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Technical Paper
2014-09-30
Ilya A. Kulikov, Elena E. Baulina, Andrey I. Filonov
The paper gives a short description of the University’s developments in the field of hybrid electric powertrains and vehicles, and a survey of theoretical instruments utilized in these developments regarding powertrains control strategies. For the moment, two units fitted with hybrid powertrains are in operation. These are the four-wheel-drive SUV and the powertrain test rig. Both allow to test different powertrain configurations. Prior to implementing a certain configuration in the rig, an extensive theoretical research of powertrain is conducted to reveal its properties and find a way to control it optimally. The basic tool adopted for that purpose is R. Bellman’s dynamic programming (DP). The paper gives an example of applying DP to explore a potential of decreasing fuel consumption and pollutant emissions of van-type vehicle by converting its powertrain into hybrid one. During this study, a contradiction has emerged between minimizing fuel consumption and emissions of NOx. An example shows the way to resolve this contradiction by tuning the cost function.
Technical Paper
2014-09-30
Daofei Li, Huanxiang Xu, Lei Wang, Zhipeng Fan, Wenbo Dou, Xiaoli Yu
Internal combustion engine is expected to be the major power unit to propel vehicles for decades from now on. Therefore, the advanced technologies to improve energy efficiency and to reduce emissions of engine should be continually encouraged and emphasized. For normal driving conditions, nearly half energy of the consumed fuel of engine is wasted, in the form of exhaust heat and coolant heat. In order to recovery the waste heat generated in normal thermodynamic cycle of internal combustion engine, a novel hybrid pneumatic engine concept is proposed, which uses compressed air and fuel as dual energy. During the expansion stroke, additional compressed air is injected, with carefully optimized timing, into the cylinder to absorb the heat released by the fuel, and then the compressed air can do further expansion work. The ideal thermodynamic model of the hybrid pneumatic engine cycle is established and explored, and is used to analyze the influences of the main design parameters on the cycle performance.
Technical Paper
2014-09-30
Christopher Atkinson
Pending GHG emissions reduction legislation for medium and heavy duty vehicles will require the development of engines and powertrains with significantly increased mechanical and electronic complexity. Increasing powertrain efficiency will require the simulation, control and calibration of an expanding number of highly interdependent air, fuel, exhaust, combustion and energy transfer subsystems. As a result, engine and powertrain control is becoming significantly more sophisticated to develop and difficult to optimize. The high cost of developing engines and powertrain systems that demonstrate greater fuel efficiency and emissions benefits than the engines of today, is undeniable. The increased calibration burden and the complexity of optimization require the development and adoption of entirely new methods for transient engine calibration and optimization to achieve maximum vehicle fuel efficiency and lowest regulated emissions. Model-based rapid transient calibration offers significant advantages over traditional testing-intensive methods of calibration.
Technical Paper
2014-09-30
Jennifer Wheeler, Joshua Stein, Gary Hunter
Recent advances in natural gas recovery technologies and availability have sparked a renewed interest in using natural gas as a fuel for commercial vehicles. Natural gas can potentially provide for both reduced operating cost and reductions in CO2 emissions. Commercial natural gas vehicles, depending on application and region, will have different performance and fuel consumption targets and are subject to various emissions regulations. Therefore, different applications may require different combustion strategies to achieve specific targets and regulations. This paper summarizes an evaluation of combustion strategies and parameters available to meet these requirements while using natural gas. One combustion strategy that was evaluated was stoichiometric combustion with exhaust gas recirculation (EGR), while the other strategy tested was based on lean-burn combustion. Testing consisted of parametric variations to quantify the effects of swirl ratio, compression ratio, and dilution ratio, either via EGR or excess air, on the operating limits, engine out emissions, and fuel efficiency of spark-ignited natural engines operating in conditions typical for heavy-duty vehicle applications.
Technical Paper
2014-09-30
Yang Li, JianWei Zhang, Konghui Guo, Dongmei wu
It is also very important to save energy and improve the energy efficiency of the electric vehicle. For the 4WD electric vehicle with PMSM hub motors, the motor drive system is the main energy transmission link. If the efficiency of the motor drive system can be improved, the energy efficiency of the vehicle can also be enhanced, the better performance of motors can be gained and the thermal condition of each hub motor can be improved. As a result, it is very significant to study the torque distribution algorithm between front and rear hub motors in 4WD electric vehicle systems with independently driven wheels to improve the energy efficiency of the vehicle. This paper presents an optimized torque distribution algorithm based on the loss model of multi-motors drive system for the 4WD electric vehicle with PMSM hub motors, which operate at straight line condition. The main content include: develop a comparative accurate mathematical model of permanent magnet synchronous in-wheel motor considering the iron loss and gain the loss model of single motor, which include copper loss, iron loss and mechanical loss ; when the electric vehicle operates at straight line condition, realize the loss model of front and rear motors, which operate at the same speed and torque condition; realize the on-line identification of motor parameters based on the MARS, which is important for updating the efficiency model of the motor drive system when the motor parameters are changing; realize the optimized torque distribution algorithm based on the loss model of the multi-motors drive system to improve the energy efficiency.
