Power flow controllers (PFCs) might be needed in highly meshed High-voltage direct current (HVDC) systems to redistribute the current and power in the various cables. This paper introduces two new unidirectional topologies, which are among the most simple PFC topologies. It describes the working principle, electrical characteristics, various fault cases, and the corresponding protection circuits in detail. Experiments have been conducted on a scaled-down prototype to verify the full-scale HVDC system simulations. Discussion and extension of the PFC with more than two transmission lines are provided.

With the increase in penetration of power electronic converters in the power systems, a demand for overcurrent/ overloading capability has risen for the fault clearance duration. This article gives an overview of the limiting factors and the recent technologies for the overcurrent performance of SiC power modules in power electronics converters. It presents the limitations produced at the power module level by packaging materials, which include semiconductor chips, substrates, metallization, bonding techniques, die attach, and encapsulation materials. Specifically, technologies for overcurrent related temperatures in excess of 200 degrees C are discussed. This article also discusses potential technologies, which have been proven or may be potential candidates for improving the safe operating area. The discussed technologies are use of phase-change materials below the semiconductor chip, Peltier elements, new layouts of the power modules, control and modulation techniques for converters. Special attention has been given to an overview of various potential phase-change materials, which can be considered for high-temperature operations.