WG 8 - TC 77/SC 77A/WG 8

IEC TR 61000-2-15: 2023 which is a Technical Report, addresses in particular the following main phenomena, which affect the power quality in modern distribution systems with high penetration of power electronics converters. As some aspects of the subject have already been addressed in the past, considering the evolution of the LV and MV networks, this document focuses on the following aspects:
resonances in the network, modelling and on-site validation;
supraharmonics and measurements issues;
impact of increased number of power electronic converters;
stability and instability issues for the equipment to be connected
The target phenomena and conditions of this document are the following:
frequency: ≤ 2 kHz, 2 kHz to 9 kHz, ≥ 9 kHz;
voltage levels: LV, MV;
harmonic sources: all types of converters (EV battery chargers, appliances, etc.…).
Some of these frequency ranges have already been standardized in some countries (Japan, Germany, Switzerland, etc.), but the resulting phenomena developed will benefit being described in more details, with a focus on the interaction between the converters and the electrical networks. The case of the presence of a large number of converters is also at stake. Some complex phenomena can also arise when the full system is not stable anymore. NOTE Whereas it is expected that the models and derived calculations form this document can be applied to the Americas electrical systems its formal validation studies are still pending.

IEC TR 61000-3-14:2011 is a Technical Report which provides guidance on principles that can be used as the basis for determining the requirements for the connection of disturbing installations to low voltage (LV) public power systems. For the purposes of this part of IEC 61000, a disturbing installation means an installation (which may be a load or a generator) that produces disturbances: harmonics and/or interharmonics, voltage flicker and/or rapid voltage changes, and/or voltage unbalance. The primary objective is to provide guidance to system operators or owners for engineering practices, which will facilitate the provision of adequate service quality for all connected customer installations. In addressing installations, this report is not intended to replace equipment standards for emission limits. This report addresses the allocation of the capacity of the system to absorb disturbances. It does not address how to mitigate disturbances, nor does it address how the capacity of the system can be increased.

This part of IEC 61000 provides guidance on principles which can be used as the basis for determining the requirements for the connection of fluctuating installations to MV, HV and EHV public power systems (LV installations are covered in other IEC documents). For the purposes of this report, a fluctuating installation means an installation (which may be a load or a generator) that produces voltage flicker and / or rapid voltage changes. The primary objective is to provide guidance to system operators or owners on engineering practices which will facilitate the provision of adequate service quality for all connected customers. In addressing installations, this document is not intended to replace equipment standards for emission limits. This report addresses the allocation of the capacity of the system to absorb disturbances. It does not address how to mitigate disturbances, nor does it address how the capacity of the system can be increased. Since the guidelines outlined in this report are necessarily based on certain simplifying assumptions, there is no guarantee that this approach will always provide the optimum solution for all flicker situations. The recommended approach should be used with flexibility and engineering judgment as far as engineering is concerned, when applying the given assessment procedures in full or in part. The system operator or owner is responsible for specifying requirements for the connection of fluctuating installations to the system. The fluctuating installation is to be understood as the customer's complete installation (i.e. including fluctuating and non fluctuating parts). Problems related to voltage fluctuations fall into two basic categories:
- Flicker effect from light sources as a result of voltage fluctuations;
- Rapid voltage changes even within the normal operational voltage tolerances are considered as a disturbing phenomenon.
The report gives guidance for the coordination of the flicker emissions between different voltage levels in order to meet the compatibility levels at the point of utilisation. This report primarily focuses on controlling or limiting flicker, but a clause is included to address the limitation of rapid voltage changes. This second edition cancels and replaces the first edition published in 1996 and constitutes a technical revision. This new edition is significantly more streamlined than the original technical report (Edition 1), and reflects the experiences gained in the application of the first edition. This technical report has also been harmonised with IEC/TR 61000-3-6 and IEC/TR 61000-3-13. This Technical Report has the status of a basic EMC publication in accordance with IEC Guide 107.

