Output ripple reduction of an automotive multi-phase bi-directional dc-dc converter

Abstract

Bi-directional dc-dc converters for automotive applications typically are limited to generate only a small voltage ripple, especially when a ultra-capacitor with a limited ripple current capability is interfaced by the converter. Thus, to minimize the ripple quantities and the converter volume at the same time, interleaved multi-phase dc-dc converters are utilized. However, tolerances of the buck+boost inductors of the interleaved phases generate sub-harmonics in the ripple spectrum that are counterproductive to the advantage of ripple reduction. A method to cancel the fundamental frequency of the voltage ripple is proposed that is applicable to a converter consisting of three or more phases. It is shown that even for a low phase count the overall ripple amplitude is greatly reduced, only by adjustment of the phase shift angles. Experimental results carried out with a three-phase interleaved bi-directional dc-dc converter proof the concept functionality.

Novel 3 level bidirectional buck converter with wide operating range for Hardware-in-the-Loop test systems

“…9 the remaining ripple is depicted for one inductor with a lower inductance of L 1 = 17 μH and the other ones at the nominal value of 20 μH and a low pass filter at f g = 60 kHz. While the cancelation of the 1st harmonic and the in [10] proposed method is nearly the same, the cancelation of the 2nd and 3rd harmonics reduces the ripple by app. 20 %.…”

“…Beside the fact, that this algorithm is only applicable to odd numbers of submodules the ripple cancelation is not optimal. In [10] an enhanced algorithm is proposed, which uses the sorting algorithm of [9] for N − 2 modules and cancels the remaining ripple by vectorial addition of the last two submodule current ripple vectors.…”

“…The peak compensation method is proposed in[10] while the harmonics cancelation is done by minimizing (4) for N = 1, N = 2 and N = 3.…”

Comparative evaluation of soft-switching concepts for bi-directional buck+boost dc-dc converters

“…With simplified equations for the switching times t i and the phase current given in [23], the relative phase current error of the the CF-ZVS-M converter is calculated from…”

Asymmetric interleaving in low-voltage CMOS power management with multiple supply rails

“…Asymmetric phase-shifting has been used to account for imbalances in the converter phases due to component tolerances [21]. This was done for standard single-input single-output converter topologies such as shown in Fig.…”