1.1 General
These Guidelines and Parameter Lists to Functional Specifications describe specific
functional requirements for HVDC Grid Systems. The terminology “HVDC Grid Systems” is used here describing HVDC systems for power transmission having more than two
converter stations connected to a common d.c. circuit.
While this document focuses on requirements, that are specific for HVDC Grid Systems, some requirements are considered applicable to all HVDC systems in general, i.e.
including point-to-point HVDC systems. Existing IEC, Cigré or other documents relevant
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. only nominal d.c. voltages equal or higher than 50 kV
with respect to earth are considered in this document.
NOTE While the physical principles of d.c. networks are basically voltage independent,
the technical options for designing equipment get much wider with lower d.c. voltage
levels, e.g. in case of converters or switchgear.
Both parts have the same outline and headlines to aid the reader.