Refine Your Search


Search Results

Viewing 1 to 11 of 11
Technical Paper

Reduced Order Modeling of Engine Transients for Gasoline Compression Ignition Combustion Control

This work focuses on reducing the computational effort of a 0-dimensional combustion model developed for compression ignition engines operating on gasoline-like fuels. As in-cylinder stratification significantly contributes to the ignition delay, which in turn substantially influences the entire gasoline compression ignition combustion process, previous modeling efforts relied on the results of a 1-dimensional spray model to estimate the in-cylinder fuel stratification. Insights obtained from the detailed spray model are leveraged within this approach and applied to a reduced order model describing the spray propagation. Using this computationally efficient combustion model showed a reduction in simulation time by three orders of magnitude for an entire engine cycle over the combustion model with the 1-dimensional spray model.
Technical Paper

Case Study of an Electric-Hydraulic Hybrid Propulsion System for a Heavy Duty Electric Vehicle

In order to improve efficiency and increase the operation of electric vehicles, assistive energy regeneration systems can be used. A hydraulic energy recovery system is modeled to be used as a regenerative system for supplementing energy storage for a pure electric articulated passenger bus. In this study a pump/motor machine is modeled to transform kinetic energy into hydraulic energy during braking, to move the hydraulic fluid from the low pressure reservoir to the hydraulic accumulator. The simulation of the proposed system was used to estimate battery savings. It was found that on average, approximately 39% of the battery charge can be saved when using a real bus driving cycle.
Technical Paper

Design, Control, and Power Management of a Battery/Ultra-Capacitor Hybrid System for Small Electric Vehicles

This paper introduces design, control, and power management of a battery/ ultra-capacitor hybrid system, utilized for small electric vehicles (EV). The batteries are designed and controlled to work as the main energy storage source of the vehicle, supplying average power to the load; and the ultra-capacitors are used to meet the peak power demands during transients. Power management system determines the directions of power flow, according to load demand. Presented analyses validate the efficient power management methodology.
Technical Paper

Research on On-line Monitoring Methods of High Voltage Parameter in Electric Vehicles

Safety control and protection strategy of high-voltage system of electric vehicles include analysis of circuit condition before connection to high voltage terminal, transient current prevention for capacitive load, real-time monitoring and analysis of high-voltage system during operation, disconnecting strategy of high voltage terminals, vehicle dynamic safety and cooperative management of electrical systems, etc. Monitoring and analysis of some critical parameters of high voltage system such as insulation, electrical harness and connector condition are the basis and difficulties in high-voltage safety and protection. This paper presents several mathematical models of monitoring critical parameters, and experiments were also done to evaluate the model. Disadvantages of the commonly used calculation method are discussed. Single point insulation defect model is introduced and diagnosis method of multiple points defect is also discussed.
Technical Paper

Constant Power Load Characteristics in Multi-Converter Automotive Power Electronic Intensive Systems

Intensifying demands for higher fuel economy from one hand and environmental concerns from the other are driving advanced automotive power systems to be more electric. As a result, automotive electrical systems with higher capacity and more complexity are needed to cope with this expanding electrification trend. As different electrical applications and loads are being introduced in automobiles, multi-converter intensive power electronic systems are emerging as the next generation of the advanced automotive electrical systems. In fact, power electronic converters and electric motor drives are inevitable parts of more electric automotive power systems. When power electronic converters and electric motor drives are tightly regulated to improve system performance and efficiency, they present negative impedance characteristics of constant power loads to the entire automotive electrical system. This destabilizing effect may cause system instability.
Technical Paper

Effects of an Ultra-Capacitor and Battery Energy Storage System in a Hybrid Electric Vehicle

This paper focuses on the effects of ultra-capacitors as a component of energy storage in hybrid electric vehicles (HEV). The main energy source in a hybrid vehicle is the battery. HEVs with battery sources are presently fairly effective; however, major drawbacks include the cost and size of such batteries. The purpose of this paper is to demonstrate that the addition of ultra-capacitors as a component of the energy storage system can reduce these drawbacks significantly by reducing the size of batteries required to drive the vehicle. To integrate ultra-capacitors into hybrid vehicles, the ADvanced VehIcle SimulatOR (ADVISOR) was used. The vehicle used to conduct this study was the 2004 Jeep Liberty sport utility vehicle (SUV). To simplify the analysis process, the conventional Jeep Liberty was modeled in ADVISOR to resemble the actual performance specifications of the SUV currently in the market.
Technical Paper

