1、 International Telecommunication Union ITU-T K.78TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (06/2009) SERIES K: PROTECTION AGAINST INTERFERENCE High altitude electromagnetic pulse immunity guide for telecommunication centres Recommendation ITU-T K.78 Rec. ITU-T K.78 (06/2009) i Recommendation I
2、TU-T K.78 High altitude electromagnetic pulse immunity guide for telecommunication centres Summary Recommendation ITU-T K.78 specifies the radiated and conducted immunity requirements against a high altitude electromagnetic pulse (HEMP) for equipment installed in telecommunication centres for functi
3、ons such as switching, transmission, radiocommunication, and power distribution. The requirements consist of immunity test methods and levels for telecommunication equipment in each installation condition. Immunity levels can be improved by applying a protection concept of surge protective devices (
4、SPDs) for surge mitigation and electromagnetic screening to the building and equipment enclosures. Source Recommendation ITU-T K.78 was approved on 29 June 2009 by ITU-T Study Group 5 (2009-2012) under Recommendation ITU-T A.8 procedures. Keywords High altitude electromagnetic pulse (HEMP), immunity
5、, security, telecommunication equipment. ii Rec. ITU-T K.78 (06/2009) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sec
6、tor (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets ever
7、y four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview
8、, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is volunta
9、ry. However, the Recommendation may contain certain mandatory provisions (to ensure e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the n
10、egative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve th
11、e use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommenda
12、tion, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http
13、:/www.itu.int/ITU-T/ipr/. ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T K.78 (06/2009) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Terms d
14、efined in this Recommendation . 3 4 Abbreviations and acronyms 3 5 Equipment test requirements 4 5.1 Early time HEMP (E1) . 4 5.2 Intermediate time HEMP (E2) 4 5.3 Late time HEMP (E3) . 5 6 Test methods . 5 6.1 Radiated tests 5 6.2 Conducted tests . 5 7 Protection concepts for buildings and enclosur
15、es . 6 7.1 Protection concepts for buildings . 6 7.2 Protection concepts for shielded enclosures . 7 8 HEMP immunity tests and levels . 7 8.1 Immunity test 7 8.2 Performance criteria . 7 8.3 HEMP immunity requirements for equipment . 8 8.4 HEMP immunity tests levels 8 Annex A Guide for application o
16、f protection approach 12 A.1 Introduction 12 A.2 Protection approaches . 12 A.3 Protection concepts . 12 A.4 Topological considerations . 14 Appendix I Immunity level comparison between Recommendations ITU-T K.48/ITU-T K.20 and IEC 61000-6-6 17 Bibliography. 21 iv Rec. ITU-T K.78 (06/2009) Rec. ITU-
17、T K.78 (06/2009) 1 Recommendation ITU-T K.78 High altitude electromagnetic pulse immunity guide for telecommunication centres 1 Scope This Recommendation gives guidance on the protection of telecommunication centre equipment, such as switching, transmission, radio, and power, from damage and disrupt
18、ion due to a high altitude electromagnetic pulse (HEMP). The overall radiated and conducted immunity is a combination of the inherent equipment immunity, SPD surge mitigation and the electromagnetic screening of building and equipment enclosures. This Recommendation discusses immunity contribution o
19、f each item and defines an immunity test approach and testing levels. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were
20、valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendati
21、ons is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T K.11 Recommendation ITU-T K.11 (2009), Principles of protection against overvoltages and overcurrents. ITU-T K.20 Recommendation ITU-T
22、 K.20 (2008), Resistibility of telecommunication equipment installed in a telecommunications centre to overvoltages and overcurrents. ITU-T K.46 Recommendation ITU-T K.46 (2008), Protection of telecommunication lines using metallic symmetric conductors against lightning-induced surges. ITU-T K.47 Re
