Flexible Large Power Solid State Transformer (FLP-SST)

Abstract

A large power transformer (LPT) is a major component in the electric power system grid. With the passage of time their reliability in terms of failure and service maintenance has been a big concern. According to a report by EPRI, various agencies have emphasized, and recent events have demonstrated, the critical nature of power transformers in the face of possible high-impact, low-frequency (HILF) events. The HILF events include intentional malicious events (e.g., physical attacks, cyber-attacks, coordinated attacks, electromagnetic pulse weapons, and others), natural disasters (e.g., hurricanes, earthquakes, severe geomagnetic disturbances, etc.), and non-intentional or accidental events such as nuclear power plant accidents. With aging, the line frequency transformers (LFTs) are also prone to failure due to insulation degradation, coolant leakage, mechanical failure, inadequate maintenance, etc. and thus poses a bigger threat to the electrical grid. Moreover, these transformers are custom made to fit the needs at the substation and weighs approximately between 100-400 tons, hence are neither interchangeable nor stored as a spare one. Hence reasonable efforts need to be made regarding the replacement of the LPT with a more feasible technology that does not pose similar issues. The concept of Flexible Large Power Solid-State Transformer (FLPSST) has addressed the aforementioned issues to provide an economical solutions for the failure of LPTs.