Automotive Interprofessional Projects (IPRO®) Program at Illinois Institute of Technology

The Illinois Institute of Technology (IIT) Interprofessional Projects (IPRO®) Program engages multidisciplinary teams of students in semester-long projects, with a total of thirty to thirty-five different projects offered every semester. This program greatly contributes to IIT's signature undergraduate education experience, with each interprofessional course delivering a team-oriented, project-based requirement within the undergraduate curriculum. Among its many benefits, each interprofessional course offers students the opportunity to integrate the education and research environment of the university to tackle real-world problems. In the process, students get the chance to develop and emerge from the experience with maturity, confidence, and valuable professional skills that are highly sought after in the workplace, simultaneously preparing them for the realities of today's global, highly-competitive environment [1].
Technical Paper

42V Integrated Starter/Alternator Systems

The increasing power demand in vehicles has resulted in a need for a higher onboard generation capacity. With the increasing generation requirement, the torque levels of the generator are found to closely converge with that of the starter motor. Hence, integrating the two machines and using a single machine for the two purposes would be technically viable and economically advantageous. This results in a more compact design solution as well. The Integrated Starter/Alternator (ISA) will be integrated directly to the crankshaft of the Internal Combustion Engine (ICE) and deliver 5 kW average and 12-15 kW peak power at 42V.
Technical Paper

Design and Implementation of a Mobile Single-Phase AC Power Supply for Land Vehicles with 28V/200V Dual Voltage Alternators

In land vehicles with high-power electrical loads, other than the low-voltage DC bus (14V, 28V, or 42V) for the low-power conventional loads, a high-voltage bus, e.g., 200V DC, is required for high-power loads such as hotel loads and electrically-assisted propulsion systems. In addition, some advanced electrical loads including luxury loads and AC power point require 120V, 60Hz AC voltage. These land vehicles include heavy duty, fire fighting, and military vehicles. There are two traditional approaches in obtaining a dual DC voltage bus system. The first one is to obtain the low-voltage DC from the alternator and boost it to the high-voltage DC. The second method is to obtain the high-voltage DC directly from the alternator and reduce it to the low-voltage. Both approaches require additional step-up or step-down power conversion stages, which inherently result in a reduced efficiency. In this paper, a new approach with a 28V/200V dual voltage alternator is considered.
Technical Paper

On the Suitability of a New High-Power Lithium Ion Battery for Hybrid Electric Vehicle Applications

Due to the low cost of the battery cells and excellent performance at ambient temperature, Lithium-ion (Li-ion) battery is a promising technology for propulsion applications. However, the performance of Li-ion batteries erodes drastically at extreme temperatures (above 65 °C or below 0 °C). Therefore, in order to maintain battery life and performance, it is crucial to keep the batteries within the temperature range where their operating characteristics are optimal. The need for expensive and complex thermal management systems has in fact kept the Li-ion technology from becoming the first choice for Hybrid Electric Vehicle (HEV) applications. In this paper, we propose a Phase Change Material (PCM) for the temperature control. Due to its high heat capacity, PCM absorbs the heat dissipated by the battery. As long as the heat emitted by the battery does not melt the PCM completely, the system is stable.
Technical Paper

A Modular Approach to Powertrain Modeling and Shift Quality Analysis

A library of macro modules has been written that represent elements common to powertrains of off-highway equipment with diesel powerplants and powershift transmissions. This library allows users to easily and quickly develop complex models of a wide range of vehicle and transmission configurations. These simulation models can be used to evaluate dynamic loadings on the powertrain components, evaluate shift quality, develop control systems and address other powertrain dynamic problems. The library makes use of EASY5 simulation language features to effectively handle such drivetrain nonlinearities as backlash, coulomb friction and hard stops.