Safe EV charging

Electric vehicles charging systems rely on IEC International Standards

By Morand Fachot

As electric vehicles (EVs) become more popular in many parts of the world, ensuring that charging systems for these operate safely and reliably is central to wider EV adoption. This rests to a significant extent on IEC International Standards for EV conductive charging systems.  A new edition of the general requirements for these has just been published. It is a complete overhaul and much expanded version of the previous edition.

eNterop charging for EVs EV charging systems rely on many IEC TC 69 Standards as well as on ISO/IEC 15118 vehicle-to-grid (V2G) communication interface (Siemens AG press photo)

Starting with the basic…

The majority of electric road vehicles, full electric or hybrids, rely on batteries for energy, with the exception of fleets of larger vehicles such as urban transport buses or industrial truck that can use fuel cells certain. The number of these so-called battery-powered EVs (BEVs) is expected to overtake conventional vehicle powered by internal combustion engines (ICEs) in coming decades.  

Charging batteries for BEVs can be done through well-established conductive systems using charging outlets connecting to the vehicles via special cables, sockets and plugs, or through wireless power transfer (WPT), which is a more recent charging system.

To ensure conductive charging systems are safe and reliable IEC TC 69: Electric road vehicles and electric industrial trucks, which was created in 1969, develops the IEC 61851 series of International Standards for these.

As of April 2017 IEC TC 69 had published five International Standards in this series and is developing nearly 20 more 

Third edition of fundamental Standard is a comprehensive overhaul

IEC TC 69 has just published the third edition of IEC 61851-1:2017, Electric vehicle conductive charging system – Part 1: General requirements. This edition is greatly expanded on the previous one, published in 2010.

This Standard applies to EV supply equipment for charging electric road vehicles, with a rated supply voltage up to 1 000 V AC or up to 1 500 V DC and a rated output voltage up to 1 000 V AC or up to 1 500 V DC. It covers the following aspects:

  • characteristics and operating conditions of the EV supply equipment
  • specification of the connection between the EV supply equipment and the EV
  • requirements for electrical safety for the EV supply equipment

The content of this edition has been re-ordered, the numbering of clauses has changed as new clauses have been introduced and some contents moved for easy reading.

All requirements from IEC 61851-22, which covered AC charging station aspects, have been moved to this Standard, as work on IEC 61851-22 has ceased.

Any requirements that concern electromagnetic compatibility (EMC) have been removed from the text and are expected to be part of the future version of IEC 61851-21-2, Electric vehicle on-board charger EMC requirements for conductive connection to AC/DC supply.

The content of previously existing annexes has been significantly expanded and two new informative annexes have been added.

This third edition of the Standard also contains significantly more figures, 42 against 25 in the previous edition.

Full details of the extensive technical changes contained in this Standard compared to the previous edition are available from the relevant page on the IEC webstore.

This third edition of IEC 61851-1 will ensure that general requirements for EV conductive charging systems will be comprehensively covered and help support the growing adoption of BEVs.

Gallery
eNterop charging for EVs EV charging systems rely on many IEC TC 69 Standards as well as on ISO/IEC 15118 vehicle-to-grid (V2G) communication interface (Siemens AG press photo)
Nissan Leaf charging cables Nissan Leaf EV cables and adapters collection
EV fast-charging system Efacec fast-charging systems for EVs are installed on stretches of German motorways (Photo: Efacec)