TDK Corporation presents the EPCOS RingCap – a power capacitor with an innovative design that is especially suitable for xEV applications. Thanks to its ring configuration, the new RingCap can be integrated into a clutch bell housing or wheel hub motors. The dimensions of the capacitor can be adapted according to the specific requirements of the customer: The outer diameter may be up to 315 mm, while its width is no more than 50 mm. The EPCOS RingCap is designed for rated voltages of between 100-Vdc and 900-Vdc and offers capacitance values of between 100 µF and 2000 µF.
Apart from the main winding, Y-capacitors with separate terminals can additionally be integrated in the winding. A special heat-treatment under vacuum increases long-term stability of the capacitor. In the standard version with dielectric made of polypropylene (PP) or polyethylene terephthalate (PET), the capacitor is suitable for a temperature range between -40 and +105 degrees C. With a dielectric made of polyethylene naphthalate (PEN), it can even handle temperatures of up to +150 degrees C.
Due to the low equivalent series inductance (ESL) values ranging from less than 10 nH up to 30 nH, no unwanted overvoltages occur in the dc link circuit during high-speed switching operations. For better protection against environmental effects, the capacitor is also available with a resin-filled housing.