Technical Paper
2014-09-30
Yang Li, JianWei Zhang, Konghui Guo, Dongmei wu
The driving and braking torque distribution method between front and rear axles for the four-wheel-drive electric vehicles is comparative flexible, and the reasonable distribution method is very significant for improving the vehicle dynamics stability and the energy efficiency. This paper presents from the perspective of improving the vehicle dynamics stability, without regard to the energy efficiency and optimization for the present. In the paper the target of the ideal driving and braking torque distribution, which is gained according to the friction circle of tyre force, is to make the front and rear axles reach at the adhesion limit at the same time when the vehicles operate at various conditions. At first, gain the ideal driving and braking torque distribution when the electric vehicles operate at straight motion condition and the lateral acceleration is zero. Secondly, the ideal driving and braking torque distribution is expanded into the various conditions with the lateral stability demand, which can enhance the limit of lateral stability of the vehicle performance.
Technical Paper
2014-09-30
Philipp Scherer, Marcus Geimer
It was investigated how the energy efficiency of heavy equipment can be determined and evaluated. The wide range of applicability of heavy equipment, as well as the existence of one or more power take-offs require, a special approach for evaluating the energy efficiency of these machines. Therefore, different types of heavy equipment vehicles were equipped with sensors and measurement instrumentation throughout the whole powertrain. With these vehicles, field tests were realised in order to receive perception about the life cycles and the exact kinematic paths of these vehicles as well as to observe the power- and energy flows throughout the powertrain. Parameters were varied in order to receive information about the impact of environmental effects on the energetic- and temporal shares of the kinematic paths. For the analyzation of these measurements a software package has been developed. This package provides features to analyze the kinematic paths of the performed field tests. Furthermore it is possible to show the energy flows within the powertrain for selected time periods.
Technical Paper
2014-09-30
Harry Dwyer, Seungju Yoon, David Quiros, Mark Burnitzki, Roelof Riemersma, Donald Chernich, John Collins, Jorn Herner
A novel ambient dilution wind tunnel has been designed, tested and used to measure the emissions from “Active Parked Regenerations” of Diesel Particulate Filters (DPFs) for 2007 and 2010 certified heavy duty diesel trucks (HDDTs). The HDDT exhaust was routed to the wind tunnel entrance, and a mixing plate was employed to induce rapid mixing with the ambient air inflow. The tunnel geometry consisted of a 4’ by 4’ cross-section, and the tunnel length was 30’. An induction fan created a flow of 9000 ft3/min (CFM), and velocity and temperature traverses indicated that the mixture of exhaust gases and ambient air was homogeneous at the emission sampling location. The sampling probe was located near the exit of the tunnel, and withdrew 6 CFM from the tunnel centerline for PM measurements. A wide variety of emissions measurements and instrumentation was used in the investigation, which included the following: (1) Engine out On-board diagnostics; (2) Exhaust flow PEMS; (3) Tunnel temperature, CO2, mixture dilution ratio, and relative humidity; (4) Real-time PM instrumentation: EEPS, SMPS, DustTrak, and Dekati Mass Monitor; and (5) Gravimetric filter media.
Technical Paper
2014-09-30
Massimiliano Ruggeri, Carlo Ferraresi, Luca Dariz, Giorgio Malaguti
Abstract Functional safety requirements and solutions are more expensive when it comes to lower cost machines with less power but same functionalities with respect to big machines. The paper will show a real Electronic Control Unit (ECU) design of a machine controller, controlling both engine working point, transmission, and other utilities like PTO, 4WD, brakes and Differential Lock; the ECU was designed in accordance to ISO 25119 regulation, to meet AgPL = C or even D for some functionalities. The unit is a fully redundant electronic control unit with two CAN networks and some special safe state oriented mechanism, that allow the Performance Level C with less software analysis requirements compared with traditional solutions. All safety critical sensors are redounded and singularly diagnosable, all command effects are directly observable and most of commands are directly diagnosable. With a minimum extra-cost the hardware category for the most critical controls was brought to the category 4, thus theoretically allowing the Performance Level D achievement.
