GB/Z 18039.1-2000 Electromagnetic compatibility environment Classification of electromagnetic environment
Some standard content:
GB/Z18039.1—2000
This guidance technical document is equivalent to the IEC technical report IEC61000-2-5:1996 "Electromagnetic compatibility Part 2: Environment Part
: Classification of electromagnetic environment". This guidance technical document classifies the electromagnetic environment in which electrical and electronic equipment are located, thereby providing technical specifications for obtaining electromagnetic compatibility. This guidance technical document is one of the "Electromagnetic Compatibility Environment" series of national standardization guidance technical documents, which currently include the following: GB/Z18039.1-2000 Electromagnetic compatibility environment Classification of electromagnetic environment GB/218039.2--2000 Electromagnetic compatibility environment Evaluation of low-frequency conducted disturbance emission level of industrial equipment power supply This guidance technical document is for reference only. Suggestions and opinions on this guidance technical document should be reported to the standardization administrative department of the State Council.
Appendix A, Appendix B and Appendix C of this guidance technical document are prompt appendices. This guidance technical document was proposed by the State Power Corporation. This guidance technical document is under the jurisdiction of the National Electromagnetic Compatibility Standardization Joint Working Group. The responsible drafting unit of this guidance technical document is Wuhan High Voltage Research Institute of State Power Corporation. The main drafters of this guidance technical document are: Nie Dingzhen, Wu Xiong, Wan Baoquan, Lang Weichuan, Jiang Hong, Chen Xiaokang. 618
GB/Z18039.1-2000
IEC Foreword
1) The International Electrotechnical Commission (IEC) is a worldwide standardization organization composed of the National Electrotechnical Commissions (IEC National Committees) of all participating countries. Its purpose is to promote international consensus on all issues related to standardization in the field of electrical and electronic technology. To this end, in addition to carrying out other activities, it also publishes international standards, which are formulated by technical committees. Any IEC National Committee interested in the formulation of the project may participate. International organizations, governmental and non-governmental organizations that have liaison with IEC may also participate in this work. IEC and the International Organization for Standardization (ISO) work closely together under the conditions determined by negotiation between the two organizations. 2) Since each technical committee has representatives from all countries interested in the relevant development project, the formal decisions or agreements made by the IEC on the relevant technical content express international consensus as much as possible. 3) The resulting documents can be published in the form of standards, technical reports or guidelines, and are recommended for international use and accepted by the National Committees in this sense.
4) In order to promote international consensus, the IEC National Committees should convert IEC International Standards into their national and regional standards as much as possible. Any differences between the corresponding national or regional standards and IEC International Standards should be clearly stated in the standards. The main task of the IEC Technical Committee is to formulate international standards. In special cases, the Technical Committee may publish one of the following types of technical reports.
· Type 1, when it cannot be published as an international standard despite repeated efforts; · Type 2. When the subject is still in the technical development stage, or for any other reason it cannot be agreed to be an international standard in the future;
· Type 3, when the Technical Committee collects various materials, such as "scientific development trends" in the routine process of publishing international standards. Category 1 and 2 technical reports are reviewed within three years of publication to determine whether they can become an international standard. Category 3 technical reports do not need to be reviewed until the information they provide is considered no longer valid or useful. IFC61000-2-5 is a Category 2 technical report, which was prepared by the following committee: IEC Technical Committee 77 (Electromagnetic Compatibility) Subcommittee 77B (High Frequency Phenomena). This technical report is Part 2, Subpart 5 of IEC 61000 and has the status of a basic EMC publication in accordance with IEC Guide 107.
