LC filter optimized design considering the effect on the power converter and capacitor lifetimes

Abstract

AbstractThis work presents an LC filter design methodology that considers the optimization of the converter as a whole: filter, semiconductor switches, and DC bus. The optimization is made in light of the system losses, volume, and the capacitors lifetime, discussing the advantages and disadvantages of decisions in the parametric design of the filter (of the values of L and C). The technology of components and construction challenges are considered in the design. The manuscript guides the design process of the filter in two steps: first, by providing the means to perform the parametric sweep of possible filter designs, according to the converter specifications and other restrictions; second, by describing how the hardware design is carried out and indicating the models and methods that are being used. Individualized analyses for each part of the converter system are made, and using the proposed methodology, three design examples are provided and analyzed, each choosing the filter parameters with different objectives: minimum volume, maximum capacitor lifetime, or maximum efficiency. Results show that using Kool M material results in the lowest filter volumes and losses. It is also shown that for the DC bus design, there is a compromise between volume and lifetime, with a greater number of capacitors increasing both attributes. By designing the system using the proposed methodology, the minimum volume is achieved at an operating point that differs from the individual minimum volumes of the filter and the inverter, and the lifetime is only 1.78% than the maximum lifetime point.