TDK has introduced the B25696H series, a family of MKP DC-link film capacitors engineered for the higher switching frequencies and faster voltage transitions of SiC-based power converters. The series covers capacitance values from 47 µF to 1280 µF across rated DC voltages from 900 V to 2,000 V, designed for energy storage systems, traction drives, solid-state transformers and renewable energy inverters.

SiC switches at dv/dt rates that silicon IGBTs can’t approach, and that speed makes DC-link capacitor parasitic inductance the dominant source of voltage overshoot at turn-off. The B25696H uses an internal busbar configuration that distributes current uniformly across the capacitor windings, achieving ESL as low as 30 nH. ESR comes in at 0.8 mΩ at 10 kHz with good stability up to 100 kHz, which matters for accurate loss budgeting at the switching frequencies SiC enables. Ripple current capability reaches up to 91 A at 60° C ambient and 10 kHz.

The cylindrical aluminum-cased units use metallized polypropylene dielectric with self-healing properties. Two diameters are available—85 mm and 100 mm—with M6 screw terminals and an M12 mounting bolt. Operating temperature range is −40° C to +85° C hotspot. Baseline lifetime is 100,000 hours at 75° C and rated voltage, extendable to 200,000 hours through voltage and temperature derating.

TDK offers a free online CapThermal simulation tool for thermal behavior modeling and lifetime estimation under application-specific conditions.

Source: TDK Electronics