The text of this report is based on the documents in the table below: Committee Draft
77B(SEC)122
Full information on the vote to approve this report can be found in the voting report in the table above. Annexes A, B and C are for reference only. Voting Report
77B/142/RVC
GB/Z18039.1--2000
IEC Introduction
This standard is part of the IEC61000 series of standards, which consists of the following: Part 1: General
General considerations (overview, basic principles)
Definitions, terms
Part 2: Environment
Description of environment
Classification of environment
Compatibility level
Part 3: Limits
Emission limits
Immunity limits (as they are not within the responsibility of the product committee) Part 4: Test and measurement techniques
Measurement techniques
Test techniques
Part 5: Installation and mitigation guidelines
Installation guidelines
Mitigation methods and devices
Part 6: Generic standards
Part 9: Others
Each part is divided into several sub-parts, which are published as International Standards or Technical Reports. 1 Overview
National Standardization Guiding Technical Document of the People's Republic of China Electromagnetic compatibility environment
Classification of electromagnetic environments
Electromagnetic compatibility Environment.-Classification of electromagnetic environments1.1 Scope
GB/7.18039.1-2000
idt IFC:61000-2-5:1996
This guiding technical document will provide guidance to those responsible for establishing immunity standards for equipment or systems. It is not a technical specification. Its purpose is to classify electromagnetic environments so that the technical specifications for immunity requirements of equipment equipped with electrical or electronic components can be better used to achieve electromagnetic compatibility. This guiding technical document also gives basic guidance on the selection of immunity levels. These data apply to equipment, subsystems or systems that use electromagnetic energy in specific locations specified in this guidance technical document. This guidance technical document does not involve the environment inside transportation equipment (vehicles, traction vehicles, ships, aircraft), but considers their impact on the surrounding environment. It should be noted that the immunity requirements for the selected equipment will not only be limited by the environment, but also by the requirements of use (such as reliability or safety), which makes it more stringent than the general requirements. For more general purposes (such as general standards and product standards), when determining the immunity level, statistical, economic aspects and common experience in certain applications may also be considered. 1.2 Reference standards
The provisions contained in the following standards constitute the provisions of this guidance technical document by reference in this guidance technical document. When this guidance technical document is published, the versions shown are valid. All standards will be revised, and all parties using this guidance technical document should explore the possibility of using the latest version of the following standards. GB/T4365--1995 Electromagnetic compatibility terminology (idtIEC60050 (61): 1990) 1.3 Method
The classification of the electromagnetic environment is based on the classification or description of the electromagnetic phenomena that are the main components of the typical position, and it is not based on the existing test procedures. However, when choosing between phenomena with the same probability, using existing test procedures (if appropriate) for adjustment will simplify the situation and make the recommended values more acceptable. The definition of electromagnetic environment in GB/T4365 mentions *electromagnetic phenomena. The term "disturbance" (disturbancdegrce) is used in this technical document to quantify the phenomena that constitute the electromagnetic environment.mi is irrelevant to considerations of test grade. This guidance document does not use the term "severity level" to describe the environment, because in other standards, it is used as a prescribed immunity test level. Therefore, in the classification method, the concept and terminology of electromagnetic phenomena are the starting point for defining the electromagnetic environment and selecting the disturbance level. Chapters 4, 5 and 6 of this guidance document are the first step of this process. A basic class of electromagnetic phenomena has been classified: low-frequency phenomena, high-frequency phenomena and electrostatic discharge. In the first step, the properties of the phenomenon (amplitude, waveform, source impedance, frequency of occurrence, etc.) are defined to determine the expected range of disturbance levels. In the second step, for the specified location category, a single value is found from this range as the most representative value of a certain phenomenon, thereby specifying the compatibility level for that type of location. This process is illustrated in Figure 1, which points out how to use two sets of tables: one is a phenomenon-related input table that determines the range of disturbance levels for a given phenomenon; the other is a location-related output table, that is, for each phenomenon determined in the input table, a table recommending a penetration level value in each type of location.
