National foreword

This Published Document is the UK implementation of IEC SRD 63317:2025.

The UK participation in its preparation was entrusted to Technical Committee GEL/50, Low Voltage Direct Current for Electricity Access.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

This publication is not to be regarded as a British Standard.

Compliance with a Published Document cannot confer immunity from legal obligations.

This Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 November 2025.

FOREWORD

The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees.
IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user.
In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies.
All users should ensure that they have the latest edition of this publication.
No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication.
IEC draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC shall not be held responsible for identifying any or all such patent rights.

IEC SRD 63317 has been prepared by IEC systems committee LVDC: Low Voltage Direct Current and Low Voltage Direct Current for Electricity Access. It is a Systems Reference Deliverable.

The text of this Systems Reference Deliverable is based on the following documents:

Full information on the voting for its approval can be found in the report on voting indicated in the above table.

The language used for the development of this Systems Reference Deliverable is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are described in greater detail at www.iec.ch/publications.

The committee has decided that the contents of this document will remain unchanged until the stability date indicated on the IEC website under webstore.iec.ch in the data related to the specific document. At this date, the document will be

reconfirmed,
withdrawn, or
revised.

INTRODUCTION

The electrical distribution in industrial applications has a high number of motor drives and machinery with high peak power demand. More and more production sites integrate photovoltaic (PV) systems and battery storage systems. They reduce the peaks of infeed power which drive the price of electrical energy up. Furthermore, energy storage can be used to increase the availability of electrical energy supply and thus the security of supply within the system. Moving to DC distribution can help to overcome those challenges and is expected to provide new opportunities to increase efficiency. This can be achieved in low-voltage DC (LVDC) because there are lower conversion losses and a cost-effective bidirectional integration of motor drives and batteries is possible. LVDC is already used in many applications in industry, but not all parts are compatible with a LVDC system since they do not have standardized interfaces.

This document harmonizes the system aspects of LVDC distribution systems in the application of industrial production. This document will enable factories to implement an open, vendor-independent industrial LVDC system with renewable sources, electrical energy storage systems, bidirectional motor drives and other applications. It also defines necessary boundaries and interfaces for connected devices or subsystems. As a Systems Reference Deliverable, it is intended to harmonize between the different product standards of all involved technical committees.

LVDC supports the following Sustainable Development Goals of the United Nations [1]1:

Goal 7: "Ensure access to affordable, reliable, sustainable and modern energy for all"
DC grids enable industry to easily integrate solar energy and renewable energy into their production lines and makes the system more and more affordable. The DC nature of electrical energy storage systems such as batteries and capacitors simplifies the integration and increases the reliability of the factory grids.
Goal 8: "Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all"
Goal 9: "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation"
Storage devices like batteries or capacitors help to bridge power outages. This makes production more robust and reduces waste from defective parts because of power failure.
Goal 11: "Make cities and human settlements inclusive, safe, resilient and sustainable"
Goal 12: "Ensure sustainable consumption and production patterns"
DC systems need fewer resources; less copper, housing materials, electronic equipment, etc. Battery storage also reduces the in-feed power of the production line. This leads to lower investment for transformers and energy distribution within the factory, as well as reduced peak-power electricity rates. In AC the braking energy is dissipated in braking resistors while DC enables the reuse of otherwise wasted energy by other devices.
Goal 17: "Partnership for the Goals".

This document follows the IEC systems approach from the domain to the gap analysis and gives guidance by describing reference implementation.

1 Scope

This document describes certain aspects of standardization of LVDC industrial applications.

These industrial applications apply to the secondary economic sector where the processing of resources applies to the production, distribution and storage of physical goods, typically in a factory or similar areas.

The local LVDC distribution can be connected to the public grid (AC or DC) or can work completely off-grid (intentional islanding).

This document provides a practical guideline for the design and planning of industrial LVDC systems, aiming at interoperability amongst different devices.

IEC use case descriptions of the described industry application are part of this document.

NOTE This document is not intended for following applications: railway, ships, vehicles, aircraft, public distribution. But wherever possible and practicable, compatibility of product requirements is considered favourable.

Included is equipment which is especially designed for and intended for use in industrial areas. This includes everything that is concerned with with the commercial extraction, processing and further processing of raw materials or intermediate products into material goods; in particular, machines, plants, storage facilities and transport systems.

Not included is equipment which is especially designed for and intended for use in ordinary buildings:

supporting building equipment (e.g. lighting and HVAC) in buildings or parts of buildings in which machines, plants, storage equipment and transport systems are installed;
building equipment in buildings or parts of buildings in which supporting and administrative production functions are performed (e.g. offices).

2 Normative references

3 Terms and definitions

4 State of the art

4.1 Today's structures for power supply

4.2 Auxiliary energy

5 Domain description and analysis

5.1 General

5.2 Typical drivers

6 Description of system architectures

6.1 System architectures (Stage 2 - System Architecting)

6.2 Technical challenges to overcome

7 Use cases (Stage 3 - Use Case Analysis)

7.1 General

7.2 Use case description of braking energy recuperation

8 Aspects of DC systems for industrial usage (Stage 4 - System Modelling)

8.1 Preconditions necessary to connect to a DC system

8.2 Risks specific to direct current

8.3 Topologies for DC grids

8.4 Network and earthing configuration

8.5 Electromagnetic compatibility (EMC)

8.6 Grid behaviour

8.7 System stability

8.8 Protection for safety

9 Standard analysis (Stage 5 - Standards Analysis)

9.1 Survey of existing standards

10 Gap analysis (Stage 6 - Gap Analysis)

10.1 Survey of additional standardization needs

10.2 Mapping of aspects to standardization needs

Bibliography

PD IEC SRD 63317:2025

Low-voltage direct current (LVDC) industry applications

Current

Published:

30 Nov 2025