Giel Van den Broeck

MatLVDC: A new open source Matlab toolbox to simulate DC networks including power electronic converters and distributed energy resources

This paper presents MatLVDC, i.e. an open source Matlab toolbox to analyse dynamic phenomena in DC distribution networks, that are gaining importance because of reported energy savings and the increasing number of DC loads and distributed energy resources (DER). The toolbox aims at facilitating the design processes and research on DC distribution networks including a high share of renewable energy sources (RES). It is capable of running large-signal time-domain simulations, analysing parameter sensitivity and small-signal linearization. Therefore the toolbox composes a non-linear state-space description that includes models of the generation and load subsystems, power electronic converters and network equations. Via a user-friendly input data format, the user can quickly run a simulation and study the influence of design decisions, different network topologies and controller parameters on the bus voltages and line currents. This paper describes the toolbox features and provides two simulation examples to demonstrate the usability of the toolbox.

Analysis of three-level converters with voltage balancing capability in bipolar DC distribution networks

The growing number of distributed energy resources, DC loads and energy storage systems drive the adoption of DC distribution networks. This paper in particular addresses three-wire bipolar DC distribution networks (b-DCDN), that provide two voltage levels to connect low- and high-power loads, while transferring twice the amount of power with less conduction losses as compared to the two-wire unipolar network configuration. To stabilize and control these two voltage levels, converters with voltage balancing capability are essential. Although dedicated voltage balancing converters that transfer power between both poles exist, this paper shows the extent to which certain three-level DC-DC converters can both interface DC devices such as battery energy storage systems and balance the pole-to-neutral voltages in the presence of unbalanced currents. More in particular, this paper identifies and analyzes the members of the non-isolated three-level converter family that feature a bipolar DC front-end in different unbalanced conditions, thereby explicitly deriving the operating area of these converters, based upon a decomposition in balanced and unbalanced components. Furthermore, the paper demonstrates the influence of the modulation scheme in unbalanced conditions on the current ripple and required inductance.

Power electronics for potential distribution dc power evolution: A review

Power systems of the future are believed to be shaped by the introduction of smart grids and microgrids where distributed generation is dominant at the distribution level. DC distribution is also a potential microgrid solution. Distributed generation and loads interconnect to DC-common feeders via power electronics interfaces. This paper aims at reviewing how recent innovations in power electronics can open up the potentials for medium and low-voltage DC power (MV/LV DC) development in the future.

Transient analysis of low voltage DC grids with high penetration of DERs

High penetration of Distributed Energy Resources (DERs) with different dynamic responses cause interaction between components in a DC microgrid. This paper proposes a method called object-oriented modeling, which allows analyzing converter-interfaced DC microgrids in steady states and transients. The analysis mainly focuses on transient behavior of external electric values, as well as internal controller states.