1、 IEEE Guide for TemperatureMonitoring of Cable Systems Sponsored by the Insulated Conductors Committee IEEE 3 Park Avenue New York, NY 10016-5997 USA 8 June 2012 IEEE Power +1 978 750 8400. Permission to photocopy portions of any individual standard for educational classroom use can also be obtained
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14、ights, and the risk of infringement of such rights, is entirely their own responsibility. Further information may be obtained from the IEEE Standards Association. vi Copyright 2012 IEEE. All rights reserved. Participants At the time this guide was submitted to the IEEE-SA Standards Board for approva
15、l, the Temperature Monitoring of Cable Systems Working Group had the following membership: Mohamed Chaaban, Chair Chris Grodzinski, Vice Chair Pierre A. Argaut Earle C. Bascom III William Black Jean-Marie Braun Sudhakar Cherukupalli John H. Cooper John Downes Anthony Ernst Dennis Johnson Mohammad Pa
16、sha Dave Purnhagen Jay A. Williams The following members of the individual balloting committee voted on this guide. Balloters may have voted for approval, disapproval, or abstention. William J. Ackerman Earle C. Bascom III Michael Bayer Robert Beavers Kenneth Bow Kent Brown Nissen Burstein William B
17、yrd Mohamed Chaaban Robert Christman John Densley Carlo Donati Gary Donner Gary Engmann Marcel Fortin David Gilmer Todd Goyette Steven Graham Chris Grodzinski Randall Groves Edward Gulski Ajit Gwal Richard Harp Jeffrey Hartenberger Timothy Hayden Lee Herron Lauri Hiivala Werner Hoelzl David Horvath
18、A. S. Jones Gael Kennedy Chad Kiger Robert Konnik Jim Kulchisky Chung-Yiu Lam Benjamin Lanz Gerald Liskom Greg Luri Gary Michel Jerry Murphy Michael S. Newman Lorraine Padden Robert Resuali Michael Roberts Bartien Sayogo Dennis Schlender Gil Shultz Michael Smalley James Smith Jerry Smith Gary Stoedt
19、er David Tepen Peter Tirinzoni John Vergis Yingli Wen Dawn Zhao Tiebin Zhao When the IEEE-SA Standards Board approved this standard on 29 March 2012, it had the following membership: Richard H. Hulett, Chair John Kulick, Vice Chair Robert Grow, Past Chair Judith Gorman, Secretary Satish Aggarwal Mas
20、ayuki Ariyoshi Peter Balma William Bartley Ted Burse Clint Chaplin Wael Diab Jean-Philippe Faure Alexander Gelman Paul Houz Jim Hughes Young Kyun Kim Joseph L. Koepfinger* David J. Law Thomas Lee Hung Ling Oleg Logvinov Ted Olsen Gary Robinson Jon Walter Rosdahl Mike Seavey Yatin Trivedi Phil Winsto
21、n Yu Yuan *Member Emeritus vii Copyright 2012 IEEE. All rights reserved. Also included are the following nonvoting IEEE-SA Standards Board liaisons: Richard DeBlasio, DOE Representative Michael Janezic, NIST Representative Don Messina IEEE Standards Program Manager, Document Development Erin Spiewak
22、 IEEE Standards Program Manager, Technical Program Development viii Copyright 2012 IEEE. All rights reserved. Introduction This introduction is not part of IEEE Std 1718-2012, IEEE Guide for Temperature Monitoring of Cable Systems. Temperature is one of the most important physical data to be monitor
23、ed for real-time rating of underground cables. In fact, the cable conductor temperature should be known, with reasonable accuracy, at any moment in order to calculate the projected maximum current-carrying capacity, given the operating and ambient conditions. The best and most accurate thermal ratin
24、g is based on direct monitoring of the conductor temperature under load, although for practical reasons, this is difficult to do when the cable is energized. This process would eliminate any uncertainties related to the correlation between the measured temperature, if it is not that of the conductor
25、, and the conductor temperature itself. In the case of solid dielectric cables, the sensors (fiber optics) could be placed closer to the conductors, thus, permitting easier and accurate modeling of the conductor temperatures. Pipe-type cable systems, in contrast, need fibers to be installed on the p
26、ipe surface for proper thermal modeling. Underground cable ratings have traditionally been calculated using conservative assumptions about the environment and installation configurations to limit the likelihood that the cables will exceed normal operating temperature during typical load cycling. Tra
27、ditional rating techniques are based on the classic 1957 paper by Neher and McGrath B36,aand more recently on IEC 60287-1993 B21 and IEC 60853-1989 B22. Utility engineers are increasingly trying to get more power through existing lines, including underground cables, resulting in utilities considerin
28、g the use of uprating and dynamic ratings. This guide is intended to help electrical engineers and power managers to understand more completely the temperature monitoring technology and its application to underground power cable systems. aThe numbers in brackets correspond to those of the bibliograp
29、hy in Annex A. ix Copyright 2012 IEEE. All rights reserved. Contents 1. Overview 1 1.1 Scope . 1 1.2 Purpose 1 2. Definitions 2 3. Discrete temperature monitoring system 3 3.1 Thermocouples 3 3.2 Resistance temperature detectors (RTDs) 5 3.3 Thermistors 5 3.4 Optical sensors . 6 4. Distributed tempe
30、rature sensing system (DTS) 6 4.1 Optical fiber . 6 4.2 Optical-electrical processing unit 8 4.3 Controller . 8 4.4 Performance and limitations of the DTS . 8 5. Other issues related to the temperature monitoring .10 5.1 Location of the temperature sensors .10 5.2 Performance, reliability, and maint
31、enance 11 5.3 Fiber testing 12 5.4 General precautions in temperature monitoring13 6. User interface 14 6.1 Introduction 14 6.2 Types of interfaces 14 6.3 Types of real-time rating systems .15 7. Data communication 15 7.1 Introduction 15 7.2 Software 16 7.3 Hardware 16 Annex A (informative) Bibliogr
