Modular power electronic devices for LVDC grids
Pavel Purgat, TU Delft
For power electronics to enable a genuinely robust, scalable and flexible low voltage dc distribution grid, adequate and efficient power converter topologies must be developed. Therefore, in the DCSmart project, we have proposed a power flow control converter, that process only a fraction of the power flowing through the line. (a fractional power rating), offering a cost-effective and efficient method for controlling the power flow of the network. The converter also integrates the short circuit protection device that can interrupt the fault current. The partial power rating is achieved via a series-parallel connection of the converter to the grid. The power flow is controlled via the injection of a small voltage in series with a power line.
Universal DC Distribution Grids: Modelling, Stability and Control
Nils van der Blij, TU Delft
To advance the broad adoption of DC distribution grids a universal system architecture is proposed consisting of nano-, micro- and macrogrids. Furthermore, modelling techniques are developed for steady-state and dynamic analysis. These modelling tools are used to develop stability analysis techniques and guidelines for plug-and-play distribution grids. Finally, methods to manage congestion in distribution grids are developed using the allocation of storage and control of electric vehicle charging.
Bipolar regional and local DC grids – balancing converter, power management and safety requirements
Matthias Shultz, Fraunhofer
In the past, one DC/DC converter was necessary to handle the bidirectional power flow between a local (±380 V) and a regional (±760 V) bipolar DC grid. A second DC/DC converter in series balancing the power between plus and minus phase of the regional grid. Fraunhofer IISB developed in the project DCSmart a non-isolated bidirectional topology, which works as a bidirectional converter with integrated balancing capability. Furthermore, Fraunhofer IISB dealt with safety and power requirements for DC grids and developed bidirectional electronic safety elements to limit and clear overcurrent and short-circuit failure inside a bipolar DC grid.
The spatial dimension of energy consumption
Bardia Mashhoodi, TU Delft
Studies are conducted on two separate, yet interconnected, issues: (a) household energy consumption (HEC), and (b) allocation of charger points for electric vehicles. The results show that in AMA (Amsterdam metropolitan area): (i) impact of socioeconomic factors on HEC is significant; (ii) energy poverty is boosted in the private rental housing sector; (iii) urban heat island are affecting HEC; (iv) spatial distribution of EV charger can effectively reduce the costs.
Electricity Markets for DC distribution systems
Longjian Piao, TU Delft
Unbundling of the power sector requires the operation of DC distribution systems (DCDS) to be market-driven. However, their unique technical features, including low system inertia and strict power limits, cannot be handled by the conventional AC market designs. Hence, we aim to design local electricity markets that provide both energy and DC system services, following a general framework of identifying goals, listing options, making choices, and testing performance. Agent-based simulations indicate that the inclusion of flexibility markets incentivizes prosumers to regulate DC nodal voltage, thereby creating new business models for batteries and EVs in a DCDS.
