Extending the company's range of EPCOS MKK power capacitors, TDK announce the MKK DCi-R series B25640 with resin impregnation. Based on the proven MKK DC series with gas impregnation and MKK DC-I with oil impregnation, the series includes capacitors that are rated at up to more than 10 000μF and designed for voltages of up to 4000 V DC.
The energy density of the resin impregnated capacitors is about 10% higher than that of the gas-impregnated types. Moreover, the flat winding technology allows a volume fill factor of about 95% to be achieved, so that highly compact components can be realised.
The 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 design permits ESR values of down to 0.1mΩ and ESL values down to 20nH. The capacitors are self-healing. Their main applications are in large traction converters and HVDC systems.
Thanks to their rugged design, these capacitors are characterised 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 MKK DC-I series assures better heat dissipation from internal hot spots via the capacitor case.