EN 62747:2014/prA2:2025

Terminology for voltage-sourced converters (VSC) for high-voltage direct current (HVDC) systems

Terminologie für Spannungszwischenkreis-Stromrichter (VSC) für Hochspannungsgleichstrom(HGÜ)-Systeme

Terminologie relative aux convertisseurs de source de tension (VSC) des systèmes en courant continu à haute tension (CCHT)

Terminologija za napetostne pretvornike (VSC) za visokonapetostne enosmerne sisteme - Dopolnilo A2

General Information

• Status: Not Published
• Publication Date: 31-Aug-2026
• ICS: 29.200 - Rectifiers. Convertors. Stabilized power supply
• ICS: 29.240.99 - Other equipment related to power transmission and distribution networks
• Technical Committee: CLC/TC 22X - Power electronics
• Current Stage: 4060 - Enquiry results established and sent to TC, SR, BTTF - Enquiry
• Start Date: 02-May-2025
• Completion Date: 02-May-2025
• Ref Project: SIST EN 62747:2014/oprA2:2025 - Amendment 2 - Terminology for voltage-sourced converters (VSC) for high-voltage direct current (HVDC) systems

Relations

• Amends: EN 62747:2014 - Terminology for voltage-sourced converters (VSC) for high-voltage direct current (HVDC) systems
• Effective Date: 12-Mar-2024

Overview

EN 62747:2014/prA2:2025 (Amendment 2 to IEC 62747) is a terminology-focused standard for voltage‑sourced converters (VSC) used in high‑voltage direct current (HVDC) systems. Published as a CLC adoption of IEC CDV 62747 AMD2, the document updates and clarifies vocabulary, graphical symbols and device-level definitions used in VSC‑based HVDC technology. As a Committee Draft for Vote (CDV) the text is under review and may be subject to change; the proposed stability date is 2026.

Key Topics

• Terminology for VSC and HVDC: Standardizes terms used across HVDC VSC literature and engineering practice to improve clarity and interoperability.
• Graphical symbols: Replaces previous figure with Table 1 listing symbols for common power‑electronic elements (e.g., IGBT‑diode pair, switch‑type valves, controllable voltage‑source valves, bridges, dynamic braking valves).
• Converter units and valves: Updates figures and descriptions for VSC converter unit layouts and valve representations (including dynamic braking and protective devices).
• Submodule definition: Revises the MMC (modular multilevel converter) submodule definition from a single IGBT‑diode pair to “one serial element of one or more parallel‑connected IGBT(s) and diode(s)”.
• Topologies: Adds formal definitions for half‑bridge topology and full‑bridge topology at MMC building‑block level, describing operating switch positions and module voltage states.

Practical Applications

This amendment is practical for organizations and professionals who need consistent, authoritative vocabulary and symbols when designing, documenting, procuring or testing VSC‑HVDC equipment:

• Power‑electronics and HVDC system designers - use standardized terms and symbols in schematics, datasheets and engineering drawings.
• Manufacturers and integrators - ensure consistent interpretation of MMC submodule options (half‑bridge vs full‑bridge) and valve types during specification and production.
• Test labs and certification bodies - reference uniform terminology during conformance testing and reporting.
• Project owners and procurement teams - reduce ambiguity in tender documents, technical specifications, and interoperability requirements.
• Training and documentation - produce clear educational materials and manuals for VSC HVDC technologies.

Related Standards

• IEC 62747 (base document) and prior editions/amendments (this is Amendment 2).
• References to ISO/IEC Directives for standard development and harmonization.

Note: This CDV is intended for parallel IEC‑CENELEC review and contains editorial and definitional updates. Users should consult the final published edition for normative application.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2025
Terminologija za napetostne pretvornike (VSC) za visokonapetostne enosmerne
sisteme - Dopolnilo A2
Amendment 2 - Terminology for voltage-sourced converters (VSC) for high-voltage direct
current (HVDC) systems
Terminologie für Spannungszwischenkreis-Stromrichter (VSC) für
Hochspannungsgleichstrom(HGÜ)-Systeme
Terminologie relative aux convertisseurs de source de tension (VSC) des systèmes en
courant continu à haute tension (CCHT)
Ta slovenski standard je istoveten z: EN 62747:2014/prA2:2025
ICS:
01.040.29 Elektrotehnika (Slovarji) Electrical engineering
(Vocabularies)
29.200 Usmerniki. Pretvorniki. Rectifiers. Convertors.
Stabilizirano električno Stabilized power supply
napajanje
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

22F/809/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62747/AMD2 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2025-02-07 2025-05-02
SUPERSEDES DOCUMENTS:
22F/768/CD, 22F/796A/CC
IEC SC 22F : POWER ELECTRONICS FOR ELECTRICAL TRANSMISSION AND DISTRIBUTION SYSTEMS
SECRETARIAT: SECRETARY:
IEC Secretariat Ms Suzanne Yap
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
TC 115
ASPECTS CONCERNED:
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of
which they are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is
the final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Amendment 2 - Terminology for voltage-sourced converters (VSC) for high-voltage direct
current (HVDC) systems
PROPOSED STABILITY DATE: 2026
NOTE FROM TC/SC OFFICERS:
This CDV is prepared based on 22F/768/CD and the agreed NC comments in 22F/7796A/CC by SC
22F/MT 33 (Convenor: Mr. Marcus Haeusler).

download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National
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IEC CDV 62747 AMD2 © IEC 2024 – 2 – 22F/809/CDV
1 INTERNATIONAL ELECTROTECHNICAL COMMISSION
2 ____________
4 TERMINOLOGY FOR VOLTAGE-SOURCED CONVERTERS (VSC)
5 FOR HIGH-VOLTAGE DIRECT CURRENT (HVDC) SYSTEMS
7 AMENDMENT 2
9 FOREWORD
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