Applications of the solid state transformer concept in the electrical power system

Nowadays the electrical main grid is managed in AC due to several reasons derived from the past. Recent years have experimented a rapid evolution of power electronic components able to dramatically enhance the effectiveness of the active and reactive power flow management. The inverter diffusion makes possible the intelligent integration between systems with different characteristics (i.e. in terms of voltage magnitude and frequency) and the exploitation of generation sources and storage systems typically operating in DC. One of the most interesting components able to interconnect different portions of electrical networks is the Solid State Transformer. The Solid State transformer is formed by few static power converters that operate sinergically and are connected in series with a high frequency transformer. Different voltage levels are made available to achieve high results in terms of system integration, efficiency and flexibility. Taking advantages from the described component structure and main features, in this paper the authors aim to evaluate the main potentials of this technology if widely introduced in the main power system. Starting from the single component description, a couple of possible applications are presented and discussed in terms of assets and weak points.