Suggestions for broad areas requiring new
standardization work are set out below.2.
7.
MVDC demands selective, multilevel, local fault
isolation keep the rest the grid running
§ Grounding and earthing: HVDC typically
applies solid direct grounding.1 System and operation
With MVDC such recent technology grid
operations, broad range topics needs
examination:
§ Grid engineering procedures
§ Design procedures
§ System functional requirements and testing
§ Operating performance evaluation
§ Black start and reconnection procedures and
testing
§ Data exchange models
7.2.1.2.2.3 Security
§ MVDC converter station cybersecurity
7.2. Specifically, the following
areas need work:
§ System architecture and planning: HVDC
typically assumes point-to-point simple
multi-terminal structures. MVDC requires
guidance for diverse topologies (radial, ring,
mesh, hybrid, intensively branched) that are
more complex than those typically considered
in HVDC
§ Protection coordination and fault management:
HVDC uses uniform-level, zone-based tripping.4 Converters
§ Converter station control and protection
requirements
§ Power converter operation standards and
maintenance procedures
§ Grid converter design and system support
functions
§ Converter test methods
§ High-capacity MVDC charger design and
protection
§ Power converter electromagnetic compatibility
issues
§ Power converter common information model
(CIM)
.63
Standardization for MVDC grids
7.1.1.2 Required new standards
While many existing standards can extended
to encompass MVDC grid operations and
technologies, some areas they not have
sufficient breadth account for the unique
characteristics MVDC.
MVDC must integrate with feeders, DERs,
and microgrids bidirectionally
Given the many outstanding issues, range of
new standards will required facilitate the
widespread uptake MVDC technology power
grids.1 Terms and general requirements
Standards are required define MVDC terminology
and general system requirements.2 Grounding and protection
§ Fault current coupling and protection with
MVDC operation
§ MVDC grid grounding design and protection
coordination
§ Ground fault monitoring
§ Protection relay design, operation and testing
7. MVDC
requires variety grounding schemes, tailored
to safety, network topology and application
§ Multi-terminal operations: HVDC does not
support the frequent reconfiguration or
dynamic load-serving that expected of
MVDC systems
§ Interaction with AC: HVDC not designed for
frequent, decentralized interaction with AC.
7.1
