Standards Development

Scope

This part of IEC 62271 specifies the service conditions, rated characteristics, general structural requirements and test methods of compact switchgear assemblies, mobile substations and prefabricated substations. These compact switchgear assemblies, mobile substations and prefabricated substations are for indoor and/or outdoor installations in systems having rated voltages at the high voltage side above 52 kV and service frequencies of 50 Hz and 60 Hz.

–        In general, compact switchgear assemblies consisting of at least one switching device (circuit-breakers, disconnectors/earthing switches, switches, disconnecting circuit-breakers, etc.)  directly connected to one or more other devices (instrument transformers, surge arresters, bushings, cable connections, transformer connections, etc.) such that there is an interaction between the functions of the individual devices. The devices, defined by IEC standards, which may form part of a compact switchgear assembly are listed below:

Switching devices:

–        Circuit-breakers                                  IEC 62271-100

–        Disconnectors/earthing switches        IEC 62271-102

–        Switches                                             IEC 62271-104

–        Disconnecting circuit-breakers           IEC 62271-108Devices:

–        Instrument transformers

–        Current transformers                          IEC 61869-1, IEC 61869-2

–        Voltage transformers                          IEC 61869-1, IEC 61869-3, IEC 61869-5

 –        Combined transformers                     IEC 61869-4

Surge arresters                                             IEC 60099-4

Bushings                                                       IEC 60137

Insulators                                                      IEC 61462, IEC 62155

Cable connections                                        IEC 62271-209

Transformer connections                              IEC 62271-211

The assemblies may contain components of air insulated switchgear (AIS) only or a combination of part of AIS and part of gas insulated switchgear (GIS), so called mixed technology switchgear (MTS) and may be delivered entirely prefabricated or partially assembled.

It is not possible to define all potential arrangements of compact switchgear assemblies however four examples are shown for information in Annex A.

This standard covers the influence on performance of the interactions between devices within compact switchgear assemblies and defines ratings and test procedures for these assemblies.

This document is applicable for GIS which are covered by 62271-203:2022 if the design is applicable for mobile substation or prefabricated substation.

This document does not apply to compact switchgear assemblies consisting solely of GIS which are covered by 62271-203:2022.

–        In general, it is not possible to define all potential arrangements of substations, mobile substations and prefabricated substations include at least the following modules (The typical wiring diagrams are for information in Annex B):

High-voltage module;

Transformer module;

Medium-voltage module;

Protection and control module;

Vehicle-mounted system (only for mobile substations).

IEC 62271-1:2021 is applicable if not stated otherwise.

Note: For the use of this document high-voltage (IEC 60050-601:1985[3], 601-01-27) is the rated voltage above 1 000 V. However, medium voltage (IEC 60050-601:1985, 601-01-28) is commonly used for distribution systems with voltages above 1 kV and generally applied up to and including 52 kV;