This part of IEC 61000 provides guidance on principles which can be used as the basis for determining the requirements for the connection of unbalanced installations (i.e. three-phase installations causing voltage unbalance) to MV, HV and EHV public power systems (LV installations are covered in other IEC documents). For the purposes of this report, an unbalanced installation means a three-phase installation (which may be a load or a generator) that produces voltage unbalance on the system. The connection of single-phase installations is not specifically addressed, as the connection of such installations is under the control of the system operator or owner. The general principles however may be adapted when considering the connection of single-phase installations. The primary objective is to provide guidance to system operators or owners on engineering practices, which will facilitate the provision of adequate service quality for all connected customers. In addressing installations, this document is not intended to replace equipment standards for emission limits. The report addresses the allocation of the capacity of the system to absorb disturbances. It does not address how to mitigate disturbances, nor does it address how the capacity of the system can be increased. Since the guidelines outlined in this report are necessarily based on certain simplifying assumptions, there is no guarantee that this approach will always provide the optimum solution for all unbalanced load situations. The recommended approach should be used with flexibility and judgment as far as engineering is concerned, when applying the given assessment procedures in full or in part. The system operator or owner is responsible for specifying requirements for the connection of installations which may cause unbalance on the system. The disturbing installation is to be understood as the complete customer's installation (i.e. including balanced and unbalanced parts). Problems related to unbalance fall into two basic categories.
- Unbalanced installations that draw negative-sequence currents which produce negative-sequence voltages on the supply system. Examples of such installations include arc furnaces and traction loads (typically connected to the public network at HV), and three phase installations where the individual loads are not balanced (typically connected at MV and LV). Negative-sequence voltage superimposed onto the terminal voltage of rotating machines can produce additional heat losses. Negative-sequence voltage can also cause non-characteristic harmonics (typically positive-sequence 3rd harmonic) to be produced by power converters.
- Unbalanced installations connected line-to-neutral can also draw zero-sequence currents which can be transferred or not into the supply system depending on the type of connection of the coupling transformer. The flow of zero-sequence currents in a grounded neutral system causes zero-sequence unbalance affecting line-to-neutral voltages. This is not normally controlled by setting emission limits, but rather by system design and maintenance. Ungrounded-neutral systems and phase-to-phase connected installations are not, however, affected by this kind of voltage unbalance. This report gives guidance only for the coordination of the negative-sequence type of voltage unbalance between different voltage levels in order to meet the compatibility levels at the point of utilisation. No compatibility levels are defined for zero-sequence type of voltage unbalance as this is often considered as being less relevant to the coordination of unbalance levels compared to the first type of voltage unbalance. However, for situations where a non-zero impedance exists between neutral and earth with the system still being effectively grounded (i.e., where the ratio between zero-sequence, X0 and positive sequence reactance X1 is 0 < X0/X1 = 3), this type of voltage unbalance can be of concern especially when the type of connection of the co

IEC TR 61000-2-14:2006 Describes the electromagnetic environment with respect to the voltages in excess of normal that are found on electricity supply networks operating at low and medium nominal voltages and that can be impressed on equipment connected to those networks, without considering further effects (e.g. amplification or attenuation) within an installation. Since these overvoltages have the potential to hinder the functioning of electrical and electronic equipment, they fall within the definition of electromagnetic disturbance in the field of EMC. Various categories of overvoltage are described, based on relative magnitude, duration and energy content. This Technical Report describes the phenomena of overvoltages, it does not specify compatibility levels and does not directly specify emission and immunity levels. The report describes the various phenomena and processes that cause overvoltages, including the transfer into the networks concerned of overvoltages that originate in or traverse other networks and installations, including higher voltage networks and the installations of electricity users. The effects of overvoltages on equipment are outlined. Some case studies of overvoltage events are presented. Recommendations are made regarding the general technical approach to mitigating the risk of equipment being hindered from operating as intended by the effects of overvoltages. (It is not the function of IEC publications to assign responsibility for mitigating measures to any of the parties involved.) The purpose of this report is to ensure that this important category of electromagnetic disturbance is included in the description of the environment in Part 2 of IEC 61000. For that purpose, only a brief description is provided of the various overvoltages and their causes and effects. A much more detailed treatment can be found in IEC 62066. A UIE publication - Guide to quality of electrical supply for industrial installations, Part VI: Transient and temporary overvoltages and currents - has a similar content. Measurement methods are specified in IEC 61000-4-30.

