Standards Development

Scope

From this edition, the CLC TS 50654-2 is the adoption (identical) of the IEC TS 63291-2 (not covered by a parallel procedure). This document defines aspects on planning, specification, and execution of multi-vendor HVDC grid systems also referred to as HVDC grids.

The terms "HVDC grid systems" or "HVDC grids" are used in this document to describe HVDC systems for power transmission having more than two HVDC stations connected to a common DC circuit. The DC circuit can be of radial or meshed topology or a combination thereof.

In this document, the term "HVDC grids" is used. While this document focuses on requirements specific for HVDC grids, some requirements are considered applicable to all HVDC systems in general, i.e., including point-to-point HVDC systems. Existing IEC (e.g., IEC TR 63363-1 [1]), Cigre or other relevant documents have been used for reference as far as possible.

Corresponding to electric power transmission applications, this document is applicable to high voltage systems, i.e., those having typically nominal DC voltages higher than 50 kV with respect to earth are considered in this document.

NOTE While the physical principles of DC networks are basically voltage independent, the technical options for designing equipment get much wider with lower DC voltage levels, e.g. in the case of converters or switchgear.

This document covers technical aspects of:

• coordination of HVDC grid and AC systems,

• HVDC grid characteristics,

• HVDC grid control,

• HVDC grid protection,

• AC/DC converter stations,

• HVDC grid installations, including DC switching stations and HVDC transmission lines,

• studies and associated models,

• testing.

Beyond the scope of this document, the following content is proposed for future work:

• DC/DC converter stations.

Purpose

During the TC8X 2023 plenary meeting (TC8X/0202/RM), after the WG06 report, that contained the proposal for the CLC TS 50654 series next edition, the following decision was taken: DECISION 8X 2023/10: TC8X approves WG6 proposal launch a NWI in view of adopting IEC/TS 63291-1 and IEC/TS 63291-2. TC8X entrusts the TC8X Officers with the drafting of the NWI form. CLC TS 50654-1 and CLC TS 50654-2 will be withdrawn after the publication of CLC TS 63291-1 and CLC TS 63291-2. By considering the similarity already present inside titles, scopes, perimeters, series composition etc. between actual CLC TS 50654series and IEC TS 63291 series, the best way is to perform identical adoption as new edition of the CLC TS 50654-1 and CLC TS 50654-2