TDK Launches High-Temperature ModCap UHP Capacitor Series

TDK Corporation has introduced the ModCap UHP series of DC link capacitors, engineered for continuous operation at hotspot temperatures up to 105 °C without derating. This development addresses increasing demands on the digital supply chain for power electronics in applications such as renewable energy, energy storage, industrial drives and traction converters where high current density and thermal resilience are required.

Targeting Elevated Thermal and Electrical Demands in Power Conversion
As power electronic systems evolve, particularly those incorporating silicon carbide (SiC) semiconductors, DC link capacitors must operate reliably under higher thermal and electrical stress while maintaining compact form factors. Traditional polypropylene capacitors typically require derating above 90 °C, reducing effective capacitance or lifetime under continuous high-temperature conditions. The ModCap UHP series extends this threshold to 105 °C without derating, enabling designers to sustain rated performance under elevated hotspot temperatures common in high-current converters.

The series employs a new high-temperature dielectric coupled with a modular architecture to support extended operational lifetime and improved electrical performance. TDK specifies a lifetime of 200,000 hours at 105 °C, with current density approximately 20 percent higher than earlier ModCap designs. Voltage ratings span 1350 V to 1800 V with capacitances from 470 µF to 880 µF, targeting use with SiC power switches where low equivalent series inductance (8 nH) and high-frequency handling are needed.

Design Integration and Application Areas
The cubic package (205 × 90 × 170 mm) facilitates integration into DC link structures with busbar mounting, supporting higher converter power density and simplifying layout. Low inductance and modular design reduce reliance on auxiliary snubber components, aligning with trends in compact converter topologies. Key application areas include central inverters for renewable installations (solar and wind), electrolyzers for hydrogen production, energy storage systems, auxiliary traction drives and industrial motor drives that require sustained DC link performance under thermal loads.

In addition to electrical specifications, the series incorporates sustainability and safety considerations: its dielectric film uses ISCC-certified bio-circular BOPP material, and the housing meets UL94 V-0 and EN 45545-2 HL3 R23 fire safety standards. TDK provides associated design and simulation support via SPICE models and web-based tools for life, rating and thermal analysis.

Technical Context within Capacitor Selection for Power Electronics
Capacitors in DC link roles buffer energy and smooth voltage in high-power conversion stages; their performance directly impacts converter efficiency, thermal management and lifespan. Operating thresholds for temperature and current density are critical parameters in selecting capacitors for SiC-based inverters and similar high-frequency, high-power applications. The ModCap UHP’s ability to maintain rated operation at 105 °C without derating places it at the higher end of this performance spectrum, addressing thermal challenges without compromising electrical characteristics.

By extending the permissible operating temperature and enhancing current density while retaining low inductance and modular integration, TDK’s ModCap UHP series advances DC link capacitor capabilities for demanding power electronics sectors. Its combination of long lifetime, thermal resilience and engineering support tools positions it for adoption in renewable energy, industrial and traction power conversion systems where reliability under continuous high-load conditions is imperative.

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