23、commendation ITU-T K.47 (2008), Protection of telecommunication lines using metallic conductors against direct lightning discharges. ITU-T K.48 Recommendation ITU-T K.48 (2006), EMC requirements for telecommunication equipment Product family Recommendation. IEC 61000-2-9 IEC 61000-2-9 (1996), Electr
24、omagnetic compatibility (EMC) Part 2-9: Environment Description of HEMP environment Radiated disturbance. IEC 61000-2-10 IEC 61000-2-10 (1998), Electromagnetic compatibility (EMC) Part 2-10: Environment Description of HEMP environment Conducted disturbance. IEC 61000-2-11 IEC 61000-2-11 (1999), Elec
25、tromagnetic compatibility (EMC) Part 2-11: Environment Classification of HEMP environments. IEC 61000-4-2 IEC 61000-4-2 (2008), Electromagnetic compatibility (EMC) Part 4-2: Testing and measurement techniques Electrostatic discharge immunity test. IEC 61000-4-4 IEC 61000-4-4 (2004), Electromagnetic
26、compatibility (EMC) Part 4-4: Testing and measurement techniques Electrical fast transient/burst immunity test. 2 Rec. ITU-T K.78 (06/2009) IEC 61000-4-5 IEC 61000-4-5 (2005), Electromagnetic compatibility (EMC) Part 4-5: Testing and measurement techniques Surge immunity test. IEC 61000-4-11 IEC 610
27、00-4-11 (2004), Electromagnetic compatibility (EMC) Part 4-11: Testing and measurement techniques Voltage dips, short interruptions and voltage variations immunity tests. IEC 61000-4-13 IEC 61000-4-13 (2002), Electromagnetic compatibility (EMC) Part 4-13: Testing and measurement techniques Harmonics
28、 and interharmonics including mains signalling at a.c. power port, low frequency immunity tests. IEC 61000-4-23 IEC 61000-4-23 (2000), Electromagnetic compatibility (EMC) Part 4-23: Testing and measurement techniques Test methods for protective devices for HEMP and other radiated disturbances. IEC 6
29、1000-4-25 IEC 61000-4-25 (2001), Electromagnetic compatibility (EMC) Part 4-25: Testing and measurement techniques HEMP immunity test methods for equipment and systems. IEC/TR 61000-4-32 IEC/TR 61000-4-32 (2002), Electromagnetic compatibility (EMC) Part 4-32: Testing and measurement techniques High-
30、altitude electromagnetic pulse (HEMP) simulator compendium. IEC 61000-5-3 IEC 61000-5-3 (1999), Electromagnetic compatibility (EMC) Part 5-3: Installation and mitigation guidelines HEMP protection concepts. IEC 61000-6-6 IEC 61000-6-6 (2003), Electromagnetic compatibility (EMC) Part 6-6: Generic sta
31、ndards HEMP immunity for indoor equipment. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 antenna port IEC 61000-6-6: A port that is connected to an antenna, either directly or by a cable. The antenna may be external or internal to the
32、 building. NOTE Antenna ports connected to antennas internal to the building are covered by signal ports. 3.1.2 cable port IEC 61000-6-6: A port at which a conductor or cable is connected to the apparatus IEC 61000-6-6. 3.1.3 electrical fast transient/burst (EFT/B) IEC 61000-4-4: The 5/50 ns pulse d
33、efined in IEC 61000-4-4. 3.1.4 enclosure port IEC 61000-6-6: A physical boundary of the apparatus which electromagnetic fields may radiate through or impinge upon. The equipment case is normally considered the enclosure port (see Figure 1). K.78(09)_F01Signal portFunctional earth porta.c. power port
34、d.c. power portEnclosure portsApparatusFigure 1 Example of ports 3.1.5 functional earth port IEC 61000-6-6: A cable port other than a signal, control or power port, intended for connection to earth for purposes other than safety (see Figure 1). Rec. ITU-T K.78 (06/2009) 3 3.1.6 high voltage (HV) tra
35、nsmission line IEC 61000-4-25: Power line with a nominal a.c system voltage equal to or greater than 100 kV. 3.1.7 immunity (to a disturbance) b-IEC 60050-161: The ability of a device, equipment or system to perform without degradation in the presence of an electromagnetic disturbance. 3.1.8 large H
