What is a solid-state transformer and what are its potential applications?

A solid-state transformer (SST) replaces conventional transformers with power electronics, enabling: voltage transformation via high-frequency (kHz) transformer (smaller/lighter), voltage regulation, reactive power control, harmonic isolation, and DC connectivity. Typical architecture: AC-DC (active rectifier) - isolated DC-DC (DAB) - DC-AC (inverter). Applications include: grid integration of renewables and storage, EV fast charging with integrated DC output, data centers, and traction systems. Challenges: efficiency (must compete with 99%+ transformer), cost, reliability, and protection. SST is key enabler for smart grid and DC microgrids.