Technical Paper
2014-09-30
Hanlong Yang
Adaptive estimation approach for air-path controls in Turbocharged Diesel Engines Due to more stringent emission regulations as well as the customer requirements on performance improvement, the model-based controls in diesel engines are becoming more and more common and necessary. In fact, as diesel engine systems become more complicated with additional hardware, such as throttle, EGR, VVT, VGT, the dynamics of the systems with more freedom of multiple actuators become much more sophisticated. The advanced model-based and coordinated controls become almost the only effective way to improve the system performance. In most of the model based approaches, feedback controls and estimation methods based on real-time dynamics are the key techniques. However since the system has sensors and actuators which have parts-to-parts variations as well as degradation over useful life, therefore any identification of those slow changes and compensation of the controls over the system life cycle is critical for long term control performance, system reliability and diagnostic monitoring.
Technical Paper
2014-09-16
Jon Zumberge, John Mersch
Cost and performance requirements are driving military and commercial systems to highly integrated, optimized systems which require more sophisticated, highly complex controls. To realize benefits and make confident decisions, the validation of both plant and control models becomes critical. To quickly develop controls for these systems, it is beneficial to develop models and determine the uncertainty of those models so as to predict performance and stability. A process of model validation for a boost circuit based on acceptance sampling is presented here. The validation process described in this paper includes the steps of defining requirements, performing a screening and exploration of the system, completing a system and parameter identification, and finally executing a validation test. To minimize the cost of experimentation and simulation, design of experiments is used extensively to limit the amount of data taken without losing information. One key contribution in this paper is the use of tolerance intervals as an estimation of model accuracy.
Technical Paper
2014-09-16
Shweta Sanjeev, Goutham Selvaraj, Patrick Franks, Kaushik Rajashekara
Abstract The transition towards More Electric Aircraft (MEA) architectures has challenges relating to integration of power electronics with the starter generator system for on-engine application. To efficiently operate the power electronics in the hostile engine environment at high switching frequency and for better thermal management, use of silicon carbide (SiC) power devices for a bi-directional power converter is examined. In this paper, development of a 50 kVA bi-directional converter operating at an ambient temperature of about 2000C is presented. The design and operation of the converter with details of control algorithm implementation and cooling chamber design are also discussed.
Technical Paper
2014-09-16
Fei Gao, Serhiy Bozhko, Greg Asher
Abstract Stability is a great concern for the Electrical Power System (EPS) in the More Electric Aircraft (MEA). It is known that tightly controlled power electronic converters and motor drives may behave as constant power loads (CPLs) which may produce oscillations and cause instability. The paper investigates the stability boundaries for dc multi-source EPS under different power sharing strategies. For each possible strategy the corresponding reduced-order models are derived. The impedance criterion is then applied to study the EPS stability margins and investigates how these margins are influenced by different parameters, such as main bus capacitance, generator/converter control dynamics, cabling arrangements etc. These results are also illustrated by the root contours of reduced-order EPS models. Theoretical results achieved in the paper are confirmed by the time-domain simulations.
Technical Paper
2014-09-16
Brian C. Raczkowski, Benjamin Loop, Jason Wells, Eric Walters, Oleg Wasynczuk, Sean Field, Jason Gousy
Abstract Future more electric aircraft (MEA) architectures that improve electrical power system's (EPS's) source and load utilization will require advance stability analysis capabilities. Systems are becoming more complex with bidirectional flows from power regeneration, multiple sources per channel and higher peak to average power ratios. Unknown load profiles with large transients complicate common stability analysis techniques. Advancements in analysis are critical for providing useful feedback to the system integrator and designers of multi-source, multi-load power systems. Overall, a framework for evaluating stability with large displacement events has been developed. Within this framework, voltage transient bounds are obtained by identifying the worst case load profile. The results can be used by system designers or integrators to provide specifications or limits to suppliers. Subsystem suppliers can test and evaluate their design prior to integration and hardware development. By identifying concerns during the design phase, a more streamlined approach to hardware development can save on rework, integration delays and cost.
