Position #30 – Solid State Transformers for DC connection in HVDC network for Wind Power

Host institution
ES - Universidad Politecnica de Madrid
Lab or research department name
Centre of Industrial Electronics (CEI)
Electrical Engineering
Sub-domain or keywords
HCDC network, switched converters, circuit breakers, power flow in DC connection
Type of mobility
Duration (months)
From 12 to 15

Renewable energy sources are often located far away from consumption centers (e.g. offshore wind farms). For this reason, power delivery through long distances is getting increasingly important. From the beginning of 20th century and up to nowadays, electric power has been predominantly transmitted and distributed in AC due to the unavailability of well-suited DC/DC converters. However, the emergence of a wider range of power electronics devices is contributing to revitalize the research on DC transmission networks. DC grids present several advantages in comparison with AC grids: in DC networks there are not reactive power, so their transmission capacities are increased, they also produce fewer losses than AC grids, the weight and cost of components is lower (fewer cables), and the efficiency is higher. It is in this context where DC/DC converters play a decisive role. Since energy is generated at low voltages and highly efficient devices are needed to increase these voltages to higher values. Furthermore, these converters have to be bidirectional. This research proposal is focused on topologies and control of DC/DC bidirectional converters valid for the integration of offshore wind farms in a High Voltage Direct Current (HVDC). Advanced topologies solutions will be analysed and compared: Multilevel topologies, series/parallel connection of Dual Active Bridge. The use of Wide Band Gap semiconductors will be considered for these HV applications and compared with the corresponding Si devices. Advanced control techniques for the different proposed solutions will be considered as well as the particular performance required for this bidirectional DC/DC solid state transformers.

From January 2016
Maximum available positions
Fluent English. Experience in Power Electronics would be preferable.
Pedro Alou <pedro.alou@upm.es>