Guest Editorial Special Section Advances in Research and Applications of Power Electronics in T&D Systems

Electric power networks are experiencing significant changes as a result of widespread adoption of power electronics (PE)-based apparatuses. Power electronics converters are substantially different from synchronous machines which have been used during decades. The different nature of power electronics converters includes some limitations (like very limited overload capability and available inertia) and also some important advantages (like total controllability) which require to completely revise and restructure the way we address the design and analysis of power systems. PE-based converters are present at the generation, transmission, and distribution levels. In the field of power transmission and distribution, HVDC and FACTS technologies have helped to expand network power transfer capability and to increase operation flexibilities over the past 30 plus years. In recent years, more creative (or impactful) innovations in power electronics based T & D apparatus have been emerging. Examples are VSC based HVDC links, PE-based fault current limiters, and solid state transformers. In parallel, various novel PE-application concepts have been proposed and some have found commercial applications. They include, for example, smart wires, electric springs, ground fault neutralizers, soft-open switches, PE-assisted transformers, grid edge PE devices and PE-enabled active protection schemes. As the future power systems will be increasingly populated by power electronics, there is also a need to develop new knowledge on how to understand, analyze and engineer modern and future power systems.