4.
Figure 4-5 Hybrid AC-DC grid with voltage source converter (VSC) interlink
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MVDC technologies and operational considerations
SSTs come several topologies, broadly
categorized single isolation, modular isolation,
and multiport isolation. Each design involves trade-
offs cost, efficiency, complexity and harmonics
or electromagnetic emissions [42]. The dynamic
nature the grid, where impedance profiles
continuously evolve different assets are
integrated disconnected, can exacerbate these
harmonic disturbances, potentially triggering
resonance and compromising system stability and
safety [43]. SSTs are increasingly seen essential
for future MVDC power systems, especially for
integrating renewable energy, powering data
centre, and supporting high-power charging.4, likely that the future
power system will consist mix grids and
DC grids, with power electronic converters serving
as the interface between them. example of
such system shown Figure 4-5.5 Harmonic filtering
As described section 2. One option for addressing
these harmonic challenges the modular multilevel
converter.
A key challenge hybrid AC-DC systems the
impact the interlink power electronic converter,
whose switching behaviour introduces harmonic
currents into the network. While extensive research has focused
on mitigating AC-side harmonics, comparatively
less attention has been given control strategies
specifically designed for suppressing DC-side
current harmonics.2. Many SSTs
can operate AC-AC, AC-DC, DC-AC DC-DC
converters
