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Lean Gasoline Direct Injection (LGDI) combustion is a promising technical path for achieving significant improvements in fuel efficiency while meeting future emissions requirements. Though Stoichiometric Gasoline Direct Injection (SGDI) technology is commercially available in a few vehicles on the American market, LGDI vehicles are not, but can be found in Europe. Oak Ridge National Laboratory (ORNL) obtained a European BMW 1-series fitted with a 2.0l LGDI engine. The vehicle was instrumented and commissioned on a chassis dynamometer. The engine and after-treatment performance and emissions were characterized over US drive cycles (Federal Test Procedure (FTP), the Highway Fuel Economy Test (HFET), and US06 Supplemental Federal Test Procedure (US06)) and steady state mappings. The vehicle micro hybrid features (engine stop-start and intelligent alternator) were benchmarked as well during the course of that study. The data was analyzed to quantify the benefits and drawbacks of the lean gasoline direct injection and micro hybrid technologies from a fuel economy and emissions perspectives with respect to the US market. Additionally that data will be formatted to develop, substantiate, and exercise vehicle simulations with conventional and advanced powertrains.

Electrical power requirements for vehicles continue to increase. Future vehicle applications require the development of reliable and robust power supply strategies that operate over various ambient temperatures and driving conditions. Insufficient charge balance is one of the major concerns for conventional lead-acid battery systems when operated with limited charging times during short journeys or extreme climate conditions. For vehicle power supply analysis, a detailed understanding of the operational characteristics of the major components and how they interact as a part of the electric power system, including environmental and road conditions, is essential if the analysis is to aid system optimization. This paper presents a model based technique that enhances the process of vehicle electrical power system design. Vehicle system optimization using virtual prototypes has become critically important as more electrical features are added to future vehicles. Real vehicle data has been used to validate the models performance against specific design acceptance criteria. The validation measurements have been performed for different battery and ambient temperature conditions in order to demonstrate the accurate prediction of the simulation and modeling approach. TRENDS IN AUTOMOTIVE INDUSTRY The power consumption of vehicle electrical systems has increased dramatically over the last 10 years. Increased comfort and convenience features, electrification of existing mechanical systems and improved safety are some of the main trends that contribute to such an electrical power increase on any vehicle model design [1, 2, 3]. The increase of electrical power consumption suggests the need to evaluate its impact upon fuel consumption, emissions and driving performance. This is because increased electrical power consumption invariably leads to larger power supply components that increase vehicle Trends in automotive technology •Reduced fuel emissions •Improved fuel economy •Increased comfort and convenience •Improved safety Such trends require also more electrical power and increased battery durability •Investigation of different power supply techniques •Development of optimisation simulation techniques •Focus on managing major electrical loads, cranking requirements, quiescent currents and over -discharge situations •Increased Durability of Lead acid Calcium (Flooded) •Improvement of Existing Development of PMS or BMS Technologies e.g. Alternators • Figure 1: Trends in Automotive Technology weight and the power drawn from the engine. Automotive manufacturers such as Jaguar and Land Rover, often develop power management techniques and integrate various electronic components (battery monitoring systems etc.) to accommodate the increase of vehicle electrical power consumption whilst minimizing any adverse effect upon the electrical components and the whole vehicle. The development of dynamic simulation models that are based upon vehicle electrical systems provides a basis for analyzing complicated systems and predicting their performance and behavior when operating under a variety of different conditions. Modeling and simulation of various electrical power system configurations, combined with the development of new techniques for the optimization and control of a vehicle power network, can provide a competitive advantage to a vehicle manufacturer. Reduced manufacturing costs in terms of reduced delivery time of the product, improved engineering processes during development are some of the advantages that can be obtained from the use of new simulation models and techniques. Figure 1 illustrates the most important trends that are currently driving the automotive industry: VEHICLE ELECTRICAL CHARGING SYSTEM AND ITS RELEVANT COMPONENTS ARCHITECTURE OF VEHICLE POWER NETS Present vehicle electrical charging systems are usually divided into three major parts (storage battery, alternator, and electrical features/loads). The starter as a component and its associate wiring harness have not been taken into account in this development since the subject of this study is focused on simulations intended to investigate the battery charge balance of a vehicle under different ambient temperature and driving conditions. Figure 2 shows a schematic diagram of a vehicle charging system and how each part may be modeled as an equivalent circuit. Choosing and calibrating charging system components very early in the development phase of a vehicle program will avoid reliability issues from undersizing components and may prevent over-sizing the components which affects the overall cost of the vehicle in addition to increasing its fuel consumption and, sometimes, exhaust emissions. The ultimate design of an optimum charging system, which is appropriate for most operational conditions, is usually obtained through extensive charge balance experimental tests.

