Design and Analysis of a New Evaluation Circuit for Capacitors Used in a High-Power Three-Phase Inverter

• Published in: IEEE transactions on industrial electronics (1982) Vol. 63; no. 5; pp. 2679 - 2687
• Main Authors: Hasegawa, Kazunori, Omura, Ichiro, Nishizawa, Shin-ichi
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aging; Capacitance; Capacitors; DC-link capacitors; Density measurement; Design analysis; Direct current; Electric circuits; Failure rates; high-power density; Inductors; Inverters; Power system measurements; Reliability; Ripples; three-phase inverters; three-phase inverters; DC-link capacitors; reliability; high-power density
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2015.2511097

DC-link capacitors in power electronic converters are a major constraint on improvement of power density as well as reliability. Evaluation of the dc-link capacitors in terms of power loss, ageing, and failure rate will play an important role in design stages of the next-generation power converters. This paper proposes a new evaluation circuit for dc-link capacitors used in a high-power three-phase inverter, which is intended for testing power loss, failure rate, ageing, and so on. The evaluation circuit produces a practical ripple current waveform and a dc bias voltage into a capacitor under test, in which the ripple current is equivalent to that generated by the three-phase inverter on the dc link. The evaluation circuit employs a full-scale current-rating and downscaled voltage-rating inverter for producing the ripple current, so that the power rating of the evaluation circuit is much smaller than that of a full-scale current-rating and full-scale voltage-rating inverter. Theoretical analysis and simulated results verify the effectiveness of new evaluation circuit.