Jianghai Europe offers screw terminal electrolytic capacitors with efficient bottom cooling for high‑power DC link applications.
A widely used method for thermal management in large power converters is active water cooling, where the cooling circuit typically passes first through the DC link capacitors and then through the power semiconductors. By integrating the capacitors directly into the cooling path, system designers can significantly reduce hotspot temperatures and improve overall reliability of the DC link stage.
Aluminium electrolytic capacitors are particularly suited to this concept because of their intrinsic anisotropic thermal behaviour: due to the winding structure, thermal conductivity in the axial direction is several times higher than in the radial direction. The anode and cathode foils act as efficient heat spreaders, transporting the power losses generated in operation towards the bottom of the can, where they can be extracted via a cold plate or heat sink.
Bottom Cooling With Extended Cathode Design
The Jianghai screw terminal capacitors exploit this axial heat flow by using an extended cathode design that improves the thermal path between the winding and the can bottom. The protruding cathode winding creates a low‑resistance thermal interface to the aluminium base, reducing the temperature rise of the active element under high ripple current and high ambient conditions.
This bottom‑cooling approach allows system developers to decouple electrical and thermal design constraints more effectively. Higher permissible ripple currents or increased ambient temperatures can be accommodated without oversizing the capacitor bank, often leading to fewer components, a smaller footprint, and lower total cost of ownership at system level.
Optimized Thermal Interface To The Heat Sink
For best performance, the heat transfer between the capacitor bottom and the heat sink or cold plate is optimized using thermally conductive interface materials such as pads, foils, or adhesives. In combination with sufficient mechanical clamping force, these materials minimize contact thermal resistance and ensure stable, reproducible cooling conditions over the full service life.
To simplify integration, Jianghai can manufacture the cans with a dedicated embossing and a circumferential metal ring just above the bottom area. This mechanical feature helps designers to apply a defined contact pressure, supports automated assembly processes, and contributes to robust, vibration‑resistant mounting in demanding industrial and traction environments.
Benefits For Demanding DC Link Applications
The screw terminal capacitors with bottom cooling are aimed at applications where very high DC link performance and reliable heat removal are key design drivers. Typical use cases include large drives, wind and solar inverters, traction converters, and other power conversion systems that already employ water or liquid cooling to handle elevated power densities.
- Higher permissible ripple current and power density thanks to efficient bottom cooling.
- Reduced capacitor core temperature, contributing to longer expected lifetime and improved reliability.
- Potential reduction in the number of capacitors required, supporting more compact DC link layouts.
- Mechanical features enabling secure mounting and consistent thermal contact in series production.
Customer‑Specific Configurations And Cost Efficiency
Jianghai offers these bottom‑cooled screw terminal electrolytic capacitors as customer‑specific variants within the boundaries of what is technically feasible for the respective series and can size. Electrical ratings, mechanical dimensions, and interface details can be adapted to match individual system requirements, as long as they remain within the platform’s design window.
The customized capacitors combine tailored technical solutions with competitive cost efficiency and are available starting from the minimum order quantities specified in the Jianghai catalogue. This makes application‑optimized thermal management accessible not only for large‑volume projects, but also for specialized industrial systems and OEM platforms seeking a differentiated DC link design.
Source: Jinghai-Europe
