DC link capacitors have low ESL, says TDK
TDK has developed the ModCap HF modular capacitor concept for DC link applications. It is able to work at very high switching frequencies and is available as six power capacitors in the B25647A series. They are for rated voltages from 900 to 1600V and cover a capacitance spectrum from 640 to 1,850µF.
Depending on the type, the rated currents range from 160 to 210A with a maximum permitted hot spot temperature of 90 degrees C. The ESL value for ModCap HF is just 8nH and its flat ESR vs frequency evolution minimises losses even at high frequency, said TDK. These characteristics are suitable for fast-switching SiC-based inverters. The very low self-inductance prevents voltage overshooting on the power semiconductors when the current is shut off. Typically, no snubber capacitors are needed.
The ModCap HF types are cubic rather than conventional cylindrical designs. Dimensions are 205 x 90 x 170mm, designed to fit into the new generation of power modules that are compact and maximise power density.
External materials are compliant with fire and smoke standard EN 45545-2 HL3 R23 and UL94 V-0, specially demanded for traction application.
Typical applications are compact converters for traction, renewable energies as well as industrial applications with high switching frequencies.
TDK was established in 1935 to commercialise ferrite, a key material in electronic and magnetic products. Today, its portfolio features passive components such as ceramic, aluminium electrolytic and film capacitors, as well as magnetics, high-frequency and piezo and protection devices. There are also sensors and sensor systems such as temperature and pressure, magnetic, and MEMS sensors. In addition, TDK provides power supplies and energy devices and magnetic heads. Products are marketed under the brands TDK, Epcos, InvenSense, Micronas, Tronics and TDK-Lambda.
TDK focuses on demanding markets in automotive, industrial and consumer electronics, and information and communication technology. The company has a network of design and manufacturing locations and sales offices in Asia, Europe, and in North and South America.
