Iec 61000 2 2 2002

NORME INTERNATIONALE CEI IEC INTERNATIONAL STANDARD 61000 2 2 Deuxième édition Second edition 2002 03 Compatibilité électromagnétique (CEM) � Partie 2 2 Environnement � Niveaux de compatibilité pour l[.]

Définitions générales

3.1.1 perturbation (électromagnétique) tout phénomène électromagnétique qui, de par sa présence dans l’environnement électromagnétique, peut faire dévier un équipement électrique de sa performance attendue

3.1.2 niveau de perturbation amplitude d’une perturbation électromagnétique, mesurée et évaluée au moyen d’une méthode spécifiée

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The referenced documents are essential for the application of this document For dated references, only the specified edition is applicable, while for undated references, the most recent edition, including any amendments, is relevant.

IEC 60050-101, International Electrotechnical Vocabulary (IEV) – Part 101: Mathematics

IEC 60050-161, International Electrotechnical Vocabulary (IEV) – Part 161: Electromagnetic compatibility

IEC 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1:

IEC/TR3 61000-2-1, Electromagnetic compatibility (EMC) – Part 2: Environment – Section 1:

Description of the environment – Electromagnetic environment for low-frequency conducted disturbances and signalling in public power supply systems

IEC 61000-3-3, Electromagnetic compatibility (EMC) – Part 3: Limits – Section 3: Limitation of voltage fluctuations and flicker in low-voltage supply systems for equipment with rated current ≤ 16 A

IEC 61000-4-7, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement techniques – Section 7: General guide on harmonics and interharmonics measurements and instrumentation, for power supply systems and equipment connected thereto

IEC 61000-4-15, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement techniques – Section 15: Flickermeter – Functional and design specifications

For the purposes of this part of IEC 61000, the definitions given in IEC 60050-101,

IEC 60050-161 and its amendments 1 and 2, as well as the following, apply.

(electromagnetic) disturbance any electromagnetic phenomenon which, by being present in the electromagnetic environment, can cause electrical equipment to depart from its intended performance

3.1.2 disturbance level the amount or magnitude of an electromagnetic disturbance, measured and evaluated in a specified way

Electromagnetic compatibility (EMC) refers to the ability of a device or system to operate effectively within its electromagnetic environment while not causing intolerable electromagnetic disturbances to other entities in that environment.

Electromagnetic compatibility (EMC) is essential for ensuring that the electromagnetic environment allows all devices, equipment, and systems to operate as intended This is achieved when the level of disruptive emissions is kept low and the immunity levels are sufficiently high.

Electromagnetic compatibility is ensured only when emission and immunity levels are controlled so that the immunity levels of equipment and systems at any point are not exceeded by the disturbance level at that location, which results from the cumulative emissions of all sources and other factors, such as circuit impedance It is conventionally stated that electromagnetic compatibility exists if the probability of deviation from expected performance or the occurrence of disturbed behavior is sufficiently low Refer to Article 4 of IEC 61000-2-1 for more details.

NOTE 3 Lorsque le contexte le rend nécessaire, la compatibilité électromagnétique peut être prise en référence à une seule perturbation ou à une classe de perturbations.

Electromagnetic compatibility refers to the field of study concerning the disrupted behaviors that materials, equipment, or systems experience due to interference from other materials, equipment, or systems, as well as from electromagnetic phenomena.

3.1.4 niveau de compatibilité (électromagnétique) niveau de perturbation électromagnétique spécifié utilisé en tant que niveau de référence dans un environnement spécifié pour la coordination des limites d’émission et d’immunité

NOTE Le niveau de compatibilité électromagnétique est, par convention, choisi de telle sorte que la probabilité de dépassement de ce niveau par les perturbations réelles soit très faible.

The planning level assigned to a specific disturbance in a given environment serves as a reference for establishing applicable emission limits for high-power loads and installations This approach aims to coordinate these limits with all other standards set for equipment intended to connect to the energy distribution network.

The planning level is specific to the location where it is applied and is utilized by the managers responsible for the planning and operation of the energy distribution network in that area Additional details are provided in Appendix A.

PCC (abréviation) point électriquement le plus proche d’une charge particulière, situé sur le réseau public de distribution d’énergie, auquel d’autres charges sont raccordées ou sont susceptibles de l’être

Définitions relatives aux phénomènes

The definitions provided below regarding harmonics are based on the analysis of voltage or current systems using the discrete Fourier transform (DFT) This represents the practical application of the Fourier transform as defined in VEI 101-13-09 Please refer to Appendix B for further details.

The Fourier transform applied to a time function, whether periodic or not, results in a frequency domain representation known as the frequency spectrum of the time function, or simply the spectrum For periodic time functions, the spectrum consists of distinct lines (or components), while for non-periodic time functions, the spectrum is a continuous function that exhibits components across all frequencies.

Additional definitions related to harmonics or inter-harmonics are provided in the VEI and other standards Some of these definitions, while not utilized in the current standard, are included in Annex B.

EMC (abbreviation) the ability of an equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment

Electromagnetic compatibility (EMC) refers to the state of the electromagnetic environment where disturbance emissions are kept at low levels, and immunity levels are sufficiently high This ensures that all devices, equipment, and systems function as intended without interference.

Electromagnetic compatibility is attained when emission and immunity levels are managed to ensure that the disturbance levels from cumulative emissions do not surpass the immunity levels of devices and systems at any given location Compatibility is typically defined by a low probability of deviation from intended performance, as outlined in clause 4 of 61000-2-1.

NOTE 3 Where the context requires it, compatibility may be understood to refer to a single disturbance or class of disturbances.

