On the Protection of the Power Flow Control Converter in Meshed Low Voltage DC Networks

Abstract

The two main challenges of meshed low voltage DC grids today are the flexible control of power flow and the short-circuit protection. The conventional approach to deal with both problems is to incorporate galvanically isolated DC-DC converters with integrated short-circuit protection, which are rated for the full power rating of the grid. In this paper, we describe an approach based on the combination of a converter which has a partial power rating with respect to the grids power rating and a circuit breaker with full rating with respect to the grid. Based on the review of abnormal operating conditions of the power flow control converter and its requirements on protection. We propose a new protection strategy for the power flow control converter and evaluate the applicable circuit breaker technologies based on the review of the protection requirements.