1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T K.78 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (06/2016) SERIES K: PROTECTION AGAINST INTERFERENCE High altitude electromagnetic pulse immunity guide for telecommunication centres Recommendation ITU-T K.78 Rec. ITU-T
2、K.78 (06/2016) i Recommendation ITU-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 tel
3、ecommunication centres for functions 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 conc
4、ept of surge protective devices (SPDs) for surge mitigation and electromagnetic screening to the building and equipment enclosures. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T K.78 2009-06-29 5 11.1002/1000/9667 2.0 ITU-T K.78 2016-06-29 5 11.1002/1000/12876 Keywords Ele
5、ctromagnetic security, high altitude electromagnetic pulse, HEMP, intentional electromagnetic interference, IEMI, immunity. * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handl
6、e.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T K.78 (06/2016) 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 Sector (ITU
7、-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 every four y
8、ears, 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, the ne
9、cessary 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 voluntary. Howe
10、ver, 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 negative
11、 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 RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of
12、 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 Recommendation, IT
13、U 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:/www.it
14、u.int/ITU-T/ipr/. ITU 2016 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 (06/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 2 3.1 Terms defined elsewhere 2 3.2 Ter
15、ms defined in this Recommendation . 3 4 Abbreviations and acronyms 3 5 Conventions 4 6 Equipment test requirements 4 6.1 Early time HEMP (E1) . 4 6.2 Intermediate time HEMP (E2) 4 6.3 Late time HEMP (E3) . 5 7 Test methods . 5 7.1 Radiated tests 5 7.2 Conducted tests . 5 8 Protection concepts for bu
16、ildings and enclosures . 6 8.1 Protection concepts for buildings . 6 8.2 Protection concepts for shielded enclosures . 7 9 HEMP immunity tests and levels . 7 9.1 Immunity test 7 9.2 Performance criteria . 8 9.3 HEMP immunity requirements for equipment . 8 9.4 HEMP immunity tests levels 8 Appendix I
17、Immunity level comparison between Recommendations ITU-T K.48/ITU-T K.20 and IEC 61000-6-6 12 Bibliography. 16 Rec. ITU-T K.78 (06/2016) 1 Recommendation ITU-T K.78 High altitude electromagnetic pulse immunity guide for telecommunication centres 1 Scope This Recommendation gives guidance on the prote
18、ction of telecommunication centre equipment, such as switching, transmission, radio, and power, from damage and disruption 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 th
19、e electromagnetic screening of building and equipment enclosures. This Recommendation discusses immunity contribution of 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 referen
20、ce in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were 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 re
21、cent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations 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 Recommenda
22、tion ITU-T K.11 (2009), Principles of protection against overvoltages and overcurrents. ITU-T K.20 Recommendation ITU-T K.20 (2015), Resistibility of telecommunication equipment installed in a telecommunications centre to overvoltages and overcurrents. ITU-T K.46 Recommendation ITU-T K.46 (2012), Pr
23、otection of telecommunication lines using metallic symmetric conductors against lightning-induced surges. ITU-T K.47 Recommendation ITU-T K.47 (2012), Protection of telecommunication lines against direct lightning flashes. ITU-T K.48 Recommendation ITU-T K.48 (2006), EMC requirements for telecommuni
24、cation equipment Product family Recommendation. ITU-T K.115 Recommendation ITU-T K.115 (2015), Mitigation methods against electromagnetic security threats. IEC 61000-2-9 IEC 61000-2-9 (1996), Electromagnetic compatibility (EMC) Part 2 Environment Section 9: Description of HEMP environment Radiated d
25、isturbance. Basic EMC publication. 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), Electromagnetic compatibility (EMC) Part 2-11: Environment Classification o
26、f 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. 2 Rec. ITU-T K.78 (06/2016) IEC 61000-4-4 IEC 61000-4-4 (2012), Electromagnetic compatibility (EMC) Part 4-4: Testing and m
27、easurement techniques Electrical fast transient/burst immunity test. IEC 61000-4-5 IEC 61000-4-5 (2014), Electromagnetic compatibility (EMC) Part 4-5: Testing and measurement techniques Surge immunity test. IEC 61000-4-11 IEC 61000-4-11 (2004), Electromagnetic compatibility (EMC) Part 4-11: Testing
28、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 and interharmonics including mains signalling at a.c. power port, low
29、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 61000-4-25 IEC 61000-4-25 (2001), Electromagnetic compatibility (EMC) Pa
30、rt 4-25: Testing and measurement techniques HEMP immunity test methods for equipment and systems. IECTR 61000-4-32 IECTR 61000-4-32 (2002), Electromagnetic compatibility (EMC) Part 4-32: Testing and measurement techniques High-altitude electromagnetic pulse (HEMP) simulator compendium. IEC 61000-6-6
31、 IEC 61000-6-6 (2003), Electromagnetic compatibility (EMC) Part 6-6: Generic standards 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 antenn
32、a, either directly or by a cable. The antenna may be external or internal to the 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.
