Extended-Range Power Capacitors with Higher Energy Density

TDK Corporation has extended its range of EPCOS MKK power capacitors. The new MKK DCi-R series B25640 with resin impregnation is based on the proven MKK DC series with gas impregnation and MKK DC-I with oil impregnation. The new series features capacitors that are rated at up to more than 10,000 µF and designed for voltages of up to 4000 Vdc. The energy density of the new resin impregnated capacitors is about 10 percent higher than that of the gas-impregnated types. Moreover, the flat winding technology allows a volume fill factor of about 95 percent to be achieved, so that highly compact components can be realized.

As a result of their rugged design, these capacitors are characterized by their high current capability and their ability to withstand high voltage and current peaks. In addition, the more highly developed internal structure of the new MKK DC-I series assures better heat dissipation from internal hot spots via the capacitor case.

The new improved MKK DCi-R capacitors satisfy even the most demanding requirements on reliability and enable an operating life of up to 40 years with failures in time (FIT) of less than 100. Depending on the type, the new design permits ESR values of down to 0.1 mΩ and ESL values down to 20 nH. The new capacitors are self-healing. Their main applications are in large traction converters and HVDC systems.

Main applications for these high energy density capacitors include traction converters and HVDC systems. Features and benefits include: Energy density 10 percent higher than that of gas-impregnated types; Capacitance values of up to more than 10,000 µF; Voltages of up to 4000 Vdc; Low ESR values and ESR values down to lower limits of 0.1 mΩ and 20 nH; Ability to withstand high voltage and current peaks; and High current capability.