Technical Paper
2014-09-16
Michael L. Zierolf, Thomas Brinson, Andrew Fleming
Abstract Recent emphasis on optimization of engine technologies with ancillary subsystems such as power and thermal management has created a need for integrated system modeling. These systems are coupled such that federated design methods may not lead to the most synergetic solution. Obtaining an optimal design is often contingent on developing an integrated model. Integrated models, however, can involve combining complex simulation platforms into a single system of systems, which can present many challenges. Model organization and configuration control become increasingly important when orchestrating various models into a single simulation. Additionally, it is important to understand such details as the interface between models and signal routing to ensure the integrated behavior is not contaminated or biased. This paper will present some key learnings for model integration to help alleviate some of the challenges with system-based modeling.
Technical Paper
2014-09-16
Jennifer C. Shaw, Patrick Norman, Stuart Galloway, Graeme Burt
Abstract Radical new electrically propelled aircraft are being considered to meet strict future performance goals. One concept design proposed is a Turboelectric Distributed Propulsion (TeDP) aircraft that utilises a number of electrically driven propulsors. Such concepts place a new and significant reliance on an aircraft's electrical system for safe and efficient flight. Accordingly, in addition to providing certainty that supply reliability targets are being met, a contingency analysis, evaluating the probability of component failure within the electrical network and the impact of that failure upon the available thrust must also be undertaken for architecture designs. Solutions that meet specified thrust requirements at a minimum associated weight are desired as these will likely achieve the greatest performance against the proposed emissions targets. This paper presents a Fault Tree Analysis (FTA) based design approach for the electrical system and thrust reliability analysis of TeDP aircraft architectures.
Technical Paper
2014-09-16
Serhiy Bozhko, Seang Shen Yeoh, Fei Gao, Tao Yang, Christopher Hill
Abstract The paper reports the control design for an aircraft electric starter-generator system based-on high-speed permanent magnet machine operated in a flux-weakening mode and controlled by an active front-end rectifier. The proposed system utilizes advances of modern power electronics allowing the use of novel machine types and the introduction of controlled power electronics into the main path of energy flow. The paper focuses on control design for such system and includes development of flux weakening control of high-speed permanent magnet machine and droop control of the system output dc-link current. The achieved analytical design results and the expected system performance are confirmed by time-domain simulations.
Technical Paper
2014-09-16
Christine Ross, Michael Armstrong, Mark Blackwelder, Catherine Jones, Patrick Norman, Steven Fletcher
Abstract The Turboelectric Distributed Propulsion (TeDP) concept uses gas turbine engines as prime movers for generators whose electrical power is used to drive motors and propulsors. For this NASA N3-X study, the motors, generators, and DC transmission lines are superconducting, and the power electronics and circuit breakers are cryogenic to maximize efficiency and increase power density of all associated components. Some of the protection challenges of a superconducting DC network are discussed such as low natural damping, superconducting and quenched states, and fast fault response time. For a given TeDP electrical system architecture with fixed power ratings, solid-state circuit breakers combined with superconducting fault-current limiters are examined with current-source control to limit and interrupt the fault current. To estimate the protection system weight and losses, scalable models of cryogenic bidirectional current-source converters, cryogenic bidirectional IGBT solid-state circuit breakers (CBs), and resistive-type superconducting fault current limiters (SFCLs) are developed to assess how the weight and losses of these components vary as a function of nominal voltage and current and fault current ratings.
Technical Paper
2014-09-16
Arthur V. Radun
Abstract There is a continuing need to simulate power electronic circuits that include magnetic components. It is necessary to determine the interaction of the magnetic component with the rest of the power electronic system so that a dynamic circuit model of the magnetic components including material saturation and iron losses is required. Also, the magnetic component model must be valid when the magnetic component's excitation is not sinusoidal. A dynamic magnetic circuit model derived from Maxwell's equations along with useful theorems for building circuit models from the structure of the magnetic device is reviewed. The developed circuit models are general including magnetic saturation and iron losses. Simulation results for a DC/DC converter employing a conventional gapped inductor and a gapped coupled inductor are presented.
Technical Paper
2014-09-16
Christopher Ian Hill, Chris Gerada, Paolo Giangrande, Serhiy Bozhko
Abstract This paper presents the initial development of a Modelica Library for Electro-Mechanical Actuator system analysis. At present two main system components are described, these are the Power Electronic Converter and Electric Machine, although further components will be added. These models provide the user with the ability to simulate Electric Machine and Power Electronic Converter systems including physical effects, losses and fault conditions. Established modelling programs such as Saber and MATLAB SimPowerSytems are often unable to provide all the aspects required to accurately simulate real systems in an easy to use, flexible manner. Therefore this paper shows how Modelica has been used to create versatile models able to simulate many practical aspects such as Power Electronic Converter losses and Power Electronic Converter faults, Electric Machine losses and Electric Machine faults. Examples are included in order to demonstrate the use of these models within a variety of systems including an Electro-Mechanical Actuator.