33、3.1.3 electrical fast transient/burst (EFT/B) IEC 61000-4-4: The 5/50 ns pulse defined 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
34、port (see Figure 1). K . 78 ( 09 ) _F 01S i g n a l p o r tF u n c t i o n a l e a r t h p o r ta . c . p o we r p o r td . c . p o we r p o r tEn c l o s u r e p o r t sAp p a r a t u sFigure 1 Example of ports Rec. ITU-T K.78 (06/2016) 3 3.1.5 functional earth port IEC 61000-6-6: A cable port othe
35、r than a signal, control or power port, intended for connection to earth for purposes other than safety (see Figure 1). 3.1.6 high voltage (HV) transmission 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 600
36、50-161: The ability of a device, equipment or system to perform without degradation in the presence of an electromagnetic disturbance. 3.1.8 large HEMP simulator IEC 61000-6-6 IEC 61000-4-25: Transient electromagnetic pulse test facility with a test volume sufficiently large to test objects with cub
37、ical 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 equal 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 b
38、etween medium and high voltage levels overlap and depend on local circumstances and history or common usage. Nevertheless, the band 30 kV to 100 kV frequently 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
39、 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 carrying 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
40、.1.13 small radiated test facility IEC 61000-6-6 IEC 61000-4-25: Laboratory transient electromagnetic pulse test facility such as a transverse electromagnetic (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 protective de
41、vice (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 Terms 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
42、 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 facility. 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
43、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 minimum level. The levels are defined in clause 9 and clause 6.1 of ITU-T K.115, and a comparison of immunity levels is tabulated in Appendix I. 4 Abbrev
44、iations and acronyms This Recommendation uses the following abbreviations and acronyms: EFT/B Electrical Fast Transient/Burst EM Electromagnetic EMC Electromagnetic Compatibility EMI Electromagnetic Interference 4 Rec. ITU-T K.78 (06/2016) EMP Electromagnetic Pulse ESD Electrostatic Discharge EUT Eq
45、uipment Under Test HEMP High altitude Electromagnetic Pulse HV High Voltage I/O Input/Output LV Low Voltage MV Medium Voltage RF Radio Frequency SE Shielding Effectiveness SPD Surge Protective Device TEM Transverse Electromagnetic 5 Conventions This Recommendation uses the following conventions: E1
46、Early time high altitude electromagnetic pulse electric field E2 Intermediate time high altitude electromagnetic pulse electric field E3 Late time high altitude electromagnetic pulse electric field 6 Equipment test requirements This clause describes the three types of conducted HEMP test. 6.1 Early
47、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. Accumulation through the length of the cable is not considera
48、ble, 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 enclosed equipment to a radiated immunity test, as specified
49、 in clause 9.4.1; subject all cable ports of all enclosed equipment to a conducted immunity test, as specified in clause 9.4.2. NOTE A result of the very short duration of the E1 pulse in the time domain is that the pulse contains components 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 cent
