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

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 µF 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 voltage 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.