Supercapacitor Storage Sizing Analysis for a Series Hybrid Vehicle

Abstract

The increasing interest in Hybrid Electric Vehicles led to the study of new powertrain structures. In particular, it was demonstrated in the technical literature how series architecture can be more efficient, compared to parallel one, if supercapacitors are used as storage system. Since supercapacitors are characterized by high efficiency and high power density, but have low specific energy, storage sizing is a critical point with this technology. In this study, a detailed analysis on the effect of supercapacitor storage sizing on series architecture was carried out. In particular, in series architecture, supercapacitor storage sizing influences both engine number of starts and the energy that can be stored during regenerative braking. The first aspect affects the comfort, whereas the second aspect directly influences powertrain efficiency. Vehicle model and Energy Management System were studied and simulations were carried out for different storage energy, in order to define the optimal sizing.

Turbocompound Power Unit Modelling for a Supercapacitor-Based Series Hybrid Vehicle Application

“…The advantage of using standard driving cycles is that they allow an easier comparison with other studies. However, since downhill are critical for the storage system (in this case supercapacitors), because a large quantity of potential energy should be stored, three additional real missions were simulated, whose data were experimentally acquired in the area of Genoa (Italy) [10,18,40]. In particular, the extra-urban mission is characterized by a long downhill road.…”

“…As a matter of fact, spark ignition engines are today widely employed in the automotive hybrid industry; the reason for this trend is given by their lower local pollutant emission and a higher flexibility in terms of on/off frequency. Nonetheless, firstly, the series architecture can reduce the number of ICE on/offs [22,40], secondly, by slowing down ICE transients, and by working in a limited working area, the local emissions are reduced. To sum up, not only using supercapacitor storage, series architecture becomes more competitive than parallel, but this gap can be even increased with the use of diesel engines.…”

“…As a matter of fact, spark ignition engines are today widely employed in the automotive hybrid industry; the reason for this trend is given by their lower local pollutant emission and a higher flexibility in terms of on/off frequency. Nonetheless, firstly, the series architecture can reduce the number of ICE on/offs [22,40], secondly, Figure 11. ICE work points in the parallel (a), series/parallel (b), and series (c) architecture [22].…”

“…Vehicle longitudinal parameters are reported in Table 5. Supercapacitor storage features are reported in Table 6; a 162-Wh supercapacitor module is used to perform simulations, according to what was presented in [40].…”

A Refined Loss Evaluation of a Three-Switch Double Input DC-DC Converter for Hybrid Vehicle Applications

“…As far as battery storages are concerned, lithium batteries have increased their performance, reaching a key role in hybrid medium size car applications [1][2][3][4][5][6]. On the other hand, many studies have been carried out considering supercapacitor storages on hybrid vehicle, both combining batteries and supercapacitors [7][8][9][10][11][12][13][14][15][16] or using only supercapacitors as the storage system [17][18][19][20][21][22][23][24][25][26][27][28]. Regarding the combined use of batteries and supercapacitors, this configuration matches the pros of both type of storages (i.e., battery high specific energy and supercapacitor high specific power).…”