Abstract
In recent years, E-mobility relevance has increased in the automotive
sector, yet pure electric vehicles struggle to establish themselves in the
still internal combustion engine (ICE) dominated sector of L-category
and powersport applications. Battery electric hybrid L-category
vehicles, as considered in this paper, combine both ICE and electric
powertrains. Nowadays, numerous ICE L-category vehicles use rubber
V-belt continuous variable transmissions (CVT) due to their reliability
and user-friendliness, which often outweighs the drawback of
relatively low efficiency. This paper not only aims to show, with the
help of longitudinal dynamic simulation (LDS), how a state-of-the-art
L-category ICE powertrain with special focus on the CVT can benefit
from hybridization in terms of overall efficiency, but furthermore
points out where the efficiency increase actually comes from and how
this new knowledge can be implemented intelligently into a hybrid
strategy. For this purpose, a Matlab/Simulink forward LDS model of
the vehicle including all its powertrain components is built up. The
research vehicle uses an uncontrolled centrifugal clutch (CC) located
on the input shaft of the CVT. The hybrid module, consisting of a 48V
E-motor, inverter and a battery, is added in parallel hybrid architecture
(P3 configuration) between the CVT output and the driven wheel. In
this study, load on the CVT is increased during ICE driving by using
the E-motor as a generator, while charging the battery at the same time
and using this energy for pure electric driving afterwards. This load
point shifting strategy (LPS) proves to be especially beneficial during
low vehicle speed driving, when both the ICE as well as the CVT load
and thus their efficiency is low. The study shows fuel consumption
benefits of 43% in the WMTC for the considered vehicle, calculated
according to the legislative requirements. Furthermore, the final LPS
hybrid strategy is also tested in other, real-world driving scenarios to
prove its real-world applicability.
sector, yet pure electric vehicles struggle to establish themselves in the
still internal combustion engine (ICE) dominated sector of L-category
and powersport applications. Battery electric hybrid L-category
vehicles, as considered in this paper, combine both ICE and electric
powertrains. Nowadays, numerous ICE L-category vehicles use rubber
V-belt continuous variable transmissions (CVT) due to their reliability
and user-friendliness, which often outweighs the drawback of
relatively low efficiency. This paper not only aims to show, with the
help of longitudinal dynamic simulation (LDS), how a state-of-the-art
L-category ICE powertrain with special focus on the CVT can benefit
from hybridization in terms of overall efficiency, but furthermore
points out where the efficiency increase actually comes from and how
this new knowledge can be implemented intelligently into a hybrid
strategy. For this purpose, a Matlab/Simulink forward LDS model of
the vehicle including all its powertrain components is built up. The
research vehicle uses an uncontrolled centrifugal clutch (CC) located
on the input shaft of the CVT. The hybrid module, consisting of a 48V
E-motor, inverter and a battery, is added in parallel hybrid architecture
(P3 configuration) between the CVT output and the driven wheel. In
this study, load on the CVT is increased during ICE driving by using
the E-motor as a generator, while charging the battery at the same time
and using this energy for pure electric driving afterwards. This load
point shifting strategy (LPS) proves to be especially beneficial during
low vehicle speed driving, when both the ICE as well as the CVT load
and thus their efficiency is low. The study shows fuel consumption
benefits of 43% in the WMTC for the considered vehicle, calculated
according to the legislative requirements. Furthermore, the final LPS
hybrid strategy is also tested in other, real-world driving scenarios to
prove its real-world applicability.
| Original language | English |
|---|---|
| Article number | 2022-32-0018 |
| Journal | SAE Technical Papers |
| DOIs | |
| Publication status | Published - 2022 |
| Event | SETC Small Powertrain and Energy Systems Conference 2022: SETC 2022 - Himeji, Japan, Himeji, Japan Duration: 30 Oct 2022 → 3 Nov 2022 Conference number: 2022 https://www.setc-jsae.com/ |