Building blocks for meshed LVDC systems

Abstract

Low voltage direct current (LVDC) became a viable option for electric energy distribution in the early years of the twenty-first century. The upturn in the use of LVDC is fuelled by advances in power electronics and the growing use of renewable energy sources (RES) and electric storage. This work focuses on the power electronic devices for the LVDC systems as the primary instruments that implement the system functionalities. The primary function of any power distribution system is to efficiently and safely deliver power from the sources to the loads. As is also discussed in this thesis, LVDC is exceptionally well suited to fulfill this goal in systems with bidirectional power flow that consist of multiple sources and multiple loads. Secondly, the system must be able to identify, isolate, and clear system failures that inevitably occur during the operation. Therefore this thesis focuses on the role of power electronics in two main application areas - power flow control and short-circuit protection.