Electromagnetic compatibility (EMC) refers to the study of how devices, equipment, and systems can adversely affect one another due to electromagnetic phenomena.

(electromagnetic) compatibility level the specified electromagnetic disturbance level used as a reference level in a specified environment for co-ordination in the setting of emission and immunity limits

NOTE By convention, the compatibility level is chosen so that there is only a small probability that it will be exceeded by the actual disturbance level.

Planning level refers to a specific disturbance threshold within a given environment, established as a reference point for setting emission limits from large loads and installations This approach ensures that these limits are coordinated with the standards set for equipment intended to connect to the power supply system.

The planning level is tailored to local specifics and is implemented by the authorities in charge of planning and managing the power supply network in that area For additional details, please refer to Annex A.

PCC (abbreviation) the point on a public power supply network, electrically nearest to a particular load, at which other loads are, or could be, connected

The definitions related to harmonics are derived from analyzing system voltages or currents using the discrete Fourier transform (DFT) method, highlighting its practical application in this context.

Fourier transform as defined in IEV 101-13-09 See annex B.

The Fourier transform converts a time function, whether periodic or non-periodic, into its frequency spectrum For periodic time functions, the spectrum consists of discrete lines, while for non-periodic functions, it forms a continuous function that represents components across all frequencies.

Additional definitions concerning harmonics and interharmonics are provided in the IEV and various standards While some of these definitions are not utilized in this standard, they are explored in annex B.

The fundamental frequency is the reference frequency in the spectrum obtained through the Fourier transform of a time function For the purposes of this standard, the fundamental frequency is equivalent to the frequency of the energy distribution network.

NOTE 1 Dans le cas d’une fonction périodique, la fréquence fondamentale est généralement égale à celle de la fonction elle-même (Voir B.1).

In cases where ambiguity may arise, it is advisable to define the frequency of the power distribution network based on the polarity and rotational speed of the synchronous alternators supplying the system.

3.2.2 composante fondamentale composante dont la fréquence est la fréquence fondamentale

3.2.3 fréquence harmonique fréquence qui est un multiple entier de la fréquence fondamentale Le rapport de la fréquence harmonique à la fréquence fondamentale est nommé rang harmonique (notation recom- mandée: h)

3.2.4 composante harmonique n’importe laquelle des composantes ayant une fréquence harmonique Sa valeur est normalement exprimée en valeur efficace

De faỗon concise, une telle composante peut ờtre simplement dộnommộe ôharmoniqueằ.

3.2.5 fréquence inter-harmonique toute fréquence qui n'est pas un multiple entier de la fréquence fondamentale

NOTE 1 Par extension du rang harmonique, le rang inter-harmonique est le rapport de la fréquence inter- harmonique à la fréquence fondamentale Ce rapport n'est pas un entier (notation recommandée: m).

NOTE 2 Dans le cas ó m < 1, le terme fréquence sous-harmonique peut être également utilisé.

3.2.6 composante inter-harmonique composante dont la fréquence est à une fréquence inter-harmonique Sa valeur est normalement exprimée en valeur efficace

De faỗon concise, une telle composante peut ờtre simplement dộnommộe ôinter-harmoniqueằ.

For the purposes of this standard, as outlined in IEC 61000-4-7, the time window has a width of 10 cycles for 50 Hz networks or 12 cycles for 60 Hz networks, which is approximately 200 ms.

L’intervalle de fréquence entre deux composantes inter-harmoniques consécutives est donc d’environ 5 Hz.

3.2.7 taux de distorsion harmonique total

THD rapport de la valeur efficace de la somme des composantes harmoniques à la valeur efficace de la composante fondamentale La sommation est limitée à un rang défini (notation recommandộe ôHằ).

The fundamental frequency is a key frequency derived from the Fourier transform of a time function, serving as a reference point for all other frequencies in the spectrum In the context of this standard, the fundamental frequency is equivalent to the power supply frequency.

NOTE 1 In the case of a periodic function, the fundamental frequency is generally equal to the frequency of the function itself (See B.1).

Commentaires généraux

The compatibility levels outlined in the following paragraphs pertain to various disturbances considered individually However, in practice, multiple disturbances often occur simultaneously in the electromagnetic environment Specific combinations of these disturbances can impair the performance of certain equipment.

Fluctuations de tension et flicker

In low voltage networks, voltage fluctuations are caused by varying loads, the operation of transformer tap changers, or other functional adjustments within the distribution network and connected equipment.

Under normal conditions, the amplitude of rapid voltage fluctuations is limited to 3% of the nominal supply voltage However, voltage spikes exceeding 3% may occasionally occur in the public distribution network.

De plus, consécutivement à des variations de charge exceptionnelles ou à des manœuvres d’enclenchement, des excursions de la tension en dehors des tolérances de service normales

Voltage fluctuations of approximately ±10% of the declared supply voltage can occur for several seconds until the regulators responsible for high voltage/medium voltage transformers are activated.

In low voltage networks, voltage fluctuations can lead to the occurrence of flicker The severity of flicker is measured according to the IEC 61000-4-15 standards and assessed based on the IEC 61000-3-3 guidelines, taking into account both short-term and long-term effects.

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Q represents either current or voltage

Q 1 is the r.m.s value of the fundamental component h is the harmonic order

Q h is the r.m.s value of the harmonic component of order h

H is generally equal to 50, but equal to 25 when the risk of resonance at higher orders is low.

NOTE THD takes account of harmonics only In the case where interharmonics are to be included, see B.1.2.1.