Approved by the State Administration of Quality and Technical Supervision on April 3, 2000, and implemented on December 1, 2000
GH/Z 18039. 12000
The environment is ultimately classified into location categories and corresponds to compatibility levels, which are discussed in Chapter 7, and specific examples of location categories are given in Appendix A. The attributes of these location categories are based on the main electromagnetic characteristics of the location. The location of an environment is not based on its geographical or structural characteristics. For example, it is not enough to classify the location with the term "wide". In a factory, there will be different location situations, such as computer rooms, general offices, and specialized production workshops. The final classified location mark means a clear definition of the main electromagnetic properties. Locations different from those listed in Appendix A can also be classified, and tables can be added as needed. It should be noted that this classification is based on environmental data with acceptable probability factors collected around 1990. The disturbance levels given in Appendix A are provided as examples of compatibility levels to provide guidance to other standard committees, but not as standard permissible levels or immunity requirements. These values are subject to uncertainty and cannot describe extreme environments. Input table related to the phenomenon According to the classification of the disturbance degree, a table is used for each phenomenon: A = controlled environment Natural environment X - controlled environment Phenomenon abc Output table related to the location Single-valued parameter for each phenomenon and port, one table is used for each location category Location category xyz Figure 1 Schematic diagram of the "two-step method" for classification using an input table related to the phenomenon and an output table related to the location 2 Definitions For definitions of general topics on electromagnetic compatibility, refer to GB/T 4365. This guidance technical document uses the following definitions. 2.1 Definitions of electromagnetic compatibility with annotations 2.1.1 (Electromagnetic) compatibility level The maximum electromagnetic disturbance level expected to be applied to a device, equipment or system operating under specified conditions. Note: In practice, the electromagnetic disturbance level is not the absolute maximum level, but it may be exceeded with a small probability. 2.1.2 Disturbance degree The quantitative intensity specified within the range of disturbance levels corresponding to a specific electromagnetic phenomenon in the environment of concern: 2.1.3 Disturbance level levelGB/Z18039.1--2000
The given electromagnetic disturbance level is measured by the prescribed method. 2.1.4 Electromagnetic compatibility (EMC) The ability of a device, equipment or system to operate normally in its electromagnetic environment and not cause unacceptable electromagnetic disturbance to anything in the environment
Note: For simplicity, this guidance technical document uses the term "equipment (item)" instead of the repeated "device, equipment or system (tevict.etuipmtnsyhien\
2.1.5 (Electromagnetic) environment (elecrromagnetic) environment The environment of all things in a given place The sum of electromagnetic phenomena. For example, this sum is time-dependent and their description may require statistical methods. 2 It is very important not to confuse the electromagnetic environment with the location itself. 2.1.6 (Electromagnetic) disturbance Any electromagnetic phenomenon that may cause a degradation of the performance of a device, equipment or system or cause damage to living or non-living matter! Note: Electromagnetic disturbance may be electromagnetic noise, unwanted signals or changes in the propagation medium itself. 2.1.7 (Electromagnetic) susceptibility The ability of a device, equipment or system to avoid degradation in performance in the presence of electromagnetic disturbance. Note: The higher the susceptibility, the lower the immunity.
2.1.8 (to disturbance) immunity The ability of a device, equipment or system to face electromagnetic disturbance without degradation of operating performance. 2.1.9 Immunity level The minimum level of disturbance that can be applied to a device, equipment or system and still operate normally and maintain the required performance level.
2. 1. 10 Location (EMC) location (EMC) is a location or place classified according to electromagnetic characteristics. 2.1.11 Location Class Location Class A collection of locations with common characteristics related to the type and density of electrical and electronic equipment used (including installation conditions and external influences) (see Appendix A): 2.2 Abbreviations AST) Variable speed transmission (also called variable speed transmission) CW Continuous wave Electrostatic discharge Test equipment Industrial, scientific and medical equipment Information technology equipment Magnetic resonance imaging (also called nuclear magnetic resonance) International Telecommunication Union International Radiation Protection Commission Civil radio frequency bands 3 User Guide 3.1 Basic theory of the classification system The purpose of the classification system is to determine a finite set of parameters and related values. When determining performance requirements, this GB/Z can be selected. 18039.12000
values. The significance of this system is mainly in terms of economic power, that is, reducing the disturbance level category of the equipment produced by the manufacturer. The system also determines the requirements for appropriate connections (if any). The recommended classification system is quite comprehensive and covers most electromagnetic phenomena. This does not mean that the immunity of a given device should be tested against all these phenomena, but it is sufficient to select a limited number of phenomena based on the environment of concern and the inherent characteristics of the equipment. 3.2 Environmental phenomena
Expecting electronic systems to work without interference in the electromagnetic environment is very complex. For this classification, a wide range of environmental phenomena has been defined to describe all disturbances:
