Loss Evaluation of High-Dielectric-Constant-Type Ceramic Capacitors Used in Power Converters

Abstract

To increase the power density of power converters, it is crucial to not only utilize SiC and GaN power devices but also to reduce loss and volume of the passive components. High-dielectric-constant-type ceramic capacitors having high current capacity with small volume are good candidates to be used in high-frequency and high-power-density converters. In terms of a practical designing process, accurate evaluation of the loss characteristics of passive components is critical. However, accurate loss evaluation of ceramic capacitors under practical operating conditions, such as nonsinusoidal high-current conditions, has not been reported. In this study, the loss characteristics of a high-dielectric-constant-type ceramic capacitor are measured by a custom-developed capacitor loss analyzer. As a result of extracting the characteristics of loss from the measurement results, it is suggested that the loss of the sample is dominated by dielectric loss. A new loss calculation method is also studied.