3.2.8 voltage unbalance (imbalance) a condition in a polyphase system in which the r.m.s values of the line-to-line voltages

The phase angles between consecutive line voltages are not uniform, which is a fundamental aspect of electrical systems This inequality is typically quantified by the ratios of the negative and zero sequence components in relation to the positive sequence component.

NOTE 1 In this standard, voltage unbalance is considered in relation to three-phase systems and negative phase sequence only.

NOTE 2 Several approximations give reasonably accurate results for the levels of unbalance normally encountered

(ratio of negative to positive sequence components), e.g.:

Where U 12 , U 23 and U 31 are the three line-to-line voltages.

The compatibility levels for various disturbances are defined individually; however, equipment performance may be adversely affected by the simultaneous presence of multiple disturbances in the electromagnetic environment For further details, refer to Annex A.

Voltage fluctuations on low voltage networks are produced by fluctuating loads, operation of transformer tap changers and other operational adjustments of the supply system or equipment connected to it.

In normal circumstances the value of rapid voltage changes is limited to 3 % of nominal supply voltage However step voltage changes exceeding 3 % can occur infrequently on the public supply network.

Following significant load changes or switching operations, voltage fluctuations beyond the normal operational tolerances (approximately ±10% of the specified supply voltage) may occur for several seconds until the on-load tap-changers on the high voltage-medium voltage transformers adjust.

Voltage fluctuations in low voltage networks can lead to flicker, which is quantified according to IEC 61000-4-15 and evaluated based on IEC 61000-3-3 The severity of flicker is determined by considering both short-term and long-term effects.

The short-term severity, denoted as P st, is assessed over a 10-minute period Figure 1 illustrates the maximum permissible level of flicker for a standard lamp, resulting from rectangular voltage fluctuations at various repetition rates, corresponding to the threshold P st = 1.

The severity of flicker caused by non-rectangular voltage fluctuations can be assessed either by using a flickermeter or by applying a correction factor specified in IEC 61000-3-3.

La sévérité à long terme, notée P lt , est calculée sur une période de 2 h Elle se déduit des valeurs de P st issues de 12 périodes consécutives de 10 min par la relation:

P P ó P sti (i = 1, 2, , 12) sont 12 valeurs consécutives de P st (voir la CEI 61000-4-15).

Les niveaux de compatibilité sont les suivants: court terme: P st = 1; long terme: P lt = 0,8.

Nombre de variations (rectangulaires) par minute

V ari at ion rel at iv e de tens io n % lampe 230 V lampe 120 V

Figure 1 – Courbe unitaire de sévérité du flicker ( P st = 1) pour des variations rectangulaires de tension sur les réseaux d’alimentation basse tension

Harmoniques

When defining compatibility levels related to harmonics, two key factors must be considered: the increase in the number of disturbing sources and the decrease in purely resistive loads, such as heating, which serve as damping elements in the total load Consequently, we can anticipate a rise in harmonic levels within distribution networks unless harmonic emissions are effectively controlled.

The short-term severity level, represented as P st, is assessed over a 10-minute duration As illustrated in Figure 1, the threshold curve for acceptable flicker in standard lamps is derived from rectangular voltage variations at various repetition rates, with the curve corresponding to P st = 1.

The severity of flicker resulting from non-rectangular voltage fluctuations may be found either by measurement with a flickermeter or by the application of correction factors, as indicated in

The long-term severity level, denoted by P lt , is calculated for a two-hour period It is derived as follows from the values of P st for 12 consecutive 10-minute periods.

P P where P sti (i = 1, 2 12) are 12 consecutive values of P st (See IEC 61000-4-15)

Compatibility levels are as follows: short-term: P st = 1; long-term: P lt = 0,8.

Number of voltage changes (rectangular) per minute

Rel at iv e vo ltage c hange %

Figure 1 – Flicker - Curve of equal severity ( P st = 1) for rectangular voltage changes on LV power supply systems.

When determining compatibility levels for harmonics, it is essential to consider the growing number of harmonic sources and the declining percentage of purely resistive loads, such as heating loads, which act as damping elements Consequently, it is anticipated that harmonic levels in power supply systems will rise until effective limits are established for the sources of harmonic emissions.

The compatibility levels outlined in this document should be interpreted as pertaining to stationary or quasi-stationary states They are provided as reference values for long-term effects and for very short-term effects.

– Les effets à long terme concernent principalement les conséquences thermiques sur les câbles, les transformateurs, les moteurs, les condensateurs, etc Ils proviennent de niveaux harmoniques maintenus pendant 10 min ou plus.

Short-term effects primarily involve the disruption of electronic devices that may be sensitive to harmonic levels sustained for 3 seconds or less Transient conditions are not included in these effects.

The compatibility levels for individual harmonic voltages concerning long-term effects are presented in Table 1 The compatibility level associated with the total harmonic distortion rate is THD = 8%.

Tableau 1 – Niveaux de compatibilité pour les tensions harmoniques individuelles dans les réseaux basse tension (valeurs efficaces en pourcentage de la valeur efficace de la composante fondamentale)

Harmoniques impairs non multiples de 3

The specified levels for odd harmonics that are multiples of three apply to homopolar harmonics In a three-phase network without a neutral conductor or in the absence of a load connected between a phase and the ground, the values of the 3rd and 9th harmonics can be significantly lower than the compatibility levels, depending on the imbalance of the network.

In terms of very short-term effects, the compatibility levels of the individual harmonic components of the voltage are equal to the values provided in Table 1, multiplied by a coefficient \( k \) calculated as described below.