Low-frequency phenomena (conducted and radiated, except ESI)); high-frequency phenomena (conducted and radiated, except ESD); electrostatic discharge (ESID) phenomena (conducted and radiated). This division is necessary to identify electromagnetic disturbances that occur in special media. When studying the electromagnetic environment, the wavelength of the disturbance considered is formally measured by "long and small" or "large and small". If the wavelength is much larger than the size of the system (or line), then the system is small or the line is a short line. Therefore, in this case, the frequency is low, because the frequency is inversely proportional to the wavelength. When the ratio of its size to the wavelength is greater than 1, large, long and high are used to describe the system. However, the low frequency mentioned in this guidance technical document refers to the main component in the disturbance spectrum, which is lower than 9kHz; and the high frequency refers to its frequency (much) higher than 9kHz. Radiated disturbances appear in the medium around the equipment, while conducted disturbances appear in various metallic media. The concept of port (disturbance affects the equipment through the port) allows the following media to be distinguished: 1) Shell: 2) AC power supply; 3) DC power supply; 4) Control/signal line; 5) Connection between the system and the ground or reference ground. The source, coupling and propagation characteristics are related to the type of medium. The final table in Appendix A gives the compatibility level of various location categories in the factory, which is made according to the concept of the corresponding port. 3.3 Simplification of basic environmental data
It is neither possible nor necessary to fully describe the electromagnetic environment. Therefore, any description is limited to describing certain characteristics of the environment. The first step of the description should be to select electromagnetic characteristics corresponding to various phenomena that can produce electromagnetic disturbances. Table 1 lists the types of phenomena. In this guidance technical document, the dividing line between low frequency and high frequency is generally considered to be 9 kHz; however, when a disturbance has a small overshoot and enters another frequency range, when determining its disturbance type, the dividing line of the frequency range that accounts for the main component may need to be slightly moved to keep the phenomenon within the description range. If the selected date is also specified, then this appropriate choice is the only valid one. Considering that there can be many coupling mechanisms between the equipment and the electromagnetic environment, it is obvious that more information about the environment will be needed in order to accurately assess the required immunity level of the equipment: the accuracy of the description of the magnetic environment will inevitably be limited by the following: some aspects of the environment will be ignored due to lack of information; some aspects of the environment will be ignored due to the complexity of the classification system considered; ... In order to consider only those events that are likely to occur, statistical methods may be necessary. The selection of the type of disturbance will be subject to the first two limitations. Statistical methods are used to determine the category of the environment and to select a single value of the compatibility level, rather than a range of values.
When formulating this guidance document, the basic data available show that the conducted and radiated disturbances that are expected to occur in the various environments encountered when the equipment is used vary greatly. Using the combination of basic data, it is convenient to evaluate the ability of the equipment to withstand these environments or the effectiveness of the measures to mitigate the disturbances through laboratory tests. This combination makes it possible to select a few representative disturbance phenomena, so that the tests are meaningful and repeatable.
To help designers and users of equipment make appropriate choices when determining immunity test levels, the classification method indicates that for each type of location there is only one compatibility level for the phenomenon. The characteristics of each phenomenon are provided in a table form, and the selection can be made based on the table. This method provides a common benchmark for specifying the performance requirements of equipment expected to be installed in various locations, and also provides an appropriate compromise between conservative design and intentional reduction of cost margins. The technical specifications of these requirements for specific equipment belong to the scope of product standards and are therefore not discussed in this guidance technical document. For a given device, the operating environment is formed by the presence and characteristics of the disturbance source and the installation conditions adopted. Typical GB/Z18039.12000
installation practices take into account measures to mitigate disturbances, which can be achieved through isolation, shielding and suppression. Therefore, when the station recommends its disturbance levels for specific locations with various installation practices, it is important to consider the impact of these installation practices. This guidance technical document gives representative disturbance levels for various installation conditions that may be encountered in these locations. Table 1 Basic phenomena of electromagnetic disturbance
Low-frequency conduction phenomenon:
Harmonics, interharmonics
·Signal voltage
Voltage fluctuation
Voltage sags and short interruptions
·Voltage unbalance
Power supply frequency variation
Low-frequency induced voltage
DC in AC network
Low-frequency radiation phenomenon:
|High-frequency conduction phenomenon:
\Induced continuous (CW) wave voltage and current single transient
·Oscillatory transient
High-frequency radiation phenomenon:
: Electric field
Electromagnetic field
·Continuous wave
·Transient
Electrostatic discharge (ESID)) phenomenon
Nuclear electromagnetic pulse (NEMP)\
*Not considered in this guiding technical document.
