Pareto Optimal DC-Link Capacitor Selection (suplementary data)

Abstract—Due to the wide variety of DC capacitor types, it is challenging to select the best suitable technology for DC links in terms of power loss, volume, and cost. This article presents a capacitor selection process based on Pareto planes in the performance space, considering the needs of a given application. Considered are the operating temperature, lifetime, capacitance decrease over lifetime, derating (due to voltage, temperature and lifetime), and current-carrying capabilities at the respective frequencies. The DC-link capacitor bank design is based on single capacitors in series and parallel connections, fulfilling the individual capacitor specification and the application’s requirement. Since the yielded Pareto plane differs from one application to another, multiple capacitor types with different characteristics must be taken into consideration to fit the respective use case. The Pareto planes shows the benefits of the capacitor technologies (film, electrolytic) for the application. Differences in the design process for each technology are considered. The calculated losses have been validated by measurements for selected capacitor samples. The proposed design process is published as an opensource toolbox.