Power Flow Control Converter for Meshed LVDC

Abstract

Meshed LVDC distribution grid is considered to be more efficient and reliable than AC distribution network.
This applies in particular when there is a significant portion of DC sources, storage, and loads in the grid. Its
optimal operation, however, is not inherent. The power flow in distribution network can suffer from congestion
due to the line impedance of the system. Thus, a device that can regulate the power flow is regarded
important. Several works have proposed DC-DC transformer and series voltage source type of power flow
control device for HVDC application. DC-DC transformer, however, needs to be rated at full grid power.
Meanwhile, series voltage source type for HVDC requires an additional connection to either nearby AC network
or other lines. This thesis presents a function and requirements validation of a novel power flow control
converter (PFCC) which only requires partial power rating with respect to the grid rating, needs no additional
connection to other lines, and can regulate power flow in four V-I quadrants. The proposed topology able
to performs power regulation with a fraction of grid power in all of the quadrants both in simulation and
experiment.