The list of disturbance levels contains Class "A" (for which certain mitigation and control measures may be required to meet the specified requirements) and Class X\ (that is, taking into account that in some cases, exceptional conditions may prevail and require special attention). Class A\ corresponds to situations where these environments are more or less controlled by the type of building or by the installation practices inherent in the particular location. Class X\ corresponds to situations where the disturbance levels are higher than those generally encountered.
For any classification, the classification depends on the majority of them. This classification recognizes that there may be exceptional requirements for any specified location. The result of this situation is that the design must take into account the operation of equipment under special conditions. For example, a special type of operating transient that does not occur frequently in a certain type of location. For this special disturbance, whether the equipment should be designed to be "immune\" will depend on whether the effects they are subjected to are temporary (for example, attenuated reception, although this amount is undesirable, but it is acceptable) or permanent and unacceptable (equipment damage or malfunction causing unacceptable consequences). If no particular performance requirements are expected at a given location (which is the general case), then the procedure is simplified to: a) select the appropriate location based on the location categories specified in Chapter 7 and Appendix A; b) select the required immunity according to the principles described in Chapter 8. GB/718039.1.2000
This guidance document is not intended to specify immunity, but allows other relevant professional standardization technical committees to make choices on a reasonable and well-founded basis in the absence of equipment interference. The data listed in the following tables refer to well-known environmental conditions, such as low-frequency phenomena. In other cases, only representative values for classification are recommended. 4 Low-frequency electromagnetic phenomena
4.1 Low-frequency conduction phenomena
4.1.1 Harmonics (≤3kHz)
Harmonic voltages are caused by harmonic currents of non-linear loads flowing through network impedances (frequency is the harmonic frequency) and causing corresponding voltage drops. The currents and voltages applied by various sources (such as phase-controlled rectifiers) are added vectorially so that the composite voltage is less than or equal to the algebraic sum of all applied voltages. Two categories of sources can be distinguished: · In low voltage networks, a large number of small sources from various electronic loads with rectifier input (household appliances, televisions, personal computers, etc.);
In low, medium or high voltage networks, a large number of small sources from industrial loads (such as variable speed drives), traction rectifiers and other independent sources are the main cause of harmonics in public distribution networks. In industrial areas, large sources are dominant, and there are also harmonics from residential areas. Table 2 shows the expected disturbance level range, individual harmonics and total harmonic distortion. Attention should be paid to the fact that not all harmonics will reach the corresponding value at the same time. Data on interharmonics are under consideration. 4.1.2 Signal voltage in power system
Power grids are designed for transmitting electric energy, but they can also be used to transmit information through "grid signal systems". The relevant standardization documents consider the following types of systems:
Ripple control systems used by power departments in public distribution networks, ranging from 100HIz to 3k1z, generally below 500Hz. The signal can reach up to 9% of the nominal voltage. Such systems are used in some European countries and some other regions; Table 2 Range of harmonic disturbance degree in low-voltage power system (unit: percentage of fundamental voltage) Disturbance degree
A (controlled)
X (harsh)
Distortion rate
Odd (not a multiple of 3)
1113.17,1923～25
Multiples of 3
≥2531911 521212
Consider item by item according to equipment requirements
*--0.2+12.5/n (n is the harmonic number)＊=3.3～1.0 (decreases with increasing frequency)Note
1.50.30.20.2
Consider item by item according to the situation
Class 1A is suitable for protected power supplies for equipment that is sensitive to harmonics (may be computers, measuring instruments, medical equipment, etc.). Even
Class 21 corresponds to the compatibility level specified for low-voltage public distribution networks (see IEC61000-2-2), and it is also suitable for industrial networks with mild interference (medium and small factories, commercial buildings).
Class 32 is suitable for industrial networks and large commercial buildings. Class 1X is suitable for industrial networks with strong interference (steel plants, etc.). The above values represent the level that does not exceed 95% of the time at the most burst point in the network according to the statistical distribution of time. They correspond to the compatibility levels given in IEC610002-2 and IEC61000-2-4. The power line carrier system used by the power department in the public distribution network ranges from 3kHz to 95kHz, and the signal level is allowed to reach 2.5% of the nominal voltage. However, these signals are strongly attenuated in the network (>40dB). This type of system is mainly used in the United States and is under development in other regions:
GB/718039.1--2000
For signal systems based on end users (residential or industrial), the frequency range in Europe is 95kHz118.5kHz (ITUI category area); in the United States and Japan it is 500kHz, and the signal level is allowed to reach 0.6% or 5% of the nominal voltage. Table 3 Range of signal voltage disturbance degree in power system (unit: percentage of nominal voltage) Frequency range, kHz
Disturbance degree
A-No signal network
1-Transmitting water near the transmitter
X-Under special conditions (resonance)
*Under test.