Pour le taux de distorsion harmonique total, le niveau de compatibilité correspondant est

The compatibility levels mentioned above also apply to switching notches, as they contribute to the harmonic content of the power supply voltage However, regarding their other effects, including their impact on the switching of other converters and their influence on equipment operating at higher spectrum ranges, a temporal domain description is necessary, as outlined in the corresponding product standard.

Inter-harmoniques

L’état des connaissances concernant perturbations électromagnétiques impliquées dans les inter-harmoniques est toujours en développement Voir l’annexe B pour une discussion plus approfondie.

The compatibility levels outlined in this standard pertain to quasi-stationary or steady-state harmonics, serving as reference values for both long-term and very short-term effects.

– The long-term effects relate mainly to thermal effects on cables, transformers, motors, capacitors, etc They arise from harmonic levels that are sustained for 10 min or more.

– Very short-term effects relate mainly to disturbing effects on electronic devices that may be susceptible to harmonic levels sustained for 3 seconds or less Transients are not included.

The compatibility levels for individual harmonic components of voltage, as outlined in Table 1, indicate the long-term effects on system performance Notably, the total harmonic distortion (THD) is measured at 8%.

Table 1 – Compatibility levels for individual harmonic voltages in low voltage networks

(r.m.s values as percent of r.m.s value of the fundamental component)

Odd harmonics non-multiple of 3

The levels for odd harmonics that are multiples of three are applicable to zero sequence harmonics In a three-phase network lacking a neutral conductor or load between the line and ground, the values of the 3rd and 9th harmonics can be significantly lower than the compatibility levels, influenced by the system's unbalance For specific ranges, the equations are as follows: for \(17 \leq h \leq 49\), the formula is \(2.27 \times (17/h) - 0.27\); for \(21 < h \leq 45\), the value is \(0.2\); and for \(10 \leq h \leq 50\), it is \(0.25 \times (10/h) + 0.25\).

The compatibility levels for individual harmonic components of the voltage, pertaining to very short-term effects, are determined by multiplying the values presented in Table 1 by a factor \( k \), which is calculated using a specific formula.

The corresponding compatibility level for the total harmonic distortion is THD = 11 %.

Commutation notches impact harmonic levels in the supply voltage, as outlined by the compatibility levels However, to understand their additional effects—such as their influence on the commutation of other converters and their impact on equipment related to higher-order harmonic components—a time-domain description is necessary, as specified in the relevant product standard.

Knowledge of the electromagnetic disturbance involved in interharmonic voltages is still developing See annex B for further discussion.

The current standard specifies compatibility levels only for inter-harmonic voltages at frequencies close to the fundamental frequency (50 Hz or 60 Hz), which results in modulation of the supply voltage amplitude.

In this case, certain loads sensitive to the square of the voltage, particularly lighting systems, exhibit a flicker phenomenon This flicker is characterized by a beating frequency, which is the difference between the frequencies of the two coexisting voltages, namely the fundamental frequency and the inter-harmonic frequency.

The compatibility level of an individual inter-harmonic voltage, represented as the ratio of the amplitude of inter-harmonic to fundamental voltages, is illustrated in Figure 2 as a function of beat frequency This analysis, similar to section 4.2, is based on a flicker severity level of P st = 1 for 120 V and 230 V lamps Measurements frequently indicate the presence of multiple inter-harmonics.

Fréquence de battement Hz (différence entre les deux fréquences mises en jeu) A m pl itude de l'i nt erharm oni que ( % de la tensi on fondam ent al e) lampe 120 V lampe 230 V

Figure 2 – Niveaux de compatibilité pour les tensions inter-harmoniques liées au flicker (effet de battement)

NOTE 1 Une situation semblable peut apparaợtre lorsqu’une tension harmonique d’amplitude significative

Particularly for orders 3 or 5, the phenomenon coincides with an inter-harmonic voltage of a nearby frequency In this case, it is important to evaluate the phenomenon according to Figure 2, using the product of the relative amplitudes of the harmonic and inter-harmonic voltages that create the beat frequency as the amplitude However, the result is rarely significant.

Below the inter-harmonic range of 0.2, compatibility levels are determined by similarity to flicker requirements It is recommended that flicker severity be calculated according to Annex A of IEC 61000-3-7, using the provided form factor for sinusoidal periodic voltage fluctuations A conservative approach suggests setting the form factor value at 0.8 for the range of 0.04 < m ≤ 0.2 and at 0.4 for m ≤ 0.04.

Creux de tension et coupures brèves

Ces phénomènes sont présentés à l’annexe B ainsi que dans la CEI 61000-2-8.

This standard specifies compatibility levels exclusively for interharmonic voltages that occur near the fundamental frequency of 50 Hz or 60 Hz, leading to amplitude modulation of the supply voltage.

Under specific conditions, loads sensitive to the square of the voltage, particularly lighting devices, can experience a beat effect that leads to flickering This flicker occurs due to the beat frequency, which is the difference between the interharmonic and fundamental frequencies of the coincident voltages.

The compatibility level of a single interharmonic voltage, represented as the ratio of its amplitude to the fundamental frequency, is illustrated in Figure 2 as a function of the beat frequency This analysis, similar to section 4.2, is based on a flicker level of P st = 1 for lamps operating at 120 V.

230 V (Measurements often show several interharmonics to be present).

Beat frequency Hz (difference between the two combining frequencies)

In te rharm oni c am pl itude ( % o f f undam ent al v ol tage)

Figure 2 – Compatibility level for interharmonic voltages relating to flicker (beat effect)

NOTE 1 A similar situation is possible when there is an appreciable level of voltage at a harmonic frequency

Interharmonic voltages, especially those of order 3 or 5, can coincide with nearby frequencies, necessitating an assessment of their effects as illustrated in figure 2 The amplitude resulting from this interaction is determined by the product of the relative amplitudes of the harmonic and interharmonic voltages, which produce the beat frequency However, the overall impact is typically minimal.

