Design and simulation of high-performance hybrid electric vehicle powertrains

The intent of this study was the design, modeling, and simulation of several high-performance light-duty hybrid electric vehicle powertrains. The design requirements of each proposed configuration are to meet or exceed a set of performance baselines based on a composite set of particular high-performance conventional vehicles presently available, while demonstrating increased fuel efficiency over regulated government cycles.;Several hybrid powertrain configurations were studied; however, the most promising and feasible for production designs were selected for further modeling. All of the proposed designs are post-transmission parallel hybrids for primarily performance reasons, with the auxiliary motive power coming after the transmission, utilizing a modeled spark-ignited, Variable Valve Timing (VVT) equipped internal combustion engine. A control strategy has been developed for the operation of these powertrains for virtually any driving condition---the strategy was not optimized for any particular government regulated cycle. Computer simulations were performed to simulate both the performance and the fuel economy of the proposed vehicle designs.;The simulation results show that the fuel economy of the modeled hybrid vehicles exceeds that of the comparable conventional vehicles, as well as meeting or exceeding the performance requirements of the baseline vehicles by 12--23%. In addition the exhaust gas emissions may be reduced, compared to a conventional vehicle due to hybridization. All modeled components were selected from available off-the-shelf applications, and the selected designs were chosen to be readily mass-produced

Optimal power management of hybrid electric vehicles through drivetrain analysis

The inefficient performance of gasoline-engine based vehicles along with high emissions and fuel consumption can be improved through utilization of hybrid electric vehicles (HEVs). The multiple power and energy sources in the hybrid drivetrain can be well managed through an appropriate control strategy that supervises the power distribution. While doing so, the control strategy needs to operate every component optimally in addition to overseeing controlled charge-discharge of battery to obtain efficient energy usage. In this thesis an algorithm has been developed for efficient power division among the various components of a series-parallel (S-P) drivetrain. It has been designed to manage the power flow with the least possible losses while keeping fuel economy at an optimum level and maintaining battery state-of-charge (SOC) in a pre-defined range. The importance of optimizing both engine and motor has been discussed. Analysis has also been presented to show possible benefit of using diesel instead of gasoline engine for hybrid vehicles

Study of challenges in technology development and market penetration of hybrid electric vehicles in Canada

Growing concerns of the economic and environmental impact of petroleum combustion by on-road transportation have accelerated the development of alternative fuel vehicles; of these, the hybrid electric vehicle (HEV) is currently the most commercially successful technology. It integrates an electric drivetrain to the internal combustion engine for optimized engine operation giving significantly higher fuel efficiency and lower emissions. However, despite their well recognized benefits, Canadian consumers have shown reluctance in adapting HEVs so far. This thesis discusses the immediate need for Canada to adopt more efficient and eco-friendly transportation systems and analyzes the cost effectiveness and tailpipe emissions of HEVs that offer a suitable alternative. The factors inhibiting market acceptance of hybrids are have been reviewed and a set of comprehensive policy guidelines and measures have been proposed to provide financial incentives, enforce emission regulations and support technology development of hybrid vehicles. As part of the highlighted target, challenges in key areas of HEV technology have been discussed and one such challenge is addressed by proposing a more robust electric motor drive for vehicle traction

Comparative fuel economy, cost and emissions analysis of a novel mild hybrid and conventional vehicles

© IMechE 2017. Mild hybrid vehicles have been explored as a potential pathway to reduce vehicle emissions cost-effectively. The use of manual transmissions to develop novel hybrid vehicles provides an alternate route to producing low cost electrified powertrains. In this paper, a comparative analysis examining a conventional vehicle and a mild hybrid electric vehicle is presented. The analysis considers fuel economy, capital and ongoing costs and environmental emissions, and includes developmental analysis and simulation using mathematical models. Vehicle emissions (nitrogen oxides, carbon monoxide and hydrocarbons) and fuel economy are computed, analysed and compared using a number of alternative driving cycles and their weighted combination. Different driver styles are also evaluated. Studying the relationship between the fuel economy and driveability, where driveability is addressed using fuel-economical gear shift strategies. Our simulation suggests the hybrid concept presented can deliver fuel economy gains of between 5 and 10%, as compared to the conventional powertrain

