Lifetime Control of Modular Smart Transformers Considering the Maintenance Schedule

Smart Transformers (ST) are power electronic transformers capable of providing grid services and DC connectivity compared to conventional low-frequency transformers. However, failure of the components and consequent maintenance is one of the major challenges compared to it's counterpart, limiting its application. By controlling the power flowing through the cells in a modular ST architecture, the remaining lifetime of these cells can be controlled. The idea is to schedule the maintenance by actively controlling the lifetime of the individual cells using an optimization algorithm. The proposed algorithm has the ability to schedule the maintenances according to predefined maintenance intervals. A potential ST architecture consisting of Cascaded H-bridge (CHB) and Dual-Active Bridge (DAB) converters are analyzed with simulations and experiments to validate the proposed power routing algorithm and its impact on the lifetime and maintenance scheduling.