Interharmonic order 0.2 compatibility levels are established based on similar flicker requirements To determine flicker severity, calculations should follow annex A of IEC 61000-3-7, utilizing the shape factor designated for periodic and sinusoidal voltage fluctuations The conservative shape factor value is set at 0.8.

4.5 Voltage dips and short supply interruptions

For a discussion of these phenomena, see annex B and IEC 61000-2-8.

Déséquilibre de tension

This standard only considers voltage imbalance in terms of long-term effects, specifically over a duration of 10 minutes or more It focuses solely on voltage imbalance concerning the negative sequence component, which is relevant when examining potential interference with equipment connected to low-voltage distribution networks.

NOTE Pour les réseaux ó le point neutre est directement relié à la terre, le taux de déséquilibre homopolaire peut également être approprié.

The voltage imbalance caused by a single-phase load connected between two phases is nearly equal to the ratio of the power of that load to the short-circuit power of the three-phase network.

The compatibility level is inversely related, equating to 2% of the direct component Values can reach up to 3%, particularly in areas where connecting high single-phase loads is common.

Surtensions transitoires

Ces phénomènes sont présentés à l’annexe B.

Due to the variations in amplitude and energy of transient overvoltages from different sources, primarily lightning and switching operations, no specific compatibility level is defined For isolation coordination, refer to IEC 60664-1.

Variations temporaires de la fréquence du réseau

In public power networks, the frequency is maintained as close as possible to its nominal value, primarily depending on the size of the interconnected electrical systems Typically, the frequency variation range is less than 1 Hz When a synchronous interconnection spans a continent, the fluctuations are usually much smaller However, island networks that are not synchronously connected to a larger system may experience more significant frequency variations.

Le niveau de compatibilité relatif aux variations temporaires de fréquence est fixé à ±1 Hz.

En régime permanent, l’écart entre la fréquence et la fréquence nominale est beaucoup plus faible.

NOTE Pour certains équipements, la vitesse d’évolution de la fréquence est importante.

Composantes continues

On public power supply networks covered by this standard, the voltage typically does not contain a significant direct current component However, this can occur in the presence of loads that draw asymmetrical currents Uncontrollable events, such as geomagnetic storms, are excluded from consideration.

The critical magnitude refers to the level of direct current The value of direct voltage is influenced not only by the direct current but also by other factors, particularly the resistance of the network at the specified point Consequently, no compatibility level is defined for the direct voltage level Please refer to Appendix B for more details.

This standard addresses voltage unbalance by focusing on long-term effects lasting 10 minutes or more It specifically examines the negative phase sequence component, which is crucial for understanding potential interference with equipment linked to public low voltage distribution systems.

NOTE For systems with the neutral point directly connected to earth, the zero-sequence unbalance ratio can be relevant.

Voltage unbalance from a single-phase load connected line-to-line is effectively represented by the ratio of the load power to the three-phase short circuit power of the network.

The compatibility level for unbalance is defined as a negative sequence component of 2% of the positive sequence component In certain regions, particularly where large single-phase loads are commonly connected, this value can rise to as much as 3%.

For a discussion of these phenomena, see annex B.

Transient overvoltages, such as those caused by lightning and switching surges, exhibit significant differences in amplitude and energy content, leading to the absence of a specified compatibility level For guidance on insulation coordination, refer to IEC 60664-1.

In public power supply systems, maintaining the frequency close to the nominal value is crucial, with variations typically within 1Hz for interconnected systems On a continental scale, synchronous interconnections result in even smaller frequency fluctuations However, island systems that are not connected to larger networks may experience greater frequency variations.

The compatibility level for the temporary variation of frequency from the nominal frequency is ±1 Hz.

The steady-state deviation of frequency from the nominal frequency is much less.

NOTE For some equipment the rate of change of frequency is significant.

Public power supply systems typically do not exhibit a significant direct current (d.c.) component; however, this can occur when specific non-symmetrically controlled loads are connected It is important to note that uncontrollable events, such as geomagnetic storms, are not considered in this context.

The critical factor in determining d.c voltage is the level of d.c current, which is influenced by various elements, particularly the resistance of the network at the relevant point Consequently, a specific compatibility level for d.c voltage cannot be established For further details, refer to annex B.

Systèmes de transmission de signaux sur le réseau

Public networks primarily serve to supply electricity to customers, but network managers also utilize them for signal transmission, such as controlling specific types of loads These networks are not intended for signal transmission between private users.

Technically, remote control systems involve an inter-harmonic voltage source, as detailed in section 4.4 and Appendix B In this context, the signaling voltage is intentionally transmitted over a specific section of the network Both the frequency and voltage of the emitted signal are predetermined, and the signal is broadcasted at designated times.

It is essential to consider the signal voltage levels of remote controls to ensure the immunity of equipment connected to the networks on which these signals are transmitted.

La conception d’un système de transmission de signaux sur le réseau doit répondre à trois contraintes:

– assurer la compatibilité entre installations voisines;

– éviter les interférences entre le système de transmission de signaux et ses éléments et les équipements raccordés au réseau ou faisant partie du réseau;

– empêcher le système de transmission de signaux de perturber les équipements raccordés au réseau ou faisant partie du réseau.

Quatre systèmes de transmission de signaux sur le réseau sont décrits à l’article 10 de la

CEI 61000-2-1 (Les plages de fréquences mentionnées sont des valeurs nominales; elles relèvent de la pratique).

