In meshed low voltage DC distribution grids, one of the main challenges is achieving flexible control over the power flow. The most common approach to achieve the full control over the power flow in the meshed DC grid is to deploy DC-DC converters rated for the full power rating of the grid. The drawbacks of this solution are costs and losses of such DC-DC converters. To reduce the costs and the losses from the system standpoint, we introduce a partially rated power flow control converter. This paper presents the control modes of the partially rated power flow control converter and experimentally demonstrates its functionality. The proposed power flow control converter consists of two cascaded converters. On one side the converter is rated for the maximum grid voltage but only a fraction of the grid current and on the other side it is rated for the maximum grid current but only a fraction of the grid voltage. The proposed converter can operate in three modes, and demonstrates the power flow control capability.
Pavel Purgát, TU Delft