Hybrid electric powertrains in automotive applications aim to improve emissions and fuel economy with respect to conventional internal combustion engine vehicles. Variety of design scenarios need to be addressed in designing a hybrid electric vehicle to achieve desired design objectives such as fuel consumption and exhaust gas emissions. The work in this paper presents an analysis of the design objectives for an automobile powertrain with respect to different design scenarios, i. e. target drive cycle and degree of hybridization. Toward these ends, four powertrain configuration models (i. e. internal combustion engine, series, parallel and complex hybrid powertrain configurations) of a small vehicle (motorized three wheeler) are developed using Model Advisor software and simulated with varied drive cycles and degrees of hybridization. Firstly, the impact of vehicle power control strategy and operational characteristics of the different powertrain configurations are investigated with respect to exhaust gas emissions and fuel consumption. Secondly, the drive cycles are scaled according to kinetic intensity and the relationship between fuel consumption and drive cycles is assessed. Thirdly, three fuel consumption models are developed so that fuel consumption values for a real-world drive cycle may be predicted in regard to each powertrain configuration. The results show that when compared with a conventional powertrain fuel consumption is lower in hybrid vehicles. This work led to the surprisingly result showing higher CO emission levels with hybrid vehicles. Furthermore, fuel consumption of all four powertrains showed a strong correlation with kinetic intensity values of selected drive cycles. It was found that with varied drive cycles the average fuel advantage for each was: series 23 %, parallel 21 %, and complex hybrids 33 %, compared to an IC engine powertrain. The study reveals that performance of hybrid configurations vary significantly with drive cycle and degree of hybridization. The paper also suggests future areas of study.

Millions of three-wheelers in large cities of Asia and Africa contribute to the already increasing urban air pollutants. An emerging method to reduce adverse effects of the growing three-wheeler fleet is hybrid-electric technology. The overall efficiency of a hybrid electric vehicle heavily depends on the power management strategy used in controlling the main powertrain components of the vehicle. Recent studies highlight the need for a comprehensive report on developing an easy-to-implement and efficient control strategy for hybrid electric three-wheelers. Thus, in the present study, a design methodology for a rule-based supervisory controller of a pre-transmission parallel hybrid three-wheeler based on an optimal control strategy (i.e., dynamic programming) is proposed. The optimal control problem for minimizing fuel, emissions (i.e., HC, CO and NOx) and gear shift frequency are solved using dynamic programming (DP). Numerical issues of DP are analyzed and trade-offs between optimizing objectives are presented. Since DP strategy cannot be implemented as a real-time controller, useful strategies are extracted to develop the proposed rule-based strategy. The developed rule-based strategy show performance within 10% of the DP results on WLTC and UDC-NEDC drive cycles and has the clear advantage of being near-optimal, easy-to-implement and computationally less demanding.

<p>Hairpin winding technology, combined with direct oil jet impingement cooling, is a viable solution known to increase volumetric power density and efficiency in the next generation of traction motors. However, the coolant fluid interaction with the complex winding geometry has not yet been fully examined; specifically, with the use of high-fidelity CFD simulations. Thus, the present work investigates the radial and axial oil impinging jets in a hairpin winding motor using multi-phase simulation. The study first analyses power losses and temperature distribution of the motor under the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). Next, the performance of axial and radial jet impingement is numerically analysed by considering the fluid flow. Finally, the two configurations are compared in terms of their oil film formation rate. The results indicate that the maximum power losses observed in typical driving conditions are considerably lower than the maximum losses predicted for the complete operational region of the motor. Moreover, the axial impinging jet shows a higher oil film formation rate compared to a radial jet impingement configuration within the examined conditions.</p> <p><br></p> <p>Manuscript accepted to publication in WEMDCD 2023 IEEE conference. </p> <p><br></p> <p> © 20XX IEEE.  Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. </p>

<p>Hairpin winding technology, combined with direct oil jet impingement cooling, is a viable solution known to increase volumetric power density and efficiency in the next generation of traction motors. However, the coolant fluid interaction with the complex winding geometry has not yet been fully examined; specifically, with the use of high-fidelity CFD simulations. Thus, the present work investigates the radial and axial oil impinging jets in a hairpin winding motor using multi-phase simulation. The study first analyses power losses and temperature distribution of the motor under the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). Next, the performance of axial and radial jet impingement is numerically analysed by considering the fluid flow. Finally, the two configurations are compared in terms of their oil film formation rate. The results indicate that the maximum power losses observed in typical driving conditions are considerably lower than the maximum losses predicted for the complete operational region of the motor. Moreover, the axial impinging jet shows a higher oil film formation rate compared to a radial jet impingement configuration within the examined conditions.</p> <p><br></p> <p>Manuscript accepted to publication in WEMDCD 2023 IEEE conference. </p> <p><br></p> <p> © 20XX IEEE.  Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. </p>

Hairpin winding technology, combined with direct oil jet impingement cooling, is a viable solution known to increase volumetric power density and efficiency in the next generation of traction motors. However, the coolant fluid interaction with the complex winding geometry has not yet been fully examined; specifically, with the use of high-fidelity CFD simulations. Thus, the present work investigates the radial and axial oil impinging jets in a hairpin winding motor using multi-phase simulation. The study first analyses power losses and temperature distribution of the motor under the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). Next, the performance of axial and radial jet impingement is numerically analysed by considering the fluid flow. Finally, the two configurations are compared in terms of their oil film formation rate. The results indicate that the maximum power losses observed in typical driving conditions are considerably lower than the maximum losses predicted for the complete operational region of the motor. Moreover, the axial impinging jet shows a higher oil film formation rate compared to a radial jet impingement configuration within the examined conditions.