4.10.2 Système de télécommande centralisée (de 110 Hz à 3 000 Hz)

Centralized remote control signals are transmitted as a series of pulses, with each pulse lasting between 0.1 seconds and 7 seconds The total duration of the sequence ranges from 6 seconds to 180 seconds, and typically, a single pulse lasts about

0,5 s et la séquence une durée d’environ 30 s.

These systems typically operate within a frequency range of 110 Hz to 3,000 Hz The amplitude of the injected sinusoidal signals is generally between 2% and 5% of the nominal supply voltage, depending on local practices Resonance phenomena can lead to amplification levels of up to 9% In the most recently installed systems, the signals are usually between 110 Hz and 500 Hz.

In certain countries, the so-called Meister curve, illustrated in Figure 3, is officially recognized When the Meister curve is not utilized, the amplitude of signals emitted within this frequency range should not exceed the levels specified in Table 1 for odd harmonics (non-multiples of 3).

Public networks are primarily designed to supply electric energy to customers, but they also facilitate the transmission of signals for network management, including load control However, these networks are not utilized for signal transmission between private users.

Mains signalling serves as a source of interharmonic voltages, as detailed in section 4.4 and annex B In this context, the signal voltage is deliberately applied to a specific section of the supply system Both the voltage and frequency of the emitted signal are predetermined, and the transmission occurs at designated times.

For co-ordination of the immunity of equipment connected to networks on which mains signals exist, the voltage levels of these signals need to be taken into account.

The design of mains signalling systems should meet three objectives:

– to assure compatibility between neighbouring installations;

– to avoid interference with the mains signalling system and its elements by equipment on or connected to the network;

– to prevent the mains signalling system from disturbing equipment on or connected to the network.

Four types of mains signalling systems are described in clause 10 of IEC 61000-2-1 (The frequency ranges mentioned are nominal and are a matter of common practice).

4.10.2 Ripple control systems (110 Hz to 3 000 Hz)

Ripple control signals are sent as a series of pulses, typically lasting around 0.5 seconds each, with the entire sequence lasting between 6 to 180 seconds, commonly around 30 seconds.

These systems typically function within a frequency range of 110 Hz to 3000 Hz, with the injected sine wave signal generally set between 2% and 5% of the nominal supply voltage, although resonance may elevate this to 9% In newer installations, the signal frequencies are commonly found between 110 Hz and 500 Hz.

In certain countries, the Meister curve, illustrated in figure 3, is officially acknowledged In regions where the Meister curve is not utilized, the amplitudes of injected signals must remain below the specified levels for odd harmonics, as outlined in table 1.

Ni veau du si gnal : U s / U n %

Figure 3 – Courbe ôde Meisterằ pour les systốmes de tộlộcommande centralisée dans les réseaux publics (100 Hz à 3 000 Hz)

4.10.3 Systèmes de courants porteurs en ligne moyenne fréquence (de 3 kHz à 20 kHz)

4.10.4 Systèmes de courants porteurs en ligne radiofréquence (de 20 kHz à 148,5 kHz)

Due to the highly heterogeneous characteristics of various systems, no general recommendations can be provided It is the responsibility of manufacturers to ensure compatibility between their systems and the power network.

Figure 3 – Meister curve for ripple control systems in public networks

4.10.3 Medium-frequency power-line carrier systems (3 kHz to 20 kHz)

4.10.4 Radio-frequency power-line carrier systems (20 kHz to 148,5 kHz)

Due to the unique characteristics of different systems, manufacturers must ensure compatibility between their systems and the supply network, as no universal guidance can be provided.

Le rôle des niveaux de compatibilité et de planification en CEM

Le besoin de niveaux de compatibilité

Electromagnetic compatibility (EMC) addresses the potential degradation of performance in electrical or electronic equipment due to disturbances in the electromagnetic environment where the equipment operates Two essential conditions must be met to ensure compatibility.

– il est nécessaire que l’émission de perturbations dans l’environnement électromagnétique soit maintenue en dessous du niveau qui conduirait à une dégradation inacceptable des performances du matériel fonctionnant dans cet environnement;

– il est nécessaire que tout matériel fonctionnant dans l’environnement électromagnétique possède une immunité suffisante à toutes les perturbations, pour les niveaux qui sont les leurs dans l’environnement.

Emission limits and immunity requirements are interdependent Effectively controlling emissions allows for less stringent immunity standards for equipment Conversely, if the equipment is highly immune to disturbances, there is no need for very strict emission limits.

Il est donc nécessaire de bien coordonner les limites d’émission et d’immunité C’est la principale fonction des niveaux de compatibilité indiqués dans cette norme.

The disturbances in question involve phenomena occurring on low-voltage public distribution networks These supply networks, responsible for transporting electrical energy from production plants to consumer equipment, inadvertently also carry electromagnetic disturbances from their sources to sensitive devices.

Trois facteurs ont été pris en compte lors de la définition des niveaux de compatibilité relatifs aux différents phénomènes:

The compatibility level refers to the degree of disturbance that may occur in the environment, with a low probability of exceeding 5% For certain disturbances, observed levels are increasing, highlighting the need for a long-term perspective.

– il s’agit d’un niveau de perturbation qui peut être maintenu en appliquant des règles réalistes de limitation des émissions;

– il s’agit du niveau de perturbation auquel un matériel fonctionnant dans l’environnement correspondant nécessite d’être immunisé, avec une marge convenable.

