Modular Multilevel (MMC) type Voltage
Source Converters (VSC) together with DC cable systems have been the preferred
choice of HVDC transmission technology. Ever evolving converter topologies have
imposed challenges on the performance of HVDC cable systems. Differences in converter
control in case of faults, both AC and DC can affect the travelling wave
phenomena in the cable system.
investigate different types of faults in 320 kV symmetrical monopolar cable-based
MMC type VSC HVDC converter system with a focus on investigating the impacts of
converter control systems on voltage and current profiles (peak value and time characteristics)
during the faults on a AC and DC side.
of the art HVDC converter control system
knowledge on international standards and recommendations, such as IEC, CIGRÉ
PSCAD model of symmetrical monopolar cable-based multi-level VSC used in a typical
offshore wind farm point-to-point interconnector with detail models of cable
and converter control systems.
the impact of converter internal & external AC faults and DC cable faults
on the transient stresses on the HVDC cable.
control parameters/schemes with a potential to affect overvoltage profiles and
carry out systematic study of the parameters effects on such overvoltages.
recommendation based on the study
student will be provided with an opportunity to visit the HVDC cables factory
of NKT in Karlskrona, Sweden. This enable the student to receive valuable
feedback from the cable experts on the cable system development, testing and
and duration of thesis:
30-35 ECTS (5-6 months)
thesis is a collaboration between DTU ELEKTRO and DTU WIND
Nenad Mijatovic - DTU ELEKTRO
Nicolaos A. Cutululis- DTU WIND
Naidu Sakamuri - DTU WIND
Karmokar - NKT Sweden
I samarbejde medNKT cables group A/S