Experimental Validation of Hydrogen Fuel−Cell and Battery−Based Hybrid Drive without DC−−DC for Light Scooter under Two Typical Driving Cycles

Faced with key obstacles, such as the short driving range, long charging time, and limited volume allowance of battery−−powered electric light scooters in Asian cities, the aim of this study is to present a passive fuel cell/battery hybrid system without DC−−DC to ensure a compact volume and low cost. A novel topology structure of the passive fuel cell/battery power system for the electric light scooter is proposed, and the passive power system runs only on hydrogen. The power performance and efficiency of the passive power system are evaluated by a self−developed test bench before installation into the scooters. The results of this study reveal that the characteristics of stable power output, quick response, and the average efficiency are as high as 88% during the Shanghainese urban driving cycle and 89.5% during the Chinese standard driving cycle. The results present the possibility that this passive fuel cell/battery hybrid powertrain system without DC−DC is practical for commercial scooters.

Evaluation of energy consumption in the acceleration process of a passenger car

The analysis of the vehicle acceleration process is a current topic based on the aspects related to the general characteristics of the car, its parameters, design, drive unit performance, and the influence of external factors. Therfore in the article, the authors assessed the dynamic and energy parameters of the car motion, in which the intensity of acceleration of the car with different intensities was examined. Acceleration was carried out in two variants, the first for a normal internal combustion engine and the second for the same engine but additionally equipped with a short-term boost system. In this way, it influences the increase in power and energy in the car drive system, changing its acceleration intensity. Variable car acceleration intensity was obtained in the range from 0.12 to 1.37 m/s2 , and energy consumption at the level of 0.4 to 1.2 MJ in the distance of 1/4 mile. The article proposes a combination of energy parameters and engine power in order to assess the acceleration dynamics, for this purpose, the specific energy consumption of the car was determined, ranging from 0.35 to 2.0 J/(kg∙m), which was related to the engine power, denoting it with the dynamics index. The study focuses on the assessment of the relationship between the specific energy consumption and acceleration of passenger cars in the available powertrain system using a new dynamics index. The proposed dynamics index combines the energy and dynamic parameters of the car to be able to objectively quantify the acceleration process.

Design and Analysis of 2-Stage Gearbox for ATV Applications

The main objective of this project is to design and develop a 2-Stage- Reduction gearbox for all terrain vehicles application. Gearbox is a mechanical unit consisting of series of gears within a housing (casing) or a simple gear train. It is the main component of the powertrain system as it provides speed and torque conversions from the Engine or CVT to the wheels. The gears inside of gearbox can be any one of a number of different types of the gear that are available in the market i.e., from spur gears to worm gears and planetary gears as well. In this report the gearbox is made from a helical gear train. This report focuses on selection of overall reduction ratio of the gearbox, material selection, selection of gear dimensions, selection of shaft dimension, design of key and bearing selection from SKF bearing catalogue. The bending and wear strengths are calculated to determine factor of safety and later, Finite element analysis is performed to validate the results. Keywords: Geartrain, Shaft Design, SKF Bearings, Solidworks, FEA

Thermal Profiling of Automotive Turbochargers in Durability Tests

A major portion of the development of an automotive powertrain system is devoted to robustness and durability testing to ascertain the viability of the design. For turbochargers, thermo-mechanical fatigue is often considered as life limiting failure mechanism for the turbine section, therefore, these tests involve repeated and continuous cycling of the turbocharger for hundreds of hours. The Thermal History Coatings (THC) can offer a new and unique solution. THCs are applied to the surface of a component and, when heated, the coating permanently changes according to the maximum temperature of exposure. The technique has been used in several turbomachinery, and other applications to capture the spatial temperature distribution of critical components. However, the turbocharger durability test presents new challenges for the technique. It has not been tested in this type of application and repeated cycling operation can test the response of the coating on the temperature measurements. In this paper, the capability of the THC for this application was investigated. For the first time, the effect of cyclic operation on the THC is reported. The measurement capability was demonstrated on two turbine housings tested on a gas stand, one for a single cycle, another for 10 cycles. The results show that the surface temperature profile of the two turbine housings can be accurately recorded and the results are validated against the installed thermocouples. The demonstration indicates that the THC can be used to acquire accurate and detailed spatial temperature distributions. This information improves the interpretation of a durability test.

Modern trends in development of alternative powertrain systems for non-road machinery

Continuously increasing excessive emission of exhaust gases from motor vehicles, and specifically internal combustion engines have been recognized as a major concern by most of the industrialized countries since mid- 1960s. Emission gases containing an air pollutants have been shown to impose variety of negative effects on public health and the natural environment. This leads to introduction of variety of different, alternative powertrain system solutions which could help in reduction of powertrain generated emissions. Mentioned reduction of pollutants generated by the machine can be reached by application of different powertrain system or improved utilization and control of the existing one. Several different types of solutions have been considered over years as a concepts, prototypes or trial versions. Significant intensification of recent work across the globe have led the manufacturers to get their systems to the market pre-introduction or introduction stages. Alternative powered non-road machinery, either full electric, hybrid, fuel cell, or electrified have been already presented and successfully introduced. This paper focuses on state of the art non-road machinery alternative powertrain solutions and its applications, either specific or with a nature of general purpose machine. Variety of powertrains have been presented with attention to their operational parameters and working principles. Research involves in depth considerations of energy transfer within different components of the powertrain and the entire machine.

Analysis of the selection of chosen technical parameters of the powertrain system for a diesel-electric rail-road tractor

The article presents the results of a simplified analysis of the feasibility of designing a rail chassis of a two-way tractor with an internal combustion or electric drive. Basic traction and operating parameters have been assumed for which the road-rail tractor could operate in an effective manner. On their basis, strength calculations were carried out and mechanical elements of the drive system meeting the required assumptions were selected. All the calculations presented in the text were fulfilled. The technical feasibility of building the mechanical part of the rail running gear of a rail-road tractor driven by an internal combustion engine or electric motors has been demonstrated.

Physics-Based and Data-Enhanced Model for Electric Drive Sizing during System Design of Electrified Powertrains

In multi-drive electrified powertrains, the control strategy strongly influences the component load collectives. Due to this interdependency, the component sizing becomes a difficult task. This paper comprehensively analyses different electric drive system sizing methods for multi-drive systems in the literature. Based on this analysis, a new data-enhanced sizing approach is proposed. While the characteristic is depicted with a physics-based polynomial model, a data-enhanced limiting function ensures the parameter variation stays within a physically feasible range. Its beneficial value is demonstrated by applying the new model to a powertrain system optimization. The new approach enables a detailed investigation of the correlations between the characteristic of electric drive systems and the overall vehicle energy consumption for varying topologies. The application results demonstrate the accuracy and benefit of the proposed model.