Relation entre niveau de compatibilité et niveaux d’immunité

For each phenomenon, it is essential to assess the compatibility level in relation to the potential disturbances that may arise in the corresponding environment Any equipment designed to operate within this environment must possess immunity that is equal to or greater than the identified disturbance level Typically, an appropriate margin is maintained between the compatibility and immunity levels of the equipment in question.

The function of compatibility levels and planning levels in EMC

A.1 The need for compatibility levels

Electromagnetic compatibility (EMC) addresses the potential performance degradation of electrical and electronic equipment caused by disturbances in the surrounding electromagnetic environment To ensure compatibility, two key requirements must be met.

– the emission of disturbances into the electromagnetic environment must be maintained below a level that would cause an unacceptable degradation of the performance of equipment operating in that environment;

– all equipment operating in the electromagnetic environment must have sufficient immunity from all disturbances at the levels at which they exist in the environment.

Emission limits and immunity requirements are interdependent; effective emission control reduces the need for strict immunity standards on equipment Conversely, highly immune equipment allows for more lenient emission limits.

There is a requirement, therefore, for close co-ordination between the limits adopted for emission and immunity That is the principal function of the compatibility levels specified in this standard.

The article discusses disturbance phenomena in low voltage networks of public alternating current (a.c.) power supply systems It highlights that while these systems are designed to transmit electrical energy from generating stations to end-use equipment, they inadvertently also serve as pathways for electromagnetic disturbances from their sources to the affected equipment.

Three considerations have been borne in mind in setting the compatibility level for each phenomenon:

The compatibility level refers to the expected disturbance in the environment, with a small probability of exceeding 5% As the severity of certain disturbance phenomena increases, a long-term perspective becomes essential.

– it is a disturbance level which can be maintained by implementing practicable limits on emissions;

– it is the level of disturbance from which, with a suitable margin, equipment operating in the relevant environment must have immunity

A.2 Relation between compatibility level and immunity levels

It is essential to identify the compatibility level of disturbance phenomena, which indicates the severity that can occur in a specific environment All equipment designed for use in that environment must possess immunity that meets or exceeds this disturbance level Typically, a margin is established between the compatibility and immunity levels, tailored to the specific equipment involved.

Additionally, compatibility levels have been established for disturbances, assessed individually, and for harmonics and inter-harmonics at specific frequencies In practice, it is important to recognize that multiple disturbances often coexist in the environment, and the performance of certain equipment may be compromised by a specific combination of disturbances, even if each one is below the corresponding compatibility level.

For instance, in the case of harmonics and inter-harmonics, specific combinations of frequencies, amplitudes, and phases can significantly alter the peak value of the voltage and/or its zero-crossing point The presence of additional disturbances can further complicate the situation.

Dans la mesure ó le nombre de combinaisons possibles est infini, il est impossible de fixer des niveaux de compatibilité pour les combinaisons de perturbations.

If a combination of disturbances exists that leads to a degradation of a product's performance, it is essential to identify this combination so that the product's immunity can be specified accordingly.

Relation entre niveau de compatibilité et limites d’émission

It is important to note that certain disturbances originate from atmospheric phenomena, such as lightning, or from the normal and inevitable response of a well-designed power network to electrical faults or the activation of specific loads and equipment This category includes transient overvoltages, voltage sags, and brief power interruptions No emission limits can be defined for these phenomena since the sources of disturbance are uncontrollable In this context, compatibility levels reflect the severity of disturbances that can be expected in practice.

Many disturbances originate from electrical applications connected to the public grid, or to a lesser extent, from the network equipment itself These disturbances occur when such devices draw a current that is not a constant or regular function of the supply voltage, but instead exhibits sudden variations or fails to follow the complete cycle of the voltage waveform.

Ces courants déformés circulent à travers les impédances du réseau d’alimentation et engendrent des déformations analogues sur la tension.

Although reducing network impedance is sometimes necessary to mitigate the effects of specific disturbance sources, these impedances are often determined based on factors such as voltage regulation and other considerations unrelated to disturbance attenuation.

Tension deformations are transmitted to other equipment, some of which are sensitive to these changes The disturbance levels at the terminals of this equipment depend on the type, number, and location of the disturbing devices operating at any given moment, as well as how the disturbances from various sources combine to create specific disturbance levels at particular locations It is essential that these levels remain below compatibility thresholds.

The relationship between compatibility levels and emission limits is more complex than that between compatibility levels and immunity levels This complexity arises from the diverse sources of disturbances and, particularly in the case of low-frequency disturbances, the limits set for each source consider the cumulative effects of emissions from multiple similar sources It is the resulting disturbance level that is compared to the compatibility level Additionally, many emission limits are expressed in current, while compatibility levels are predominantly expressed in voltage for most disturbances, necessitating the consideration of network impedance.

Compatibility levels have been established for various disturbance phenomena, including specific frequencies for harmonics and interharmonics It is important to acknowledge that multiple disturbance phenomena often coexist in the environment, and certain combinations of these disturbances can negatively impact the performance of equipment, even if each disturbance is below the defined compatibility level.

Harmonics and interharmonics can significantly impact voltage peaks and zero crossing points due to specific combinations of frequency, magnitude, and phasing Additionally, the presence of other disturbances can further complicate these effects.

Because the number of permutations is infinite, it is not possible to set compatibility levels for combinations of disturbances.

To ensure optimal product performance, it is essential to identify any combinations of disturbances within the compatibility levels that may degrade its functionality This identification allows for the appropriate consideration of the product's immunity requirements.

A.3 Relation between compatibility level and emission limits

Some disturbances originate from atmospheric phenomena, particularly lightning, or from the natural responses of a well-designed supply system to electrical faults or load switching Key disturbances include transient overvoltages, voltage dips, and short supply interruptions Emission limits cannot be established for these phenomena due to the uncontrollable nature of their sources Therefore, the compatibility level is designed to indicate the expected severity of these disturbances in practical scenarios.

