Journal
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
Volume 8, Issue 3, Pages 2268-2275Publisher
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/JESTPE.2019.2951807
Keywords
Capacitors; Capacitance; Temperature measurement; Voltage measurement; Aging; Capacitance measurement; Ceramics; Capacitors; class 2 ceramic capacitors; resonant switched capacitor circuits; switched capacitor circuits
Categories
Funding
- Stanford SystemX Seedgrant Program
Ask authors/readers for more resources
Class 2 ceramic capacitors, such as X7R, have relatively high energy density compared to Class 1 ceramic capacitors. However, they experience changes due to aging, temperature, and electric field. The measured X7R capacitance drop is 1%-2% per decade hour due to aging, 18% due to a temperature change from 25 degrees C to 125 degrees C, and 75% due to an applied voltage that is 80% of the rated voltage. The measured equivalent series resistance (ESR) of the X7R capacitors shows an increase of 20% to 70% due to aging of 1680 h, and a 50% fluctuation in value when we apply 20% to 80% of the rated voltage. In switched-capacitor (SC) and resonant SC (ReSC) converters, these variations can shift a converter's operating point and result in higher equivalent output resistance and lower efficiency. We quantified the converter performance degradation caused by capacitor variations in the simulation and demonstrated the results by implementing a 1 MHz 25 W 1:4 Dickson ReSC converter. The converter efficiency decreases from 93.1% to 90.7% as a result of capacitor variations mainly due to the aging effect.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available