36、EMP simulator IEC 61000-6-6 IEC 61000-4-25: Transient electromagnetic pulse test facility with a test volume sufficiently large to test objects with cubical dimensions equal to or greater than 1 m 1 m 1 m. 3.1.9 low voltage (LV) power circuit IEC 61000-6-6: Power circuit with a nominal a.c voltage e
37、qual to or less than 1. 3.1.10 medium voltage (MV) b-IEC 60050-601: Any set of voltage levels lying between low and high voltage. NOTE The boundaries between medium and high voltage levels overlap and depend on local circumstances and history or common usage. Nevertheless, the band 30 kV to 100 kV f
38、requently contains the accepted boundary. 3.1.11 power port IEC 61000-6-6: Point at which a conductor or cable carrying the electrical power needed for operation of the equipment is connected to the apparatus (see Figure 1). 3.1.12 signal port IEC 61000-6-6: A cable port at which there is a cable ca
39、rrying information for transferring data to or from the apparatus. Examples are input/output (I/O) data ports and telecom ports, etc., (see Figure 1). 3.1.13 small radiated test facility IEC 61000-6-6 IEC 61000-4-25: Laboratory transient electromagnetic pulse test facility such as a transverse elect
40、romagnetic (TEM) cell with a test volume sufficiently large to test objects with cubical dimensions of less than 1 m 1 m 1 m. 3.1.14 surge protection device (SPD) b-IEC 61643-21: A device to suppress line conducted overvoltages and currents, such as surge suppressors defined in b-IEC 61643-21. 3.2 T
41、erms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 HEMP immunity test: The HEMP immunity test is made up of four types of tests. The radiated test is defined in clause 5 of IEC 61000-4-25, and is used with a large HEMP simulator and a small radiated test facil
42、ity. The other three types are the conducted tests along the HEMP waveforms; early-, intermediate- and late-HEMP. These are also defined in clause 5 of IEC 61000-4-25. 3.2.2 minimum immunity requirement against HEMP: When the building concept level is 5 or 6, the equipment immunity level is at the m
43、inimum level. The levels are defined in clause 8 and Annex A, and a comparison of immunity levels is tabulated in Appendix I. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: E1 Early time high altitude electromagnetic pulse electric field E2 Intermedia
44、te time high altitude electromagnetic pulse electric field E3 Late time high altitude electromagnetic pulse electric field EFT/B Electrical Fast Transient/Burst EM Electromagnetic EMC Electromagnetic Compatibility 4 Rec. ITU-T K.78 (06/2009) EMI Electromagnetic Interference EMP Electromagnetic Pulse
45、 ESD Electrostatic Discharge EUT Equipment Under Test HEMP High altitude Electromagnetic Pulse HV High Voltage I/O Input/Outpout LV Low Voltage MV Medium Voltage PoE Point of Entry RF Radio Frequency SE Shielding Effectiveness TEM Transverse Electromagnetic 5 Equipment test requirements This clause
46、describes the three types of conducted HEMP test. 5.1 Early time HEMP (E1) The waveform rise time and time-to-half value are very short, and the peak value is very high. The EM field affects equipment not only through power and telecommunication lines, but also directly through the enclosure port. A
47、ccumulation through the length of the cable is not considerable, because the wavelength is in the range of tens of cm to about 100 m. This disturbance is similar to the electrical fast transient/burst (EFT/B) To protect telecommunication centres from this phenomenon, it is necessary to: subject all
48、enclosed equipment to a radiated immunity test, as specified in clause 8.4.1; subject all cable ports of all enclosed equipment to a conducted immunity test, as specified in clause 8.4.2. NOTE A result of the very short duration of the E1 pulse in the time domain is that the pulse contains component
49、s in the frequency domain that can efficiently couple to metallic cables with lengths in the 0.1-100 m range. This includes all metallic cables within the telecommunication centre and all externally attached metallic telecommunication and power cables. 5.2 Intermediate time HEMP (E2) The waveform rise time and time-to-half value, and the peak value are medium. The waveform of intermediate time HEMPs is similar to