This part of IEC 61000 is concerned with conducted disturbances in the frequency range from 0 kHz to 9 kHz, with an extension up to 148,5 kHz specifically for mains signalling systems. Compatibility levels are specified for electromagnetic disturbances of the types which can be expected in public medium voltage power supply systems, for guidance in: a) the limits to be set for disturbance emission into public power supply systems (including the planning levels defined in 3.1.5); b) the immunity limits to be set by product committees and others for the equipment exposed to the conducted disturbances present in public power supply systems. The disturbance phenomena considered are: voltage fluctuations and flicker, harmonics up to and including order 50, inter-harmonics up to the 50th harmonic, voltage distortions at higher frequencies (above 50th harmonic), voltage dips and short supply interruptions, voltage unbalance, transient overvoltages, power frequency variation, d.c. components, mains signalling. The medium-voltage systems covered by this standard are public distribution systems supplying either: a) private installations in which equipment is connected directly or through transformers, or b) substations feeding public low-voltage distribution systems.

IEC TR 61000-2-8:2002, which is a technical report, describes the electromagnetic disturbance phenomena of voltage dips and short interruptions in terms of their sources, effects, remedial measures, methods of measurement, and measurement results (in so far as these are available). They are discussed primarily as phenomena observed on the networks of public electricity supply systems and having an effect on electrical equipment receiving its energy supply from those systems.

IEC 61000-2-4:2002 is concerned with conducted disturbances in the frequency range from 0 kHz to 9 kHz. It gives numerical compatibility levels for industrial and non-public power distribution systems at nominal voltages up to 35 kV and a nominal frequency of 50 Hz or 60 Hz. Compatibility levels are specified for electromagnetic disturbances of the types which can be expected at any in-plant point of coupling within industrial plants or other non-public networks, for guidance in
a) limits to be set for disturbance emission into industrial power supply systems;
b) the choice of immunity levels for the equipment within these systems.
The contents of the corrigendum of July 2014 have been included in this copy.

This standard is concerned with conducted disturbances in the frequency range from 0 kHz to 9 kHz, with an extension up to 148,5 kHz specifically for mains signalling systems. It gives compatibility levels for public low voltage a.c. distribution systems having a nominal voltage up to 420 V, single-phase or 690 V, three-phase and a nominal frequency of 50 Hz or 60 Hz. Compatibility levels are specified for electromagnetic disturbances of the types which can be expected in public low voltage power supply systems, for guidance in: - the limits to be set for disturbance emission into public power supply systems; - the immunity limits to be set by product committees and others for the equipment exposed to the conducted disturbances present in public power supply systems.

Interest in magnetic fields has been stimulated in recent years by concern over the physiological effects they may have on humans and animals and the deleterious effects they have on the performance of some electrical equipment, particularly video display units. Investigations have yielded results which are presented in this report as reference values.

Applies to electrical equipment using signals in the frequency range from 3 kHz up to 525 kHz to transmit information on low-voltage electrical installations, either on the public supply system or within customers' premises. Specifies frequency bands allocated to different applications (where appropriate), limits for the terminal output voltage in the operating band and limits for conducted and radiated disturbance. It also gives the methods of measurement. Specifies disturbance limits in the frequency range from 3 kHz up to 400 GHz.

This technical report outlines principles which are intended to be used as the basis for determining the requirements for connecting large fluctuating loads (producing flicker) to public power systems. The primary objective is to provide guidance for engineering practices which will ensure adequate quality for all connected consumers. This report primarily focuses on controlling or limiting flicker, but a clause is included to address voltage magnitude changes and their effects.

This technical report outlines principles which are intended to be used as the basis for determining the requirements for connecting large distorting loads (producing harmonics and/or interharmonics) to public power systems. The primary objective is to provide guidance for engineering practices which will ensure adequate service quality for all connected consumers. Since the guidelines outlined in this report are necessarily based on certain simplifying assumptions, there is no guarantee that this approach will always provide the optimum solution for all harmonic problems. The recommended approach should be used with flexibility and judgment as far as engineering is concerned, when applying the given assessment procedures in full or in part.