0.1kHz～0.5kHz:5%
55-- 148. 5
Consider each item according to the equipment requirements
3 kHz---9 kHz:
619 kHz~95 kHz:5%
0. 5 kHz~- 3 kHz :5% ~- 1. 3%Consider each item according to the situation
General: 6 yuan
Upper business area: 5 channels
118. 3 ~-506
2 -. 0. f(nV)
1A level: There may be residual signals, which are coupled by nearby systems with special borrowing numbers. This level is different from the other levels in the table. Level 8 is not a controlled environment. Moreover, some types of installations may provide some degree of protection against this disturbance phenomenon. When the disturbance comes from a neighboring network, it may be necessary to install a blocking circuit or an absorption circuit.
21 level: For the frequency range of 0.1kHz~3kHz, its value corresponds to the normal injection level in the actual equipment; for other frequency ranges, its value is the maximum allowable injection level measured on the reference impedance. These values are only used in the ITU Class [ area, and other values can be used in the IIU Class ! or Class ! areas.
3X level: Under normal circumstances, the signal will be attenuated in the network to some extent. However, under certain resonant conditions, the signal may be attenuated. In the range of ! ! kHz to 3kHz, the maximum signal allowed is 9% of the nominal voltage. 4.1.3 Power system voltage and frequency variations
4.1.3.1 Amplitude
50/60Hz power supply voltage amplitude is subject to various disturbances a) Continuous or randomly repeated rapid fluctuations (occurrence frequency range is 25 times/s to 1 time/min) within the normal operating range: the main disturbance effect of voltage fluctuations is to make lights flicker (mainly low-power incandescent lamps), causing physical discomfort. Generally speaking, fluctuations come from industrial loads, such as arc furnaces (high-voltage network), electric welding machines (low-voltage network), switching of large loads and capacitor banks. These rapid fluctuations should be separated from slow changes under normal conditions, and the latter cannot be considered as EMC problems. b) Voltage sags (U range is 10%-99% of the nominal voltage) and short interruptions (△=100% of the nominal voltage) can last from one cycle to several seconds. When the interruption lasts for more than 1 minute, it is no longer considered as a low-frequency EMC problem, but is considered as a power interruption. Voltage sags and short interruptions have various causes: - fuse action (a few milliseconds) to eliminate short circuits in low-voltage networks; faults in medium-voltage and high-voltage lines or other equipment, with or without automatic reclosing (100ms to 600)nis); - switching on and off of large loads, especially motors and capacitor banks. c) Voltage unbalance is a condition in a three-phase system in which the phases have different amplitudes or deviate from the normal phase relationship (3×120°). The degree of unbalance is usually defined according to the symmetrical component method, as the ratio of the negative sequence component (or zero sequence component) to the positive sequence component. Voltage unbalance is caused by unsymmetrical loads or large single-phase loads (such as traction systems or single-phase arc furnaces): 4.1.3.2 Frequency
The frequency of the power system is generally very stable and its variation is less than 0.1H2. However, when the network is disturbed, it will vary within a wide range, up to 3%. Large frequency drops are the result of large disturbances to the system. Disturbance degree
Phenomenon (source)
A (controlled)
x (momentary)
GB/Z 18039. 1 -2000
Table A Disturbance source (phenomenon) and disturbance degree range of voltage amplitude and frequency of power system Normal operation range
Voltage fluctuation
Low frequency induced voltage
Voltage temporary
((10%~99%0n）
(duration)
Short interruption
C99%00)
(duration)
Consider each item according to equipment requirements
600 ms
Consider each case
Voltage imbalance
Power supply frequency
Low-frequency currents flowing in adjacent cables (depending on the actual current, physical size, cable type, and other parameters) may induce low-frequency common-mode voltages in signal and control cables: the coupling impedance varies with the distance and effective parallel length of the adjacent cables. Table 5 describes the common-mode induced voltages. Differential mode voltages will also appear, and are related to the type of cable and terminal. Sources and levels of disturbance of low-frequency common-mode induced voltage in signal and control cables (unit: V) Table 5
Phenomenon (source)
Disturbance level
A (controlled)
X (harsh)
Frequency and harmonics of power cable carrier network under normal operating conditions 50 Hz～1 kHz2*
0. 15～~3
1 ~~20
1) Its value may be limited by ITU-T or other specified mitigation methods. 2) Within the range shown, the disturbance level decreases with increasing frequency 1 kHz-20 kHz
Consider item by item according to equipment requirements
Consider item by item according to the situation
3) It may be limited by gap insulation breakdown. Higher voltages may appear in ungrounded loops. 4.1.5 DC voltage in AC network
Under consideration.