Due to the introduction of new safety and comfort systems in modern automobiles, stability of the vehicle electrical system is increasingly important. The increasing number of electrical components demands that additional electrical energy be provided from robust, reliable supply sources in vehicles. When designing such systems, simulation is the development tool that is used to quickly obtain information regarding electrical system stability, battery charge level, and the distribution of power to the consumer systems. This paper describes how the Saber simulation environment from Synopsys Corporation helps develop increasingly demanding and complex vehicle power systems. A Volkswagen vehicle power net serves as an illustration. INTRODUCTION AND OBJECTIVES Automobiles do not have a constant energy supply nevertheless energy is required for starting the engine as well as for consumer systems that remain active when the engine is off. To supply this need, the battery serves as a storage device as well as a buffer. The battery has to deliver energy when there are peaks in the demand of consumption. These consumption peaks have increased by kilowatts in recent years, and this trend appears likely to continue into the foreseeable future. To increase battery life and optimally use existing resources, intelligent energy management (EM) algorithms are being introduced to ensure reliable, efficient energy and battery management. In addition, systems simulation is being turned to accelerate the development process since it provides a convenient way to quickly obtain information regarding electrical system stability, battery charge level, and the distribution of power to the consumer systems. Most importantly, simulation allows the performance of an automobile under different environmental conditions to be quickly and easily determined. Variations of ambient temperature, driving cycles or power consumption, and other dynamic factors can be easily simulated. However, the essential advantage of simulation is that it allows automobiles to be optimized at an early stage of development, before a prototype is produced. This advantage reduces time to market while delivering superior vehicles. Simulation also allows quick and easy development of energy management algorithms, as development is possible at a higher level of abstraction for the electronic control unit (ECU). Of course simulation models must be validated with conventional assessment methods, to help ensure that simulation results remain reliable. One application of simulation is energy balance simulation for quickly obtaining information about power net stability, battery charge level, and the distribution of power to conveniences for operator and passenger comfort without requiring a large amount of time for technical measurements. The following sections describe the necessary elements for designing a simulation model for automotive applications focussing on the analysis of overall electrical power consumption in the vehicle. Vehicle Equipment • Voltages • Currents • State of charge • Alternator utilization • EM validation Drive Cycle

Argonne National Laboratory (ANL) researchers have embarked on an ambitious program to quantitatively demonstrate the potential of hydrogen as a fuel for internal combustion engines (ICEs) in hybrid-electric vehicle applications. In this initiative, ANL researchers need to investigate different hybrid configurations, different levels of hybridization, and different control strategies to evaluate their impacts on the potential of hydrogen ICEs in a hybrid system. Because of limitations in the choice of motor and battery hardware, a common practice is to fix the size of the battery and motor, depending on the hybrid configuration (starter/alternator, mild hybrid, or full hybrid) and to tune the system control for the above-available electrical power/ energy. ANL has developed a unique, flexible, Hardware-In-the-Loop (HIL) platform for advanced powertrain technology evaluation: The Mobile Advanced Technology Testbed (MATT). MATT has the flexibility to easily test advanced components in various hybrid configurations. In addition, MATT has the capability of emulating any size of motor and battery. Therefore, the powertrain under test can be evaluated with different levels of hybridization. The versatile control system software developed by ANL provides rapid evaluation of control options associated with each hybrid configuration and each level of hybridization. The powertrain currently under investigation at ANL consists of a supercharged hydrogen-fueled internal combustion engine and a dual clutch transmission. The engine and transmission are not emulated and are therefore fixed in terms of sizing. Since the motor and the battery are emulated, MATT makes it possible to resize the battery and the motor for every change in control strategy, thus enabling an iterative loop between control strategy and component sizing. This iterative sizing process would then result in components optimized for a control strategy. The ultimate aim of this iterative process is to identify the optimal control strategy and component sizing for a particular specifications set (performance and fuel economy). As a first step, this interdependent sizing process was studied in simulation only by using ANL-developed PSAT (Power-train System Analysis Toolkit) [1], and the results are presented in this paper. The next stage is to validate the simulation results with the test data collected on MATT for different levels of hybridization and different control strategies.

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. This system avoids the additional power conversion stage and, as a result, increases the efficiency of the system. The primary objective of this paper is to demonstrate the design and operation of a high power density, 2.5 kW, single-phase, DC/AC pulse width modulated (PWM) inverter. The IGBT-based inverter operates from the 200V DC voltage output of the dual voltage alternator and consists of a low-pass LC filter at its output. The RMS value of the AC output voltage attained from the mobile power supply is 120V at a frequency of 60Hz. The sinusoidal pulse width modulation (SPWM) method is used as the control technique for the purpose of inverter switching. These PWM control signals are generated using a digital signal processor (DSP) and are eventually used to drive the gates of the IGBT switches of the proposed inverter. Due to the simplified power stage and the usage of an efficient DSP-based modulation technique, the total harmonic distortion (THD) of the output voltage is fairly low (less than 2%) and a relatively small overall inverter size is achieved. A detailed description of the system along with simulation and experimental results are presented in this paper.

This paper investigates the use of an adaptive proportional-integral-derivative (APID) controller to reduce a combustion engine crankshaft speed pulsation. Both computer simulations and engine test rig experiments are used to validate the proposed control scheme. The starter/alternator (S/A) is used as the actuator for engine speed control. The S/A is an induction machine. It produces a supplemental torque source to cancel out the fast engine torque variation. This machine is placed on the engine crankshaft. The impact of the slowly varying changes in engine operating conditions is accounted for by adjusting the APID controller parameters on-line.

Inverters are solid state devices which change DC to 120VAC electricity. They are sufficiently rugged and reliable to make them practical for use on utility vehicles for operating thumpers, tools, lights and induction motor loads. The SCR type rather than the transistor type inverter is generally required for inductive and reactive loads. Static inverters operate from battery input. They provide power without running an engine, but are limited by battery capacity so they work best in intermittent load applications. Dynamic inverters operate from alternator input and will handle continuous loads to 7200 watts with truck engine running.

Following the successful testing of the 25 kWe Space Power Demonstrator (SPD) engine in 1985, a Stirling Space Engine (SSE) technology advancement program was initiated. The program`s objective was to advance free-piston Stirling engine/alternator technology sufficiently so that a Stirling engine system may become a viable candidate for space power applications. Evolution of the SSE technology is planned to occur at three different engine heater temperature levels: 650, 1050, and 1300 K. These temperatures define three phases of technology development with the first phase involving the 650 K SPD engine. Technology development of the 650 K engine and preliminary design of the 1050 K engine will be discussed in this paper.