B4-66 Implications for harmonics and filtering of staggered installation of HVDC converter stations in proximate locations

Several ongoing and proposed HVDC projects consist of two near-identical transmission connections, between identical or proximate AC connection points, but staggered in installation date, perhaps by several years. This delayed installation of the second transmission is typically done in order to match transmission capacity to the build-up of generation capability or load growth.

Many technical aspects of the close location of converter stations have already been covered in the work of WG B4.41 and the resulting Technical Brochure 364 on “Systems with Multiple DC Infeed”. However, intentional and planned staggered installation of stations with identical or near identical HVDC schemes being connected in close proximity to each other poses some different issues, particularly in the area of harmonics and filtering. Such issues include:

• Specification of harmonic limits at the time of the first installation which will also permit the connection of the anticipated second station without breaching regulatory limits.

• The validity of the recommendations in IEC 61000-3-6, Chapter 9 need to be examined.

• The transfer of harmonics between LV-MV-HV and EHV may need to be considered.

• Consideration of harmonic limits for joint operation, which may be different from the limits applicable to each station individually.

• Compatibility of filter designs to achieve fair sharing of harmonic load between stations

• Prevention of overloading of one station’s filters by the other

• Possible inter-changeability of filters from either station to enhance operational flexibility and increase redundancy.

Terms of Reference (pdf, 52kB)

 WG Members:

Cattan JusanFernandoBR
Sankar SoundrapanianUS
Ho ChungYongKR
Pires de CarliMiguelBR
MaggThomas GeorgZA
Willcox de SouzaLuiz FelipeBR
Correia LimaManfredoBR