4.2 Low-frequency radiated phenomena
4.2.1 Magnetic fields
Under power system fault conditions
50 Hz1 kHz
Power frequency magnetic fields of 50/60 Hz are generated by several sources: close to power lines, especially overhead lines; transformers or other power system equipment, and stray fields from industrial, office and household appliances. In areas with electric traction equipment, magnetic fields at electric railway frequencies will also be encountered. Harmonic frequency magnetic fields that can be effective only appear in special environments (converter stations and similar situations), and their impact on signal and control lines is more significant than on power supplies. Table 6 does not take into account transient fault conditions that occur in the power system. Table 6 Disturbance sources and disturbance levels of low-frequency magnetic fields (unit: A/m, DC or RMS value) Phenomenon (source)
Disturbance level
A (controlled)
Electric railway
Frequency 16%3
Power system frequency
50/60Hz3
Power system harmonics
0. 1 kHz～3 kH2
Consider each item according to the equipment requirements
Male power system is irrelevant
Disturbance degree
Phenomenon (source)
x (harsh)
GB/Z18039.1—2000
Table 6 (end)
Electric railway
Frequency 163g2)
Power system frequency
50/60H233
Consider each item according to the situation
1) At 1m above the ground, the geomagnetic field of about 20A/m~60A/m should be added, which is related to the position. The power system harmonics
0. 1 kHz~3 kHz
And the power system shop
2) At 20m away from the locomotive, the closer to the locomotive, the more significant the increase in the magnetic field. At 1m above the ground, the magnetic field at 23ri1 from a 3000kW locomotive is 1A/m. The signal system of some railway locomotives may also have a higher magnetic field strength than level 1. 3) For overhead lines, measure 1m above the ground. Below the center of the line, the amplitude of the magnetic field has a range. For home and commercial environments, the magnetic field amplitude ranges from 1A/m to 10A/m when measured at 0.3m from the source4) In the formula! is the order of the harmonic.
5) Where there is an audio induction coil, the long-term average magnetic field in the frequency range of 100Hz~5kHz may be 0.1A/m (level 3), see IEC 60118-4.
There are strong electric fields under high-voltage overhead power lines and in substations. The attenuation factor of the electric field for buildings under the lines is 10 to 20. The electric fields generated by household appliances are generally small. Table 7 Range of low-frequency electric fields and their disturbance levels (1m above the ground) Phenomenon (source)
Disturbance level www.bzxz.net
A (controlled)
x (harsh)
1) Residential environment, away from overhead lines.
DC lines
16Hz lines
Consider each item according to equipment requirements
Consider each item according to the situation
2) Outdoors, under overhead lines up to 30kV; indoors, under overhead lines up to 765kV. 3) Outdoors, under overhead lines up to 400kV. 4) In high-voltage power stations up to 400kV and under overhead lines up to 765kV. 5 High-frequency electromagnetic phenomena
High-frequency conduction phenomena
(unit km)
50/60Hz lines
It is generally believed that this interference occurs in a group of conductors in the system, which can be in the power supply network (AC or DC) or in various signal/control lines used in modern equipment. It is common that these systems are independent devices, and the voltage difference between conductors of different systems close to each other is not considered. Therefore, the ground coupling path (or reference ground) is considered to be one of the media for the occurrence of interference. These disturbances can be mainly divided into two types, each of which is characterized by the following set of attributes Continuous phenomena (induced CW voltage and current) Attributes: Amplitude
Source impedance
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