. 3.1.3 General requirementsEquipment designed for relaying functions and for use with available types of voice-grade audiocommunication circuits should meet the following requirements:The operate time should be consistent with the relay application requirements, but in the interest
38、of security,the tone operate time should not be any faster than necessary, typically 1016 ms. This includes tonetransmitter operation time (after being keyed), tone receiver response time, and operate time of an outputdevice. This does not include voice-grade audio channel delay time, which may vary
39、 from a fewmilliseconds to more than 10 ms. Accordingly, in writing audio-tone terminal equipment specifications, theuser should exclude voice grade-audio channel delay time when specifying required speed, since this time isnot under the control of the tone equipment manufacturer. 1The IEEE standard
40、s or products referred to in this clause are trademarks of the Institute of Electrical and Electronics Engineers, Inc.2IEEE publications are available from the Institute of Electrical and Electronics Engineers, Inc., 445 Hoes Lane, Piscataway, NJ 08854,USA (http:/standards.ieee.org/).IEEEOF AUDIO TO
41、NES OVER VOICE GRADE CHANNELS Std C37.93-2004Copyright 2004 IEEE. All rights reserved. 3The highest possible security for the following conditions should be considered:a) Steady-state noise equal in magnitude to the signal over the voice frequency bandwidthb) Failure of the monitoring signalc) Inter
42、mittent shorting, opening, or grounding of the communication circuitd) Complete interruption of the communication circuite) Crosstalk from an adjacent circuitf) Inadvertent application of test signals normally encountered in channel testingg) Power system disturbancesh) Removal and application of po
43、wer supplyi) Multiplex or carrier frequency translationsj) Single component failurek) Voltage transients in power supply and output circuitsl) Electromagnetic interference (EMI) and radio frequency interference (RFI) effectsm) Physical substation environment3.2 Basic types of audio-tone systems3.2.1
44、 GeneralThe equipment to meet the relaying requirements may take any of several forms. The importance of thefunction requires that the user be assured of a workable system on a continuous basis with an alarm toindicate an inoperative condition. Each type of equipment has both advantages and disadvan
45、tages.3.2.2 Frequency shift modulated equipmentThis equipment is the type most frequently used. A signal is always present under normal conditions on oneof two possible frequencies, guard or trip. Frequency shift equipment is inherently self-monitoring when thedesign is such that the same components
46、 generate, amplify, and receive both frequencies. Some frequencyshift equipment also employs an enhanced trip signal so that the signal-to-noise ratio (SNR) is improved atthe time of trip signal transmission (see 4.3.2.1). This increase in signal power during enhanced signalingtrip typically lasts f
47、or 50100 ms.3.2.3 ON-OFF modulated equipmentON-OFF equipment is not inherently self-monitoring because many components are inactive in theirquiescent state. If the scheme utilizes more than one tone signal, the circuit can be designed for periodic in-service testing. This type of equipment is presen
48、tly applicable only to blocking type relaying systems.3.2.4 Coded pulse signaling Coded pulse signaling is another mode of signal applicable to relay functions employing frequency shift orON-OFF modulation for signal transmission. The signal is keyed in a time sequence to form a codecomposed of mark
49、s and spaces.Coded pulse equipment appears to offer great security against false operation due to interference. Codedpulse systems require greater channel bandwidths for the same operating speed than do the basic frequencyshift or ON-OFF systems. This factor should be considered in view of the frequency range of the voice-grade audio channel and the overall function of the equipment.IEEEStd C37.93-2004 IEEE GUIDE FOR POWER SYSTEM PROTECTIVE RELAY APPLICATIONS4 Copyright 2004 IEEE. All rights reserved.3.2.5 Phase-shift keying modulated equipmentThe form of phase
