The project
features three voltage levels: ±10 kV, ±375 V,
and Two AC/DC converters convert
power from ±10 DC. demonstration test also
scheduled 2027, applying ±20 MVDC
to existing 22. Known
officially “Development AC/DC Hybrid
Distribution Network Technology”, the goal of
these efforts develop MVDC technologies
and operate them hybrid manner with the
existing MVAC distribution systems. This work
involves wide range participants, including
KEPCO, the government-funded Korea
Electrotechnology Research Institute (KERI),
major power equipment companies such as
Hyosung Heavy Industries, Electric, and
HD Hyundai Electric, well academic
institutions such Seoul National University
and Hanyang University.9 MVAC distribution lines
to evaluate integration renewable energy
sources.
Korea also hosts number MVDC technology
development projects, including:
§ Development MW-class modular
converter station and multi-terminal-based
converter station enable interconnection
between MVDC and LVDC.
§ KEPCO currently finalizing development of
an AC/DC hybrid distribution system and plans
to begin testing the Go-Chang test site by
the end 2025. The technology
is being developed ensure scalability
in both voltage and capacity, allowing the
entire system configured using identical
modules.
The ±10 network adopts dual-terminal
ring structure. A
summary contemporary South Korean work
on MVDC technology applications shown in
Figure 6-4.7 China
One standout MVDC project China the Suzhou
Wujiang project [64], located Suzhou, the
eastern Jiangsu Province.
§ ±20 kV, MMC-based converter
station being developed, together with
measurement, monitoring, and diagnostic
technologies for key equipment, which will be
applied this testbed project.
Other work includes studying the techniques
necessary for the design and analysis hybrid
AC and MVDC distribution networks, including
network reconfiguration, voltage control, power
flow calculation, and protection coordination. In
progress also development high-density
voltage and frequency transformers, well
as gateway and cybersecurity technologies for
upper-level communication the converter
station. This
infrastructure can utilized for key MVDC
testing adjusting the test voltage.
Another key Chinese project the Zhuhai MVDC
project, described the case study below. consists flexible
DC converter station, distributed PV, energy
storage, charging stations, and industrial,
commercial, and residential loads.56
MVDC projects around the world
distribution networks and has invested
USD 141M MVDC-related work. System verification scheduled to
begin the second half 2025.
6.
§ KERI Changwon building internationally
accredited testing system through the Ministry
of Trade, Industry and Energy’s project
“Establishment International Testing and
Certification Infrastructure for Ultra-High
Voltage DC-based Power Equipment”. One the
converters uses half-bridge sub-modules (HBSM)
topology, while the other one utilizes hybrid
modular multilevel converter (HMMC) topology.
. Issues such
as control and protection coordination of
converter stations also being explored
