Low ESL in DC link capacitor for new IGBT modules

August 19, 2016 // By Nick Flaherty
TDK has developed a DC link capacitor specifically designed for the HybridPACK 1-DC6 IGBT module from Infineon Technologies.

The combination of the EPCOS B25655P4607J021 and the IGBT module enables the design of extremely compact inverters for xEV applications or for use as industrial inverters.

The link capacitor has a rated voltage of 450 V DC and offers a capacitance of 600 µF. It has six busbar terminals with dimensions that are matched precisely to fit the IGBT module, and this multiple contacting produces an excellent current capability while at the same time offering very low parasitics. As a result the ESR has a maximum value of 0.6 mΩ and the ESL value is just 25 nH. The low ESL means voltage peaks on switching off the IGBTs are almost completely eliminated.

The current capability is 150 A at a maximum ambient temperature of 105°C and a cooled temperature on the underside of 75°C. The component is designed using power capacitor chip (PCC) technology where the capacitor element is constructed as a stacked winding, with which a volume fill factor of nearly 1 is achieved. The dimensions of the housing are correspondingly compact, at just 140 mm x 72 mm x 50 mm.

A flat winding version is also available in the same housing (B25655P4477J121) with a capacitance of 470 µF for  450 V DC. At a maximum ambient temperature of 105°C and a cooled temperature on the underside of 75°C, its current capability is also  150 A. The ESR value of this design is 0.8 mΩ and the ESL is 25 nH.

The capacitor is also available with an additional connection for the EPCOS high-voltage DC EMC filter.

Further information on the products can be found under  www.epcos.com/pec