Optimum design of a single-phase Power Pulsating Buffer (PPB) with PCB-integrated inductor technologies

This paper presents the design procedure for a Buck Power Pulsating Buffer, aimed at optimising the power density of a single phase AC/DC converter. It compares different technologies for the buffer capacitor and for the inductor with printed-circuit board (PCB) integration in mind. As ceramic capacitors are considered (X6S and Ceralink technologies), a non-linear model was developed for the capacitance and ESR variations. This differs from existing literature because film capacitors are usually used and simple models are appropriate for such technologies. Two low-cost, highly integrated inductor technologies are compared. Results allow a fair comparison of these different capacitor and inductor technologies, and it found that the design based on X6S capacitors and planar inductors offers the smaller volume and best efficiency. Moreover, the optimisation procedure favours an original approach, where the converter operates at zero voltage switching (ZVS) along the entire mains period at fixed switching frequency.

I. Introduction

One of the main challenge in power electronics is to design converters with high power density [1]. The development of wide band-gap components allows reducing the volume of power converter. This is mainly due to lower losses and the high switching frequency capabilities of Silicon Carbide (SiC) and Gallium Nitride (GaN) [2]. This, in turn, allows to reduce the thermal management (because of the lower losses), and to use smaller magnetics (because of the higher switching frequency). Passive components, e.g. inductors and capacitors, represent one of the largest share of the overall converter volume, so their reduction is especially important.