32、aphy 18 Annex B (informative) Typical acceptance criteria for a fiber optic circuit intended to be used temperature sensor .21 Annex C (informative) Additional mechanical testing for cables with integrated fiber 22 1 Copyright 2012 IEEE. All rights reserved. IEEE Guide for Temperature Monitoring of
33、Cable Systems IMPORTANT NOTICE: IEEE Standards documents are not intended to ensure safety, health, or environmental protection, or ensure against interference with or from other devices or networks. Implementers of IEEE Standards documents are responsible for determining and complying with all appr
34、opriate safety, security, environmental, health, and interference protection practices and all applicable laws and regulations. This IEEE document is made available for use subject to important notices and legal disclaimers. These notices and disclaimers appear in all publications containing this do
35、cument and may be found under the heading “Important Notice” or “Important Notices and Disclaimers Concerning IEEE Documents.” They can also be obtained on request from IEEE or viewed at http:/standards.ieee.org/IPR/disclaimers.html. 1. Overview This guide is applicable to the temperature monitoring
36、 of solid dielectric such as crosslinked polyethylene (XLPE) or ethylene propylene rubber (EPR), self-contained, and pipe-type cable systems. The ampacity limits of these systems are based on the maximum allowable temperature of the insulation. Typical ampacity limits are normally based on generaliz
37、ed and assumed worst expected conditions. A temperature monitoring system, appropriately applied, provides real-time temperature information to the user that will permit adjusting the current limits for both continuous and emergency conditions. 1.1 Scope This guide presents an overview of the existi
38、ng and emerging temperature monitoring systems related to power cable installations. It summarizes the features, benefits, and limitations of both discrete and distributed temperature monitoring for cable ratings. This guide addresses the various aspects of user-interface and data communication issu
39、es needed to make the system more effective and more user- friendly. 1.2 Purpose The purpose of this guide is to assist users in applying offline or real-time temperature monitoring of power cable systems by addressing the following major issues: a) Type of cable system installation: existing or new
40、. b) Circuit length, type of terrain, and backfill along the cable route that may favor the use of distributed rather than discrete temperature measurement or vice versa. IEEE Std 1718-2012 IEEE Guide for Temperature Monitoring of Cable Systems 2 Copyright 2012 IEEE. All rights reserved. c) Advantag
41、es/disadvantages of using a real-time monitoring versus offline monitoring system. d) System complexity, performance, reliability, and maintenance. e) Recommended design, operating criteria, and data transfer. f) Influence of adjacent circuits. 2. Definitions For the purposes of this document, the f
42、ollowing terms and definitions apply. The IEEE Standards Dictionary: Glossary of Terms this is to avoid errors in temperature measurements. 3.2 Resistance temperature detectors (RTDs) These temperature sensors are made of fine wires or thin film metallic elements whose resistance increases with temp
43、erature. A small current (alternating current ac or dc) is circulated through the sensor and its resistance is measured. The temperature of the sensors is then deduced using available tables or calibration equations specific to the type of RTD used. Unlike a thermocouple, an RTD is not self-powered.
44、 The fact that a current must be passed through causes Joule (I2R) heating within the RTD. This self-heating could corrupt the measurement and lead to errors. RTDs are somewhat more fragile than thermocouples. They are, however, more precise and more stable. In the field of cable temperature monitor
45、ing, these characteristics typically do not procure any substantial advantages over thermocouples. The reason is that a temperature resolution of more than 1 C is rarely needed, which is a level of precision well within the reach of any type of thermocouples. Due to their fragility, RTDs are usually
46、 encased in steel tubing or potted in epoxy. They are prone to vibration-induced damage, and so adequate care should be taken when installing these devices. The additional protection makes them less suitable to record transient events due to their increased time constant. Similar peripheral equipmen
47、t is used to condition the signal like in the case of thermocouples, with the addition of an external power source to inject the necessary current through the RTD. 3.3 Thermistors Thermistors are temperature-sensitive resistors made from semiconductors or metallic oxides, whose resistance varies inv
48、ersely with temperature in a highly nonlinear manner. They are used frequently where high accuracy is required (up to 0.001 C). This is far too precise for cable monitoring needs. They also require an external power source and some form of mechanical protection. They must be mounted carefully to avo
49、id crushing or bond separation. Peripheral equipment identical to the RTDs is used to condition the signal and to evaluate the corresponding temperature. IEEE Std 1718-2012 IEEE Guide for Temperature Monitoring of Cable Systems 6 Copyright 2012 IEEE. All rights reserved. 3.4 Optical sensors These types of sensors are popular for temperature measurement in places where a harsh environment with high electromagnetic interference (EMI) and radio-frequency interference (RFI) exist. They could also be used to monitor temperature under voltage. They are classi