Many disturbances in public electricity supply originate from the equipment used to utilize the power, as well as, to a lesser extent, from the supply system itself These disturbances occur when the equipment draws an irregular current that does not consistently align with the supplied voltage, leading to abrupt variations or incomplete cycles of the voltage waveform Consequently, these irregular currents pass through the supply network's impedances, resulting in voltage irregularities.

While reducing certain network impedances can help alleviate specific disturbances, they are typically fixed due to voltage regulation and other factors unrelated to disturbance mitigation.

Voltage irregularities can disrupt other equipment, with the severity of the disturbance influenced by the types and locations of emission sources, as well as their operational status It is crucial that these disturbance levels remain within acceptable compatibility limits.

Emission limits are intricately related to compatibility levels, as they involve a diverse range of sources Particularly for low-frequency disturbances, each source contributing to the overall environmental disturbance level is just one among many Additionally, while emission limits are typically defined in terms of current, compatibility levels are often expressed in voltage, necessitating the consideration of network impedances.

However, the implementation of emission limits ensures that the actual level of disturbance will not exceed the compatibility threshold, except in the unlikely cases accepted in EMC.

Emission limits for a specific type of equipment cannot be established in isolation; they must be coordinated with the limits set for all other equipment contributing to the same disturbance It is crucial that this coordination ensures that when all sources comply with their individual limits and operate simultaneously under normal conditions for the corresponding environment, the resulting disturbance level remains below the compatibility threshold.

Les sources de perturbations sont extrêmement variées, mais il est utile de les diviser en deux grandes catégories:

Niveaux de planification

In the context of high-power installations and loads, the power supply network managers play a crucial role They utilize the concept of planning level to establish the applicable emission limits for these installations.

Planning levels primarily apply to medium and high voltage networks However, low-frequency conducted disturbances propagate to both low voltage networks and higher voltage levels Therefore, emission limit coordination will consider all voltage levels.

The goal of establishing emission limits is to guarantee that actual disturbance levels remain within acceptable compatibility thresholds, excluding low-probability events that are deemed acceptable.

Emission limits for specific equipment cannot be set in isolation; they must be coordinated with limits for all other sources of the same disturbance phenomenon This coordination ensures that when all sources adhere to their individual limits and operate together as expected in the relevant environment, the overall disturbance level remains below the established compatibility level.

The sources of emission are extremely diverse, but it is useful to divide them into two broad categories:

Large equipment and installations were historically the primary sources of low-frequency emissions, including harmonics and voltage fluctuations It is crucial for electricity suppliers to be informed about these emissions, allowing them to collaborate with the equipment operators or owners to establish an operating regime that keeps emissions within acceptable limits This partnership also enables the development of a supply method that minimizes the risk of disturbances to other equipment connected to the network, with solutions tailored to the specific location.

Small equipment, which is increasingly prevalent in domestic, commercial, and smaller industrial settings, is a significant source of low-frequency disturbances This equipment is often purchased without consulting electricity suppliers and is typically installed and operated independently While emissions from individual devices may be minimal, the sheer number of units can contribute to up to 50% of system demand Additionally, many of these devices emit relatively high levels of disturbances compared to their rated power Consequently, this type of equipment has emerged as a major and growing contributor to low-frequency disturbances To effectively manage these emissions, it is essential to design and manufacture equipment in accordance with established emission limits.

To ensure accurate representation of the maximum potential disturbance in the electromagnetic environment, it is essential to harmonize the emission limits for a diverse array of products This includes both large installations reported to the electricity supplier and smaller devices that users choose to install independently.

Electricity suppliers may identify installations that include numerous low-power professional devices In such instances, emissions are evaluated based on the overall installation rather than setting limits on each individual piece of equipment.

In managing large loads and installations, those in charge of the power supply system play a crucial role They utilize the concept of planning level, as outlined in section 3.1.5, to establish suitable emission limits for these installations.

Planning levels are relevant primarily to medium voltage and higher voltage networks.

Low frequency conducted disturbances can travel in both directions between low voltage and higher voltage networks Therefore, it is essential to consider all voltage levels when coordinating emission limits.

L’utilisation des niveaux de planification est décrite dans les rapports techniques

CEI/TR3 61000-3-6 et CEI/TR3 61000-3-7 Les points les plus importants sont les suivants.

The planning level is a value determined by the entity responsible for the planning and operation of the power network in a specific area It is utilized to establish emission limits applicable to installations and high-power loads that need to be connected to the network in that region This approach aids in distributing the right to disrupt as equitably as possible.

The planning level will be lower than the compatibility level, typically maintaining a margin between these two levels based on factors such as the type of disturbance, the design and maintenance of the power network, existing disturbance levels, the potential for resonance, and load profiles Therefore, it is dependent on the specific point of consideration.

While high-power facilities and equipment are primarily associated with planning levels, it is crucial to consider the numerous other disruptive sources, particularly the many low-power devices connected at low voltage The available margin to tolerate emissions from high-power installations practically depends on the effectiveness of the limits set for low-power devices Any challenges in this area indicate the need for stricter emission regulations for low-power devices The main objective is to ensure that the anticipated level of disturbance does not exceed the compatibility level.

Composantes continues

Tiêu đề	IEC 61000-2-2 2002
Trường học	University of Electric and Electronic Engineering
Chuyên ngành	Electromagnetic Compatibility
Thể loại	Standards Document
Năm xuất bản	2002
Thành phố	Geneva

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