Development of a modular dual engine hybrid electric vehicle simulation model

Depleting resources of fossil fuel, climate change impacts, high oil prices, and strict emission requirements are leading to the research on efficient, environmentally friendly, and lowered fossil fuel dependent solutions in the transportation field. While a number of studies used computer modeling and simulation tools to investigate hybrid electric vehicles (HEVs), very few attempted to model and simulate a dual-engine hybrid vehicle. Designing a vehicle engine to meet energy needs in the fully loaded condition is not an optimal solution for manufacturers and customers. The larger the engine, the higher the manufacturing costs for companies, and higher fuel consumption for customers. The integration of dual-engine hybrid technology can help to solve this problem. The objective of this study was to design and simulate a dual-engine hybrid electric vehicle (DE-HEV) model to investigate whether it can be a fuel efficient and environmentally friendly solution without sacrificing vehicle performance. The simulated DE-HEV uses two small engines instead of one large engine. In the simulated design, a smaller single engine supplies the power if the energy need is not more than a single engine can provide. The second engine turns on when the power demand is greater than the single engine can supply. Working models for the DE-HEV components, such as an electric motor, generator, battery, and the controller have been developed using the Matlab/Simulink™ simulation package. Each model was validated with test data from the literature. Appropriate power management strategy has been developed to accommodate the dual engine design. Fuel-efficiency, overall performance, and manufacturing cost for the simulated DE-HEV model have been compared against current commercial models. Simulation results showed that DE-HEV has between a 2% to 6% higher efficiency than comparable HEVs. Cost analysis results showed that the manufacturing cost of DE-HEV is 11% higher. Performance of the vehicle was tested with standard drive cycles. Test results are satisfactory; although there was significant increase in fuel-efficiency, because of its higher initial manufacturing cost, maintenance, and complexity, DE-HEVs may have challenges in the short term. However, with expected decreases in manufacturing costs of battery storage and power electronics technology, the implementation of DE-HEVs can be feasible transportation options in the near future

Design of the experimental setup for a plug-in hybrid electric vehicle

This paper identifies the procedure utilized to determine the required ratings of components for the experimental setup of a 2 by 2 power-split connected plug-in hybrid electric vehicle. The test vehicle considered for this project has been selected from the available small scale conventionally driven vehicles in Western Australia. The main criteria for vehicle selection required that an existing electrical network was available, with alternator and battery and that the chassis has significant space and supportable structure for the coupling of an electric motor to the driveshaft. Following the selection of the vehicle the appropriate sizing of electrical components was undertaken considering a scaled standardized drive cycle selected to be utilized for testing. This involves the estimation and selection of the electric motor size, energy storage requirement and associated ratings of power electronics for control. The ADVISOR software package has been utilized to support the calculated sizes of electrical components for this experimental setup

Trends and Hybridization Factor for Heavy-Duty Working Vehicles

Reducing the environmental impact of ground vehicles is one of the most important issues in modern society. Construction and agricultural vehicles contribute to pollution due to their huge power trains, which consume a large amount of petrol and produce many exhaust emissions. In this study, several recently proposed hybrid electric architectures of heavy-duty working vehicles are presented and described. Producers have recently shown considerable attention to similar research, which, however, are still at the initial stages of development. In addition, despite having some similarities with the automotive field, the working machine sector has technical features that require specific studies and the development of specific solutions. In this work, the advantages and disadvantages of hybrid electric solutions are pointed out, focusing on the greater electromechanical complexity of the machines and their components. A specific hybridization factor for working vehicles is introduced, taking into account both the driving and the loading requirements in order to classify and compare the different hybrid solutions

Development and Validation of a Control Strategy for a Parallel Hybrid (Diesel-Electric) Powertrain

The rise in overall powertrain complexity and the stringent performance requirements of a hybrid electric vehicle (HEV) have elevated the role of its powertrain control strategy to considerable importance. Iterative modeling and simulation form an integral part of the control strategy design process and industry engineers rely on proprietary ?legacy? models to rapidly develop and implement control strategies. However, others must initiate new algorithms and models in order to develop production-capable control systems. This thesis demonstrates the development and validation of a charge-sustaining control algorithm for a through-the-road (TTR) parallel hybrid (diesel-electric) powertrain. Some unique approaches used in powertrain-level control of other commercial and prototype vehicles have been adopted to incrementally develop this control strategy. The real-time performance of the control strategy has been analyzed through on-road and chassis dynamometer tests over several standard drive cycles. Substantial quantitative improvements in the overall HEV performance over the stock configuration, including better acceleration and fuel-economy have been achieved