Technical Paper
2014-09-16
Neno Novakovic
Abstract Since the early 1970s, when microprocessors became commercially available, they quickly became a common part of all aircraft control and indication systems. With an ever-increasing number of microprocessor-based airborne applications, safety regulations and software standards like RTCA DO-178 evolved, demanding rigorous requirements and processes for software development, testing, life cycle, and certification. Over the years, as development of aerospace software applications increased, engineering costs of development and product certification costs exponentially increased, having a significant impact on the market. Landing Gear Actuation system is one of many aircraft systems whose control functions are based on microprocessors and software application. Considering that Landing Gear Actuation control algorithm can be defined in a form of the State Machine, this article intends to demonstrate that such controller can be realized as wired logic hardware, without software implementation.
Technical Paper
2014-09-16
Niloofar Rashidi Mehrabadi, Bo Wen, Rolando Burgos, Dushan Boroyevich, Chris Roy
Abstract The development of the concepts, terminology and methodology of verification and validation is based on practical issues, not the philosophy of science. Different communities have tried to improve the existing terminology to one which is more comprehensible in their own field of study. All definitions follow the same concept, but they have been defined in a way to be most applicable to a specific field of study. This paper proposes the Verification, Validation, and Uncertainty Quantification (VV&UQ) framework applicable to power electronic systems. Although the steps are similar to the VV&UQ frameworks' steps from other societies, this framework is more efficient as a result of the new arrangement of the steps which makes this procedure more comprehensible. This new arrangement gives this procedure the capability of improving the model in the most efficient way. Since the main goal of the VV&UQ process is to quantitatively assess the confidence in modeling and simulation, the second part of this paper focuses on uncertainty quantification.
Technical Paper
2014-09-16
Ralf Cremer, Alfred Engler
Abstract The application of power electronics in aircraft is increasing in the latest aircraft developments. This contribution focuses on the recent advances of activities at Liebherr-Elektronik GmbH linked to power electronics: active power filter based on fast silicon carbide switches, open box design for unpressurized area, light weight housing, EMC management, partial discharge detection and mitigation, arc-fault detection and standardized innovative power cores with optimized sensors. These topics are derived from a roadmap based on beforehand identified key drivers. These key drivers will enable the future More Electric Aircraft (MEA) by focusing on weight, reliability and cost. New technologies as Silicon Carbide (SiC) and advanced integration will support this strategy.
Technical Paper
2014-09-16
Noriko Morioka, Hidefumi Saito, Norio Takahashi, Manabu Seta, Hitoshi Oyori
Abstract Electrical power management is a key technology in the AEA (All-Electric Aircraft) system, which manages the supply and demand of the electrical power in the entire aircraft system. However, the AEA system requires more than electrical power management alone. Adequate thermal management is also required, because the heat generated by aircraft systems and components increases with progressive system electrification, despite limited heat-sink capability in the aircraft. Since heat dissipation from power electronics such as electric motors, motor controllers and rectifiers, which are widely introduced into the AEA, becomes a key issue, an efficient cooling system architecture should be considered along with the AEA system concept. The more-electric architecture for the aircraft has been developed; mainly targeting reduced fuel burn and CO2 emissions from the aircraft, as well as leveraging ease of maintenance with electric/electronic components. The AEA should pursue more efficient and eco-friendlier systems, which are easier to maintain than those of conventional aircraft/MEA (More-Electric Aircraft), to enhance benefits for passengers and operators.
Standard
2014-09-09
This SAE Standard covers dimensions, performance parameters and nomenclature of a push-pull control cable used in inboard marine throttle and shift applications.
Standard
2014-08-21
This SAE Recommended Practice provides minimum requirements and performance criteria for devices to prevent runaway snowmobiles due to malfunction of the speed control system.
WIP Standard
2014-08-18
This SAE Standard is intended to be used as a guide for manufacturers and users of general purpose industrial machines to provide a reasonable degree of protection for personnel during normal operation and servicing. This document excludes skid steers which are covered by SAE J1388. Avoidance of accidents also depends upon the care exercised by such persons (see SAE J153). Inclusion of this standard instate, federal, or any laws or regulations where flexibility of revision is lacking is discouraged.
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