Anti-ferroelectric MLCCs with high energy density for DC link applications

Inhalt:
DC link capacitors are critical components in many power electronic applications. The required properties are covered by different component technologies. Especially in the range of approximately 1 – 10 muF and 0.1 – 1 kV, aluminium electrolytic capacitors, film capacitors and ferroelectric multilayer ceramic capacitors (MLCC) are in competition. Compared with these, anti-ferroelectric MLCCs have outstanding properties in terms of capacitance density, capacitance over volt-age behaviour, losses, temperature stability, equivalent series inductivity (ESL), and equivalent series resistivity (ESR), but to higher costs. Thanks to new anti-ferroelectric material compositions with enhanced permittivity and switching field strength, the energy density can be significantly increased by a factor of approximately 2.86 leading to reduced component size and costs.