Increasing demands for lower environmental impact from vehicles, including heavy-duty vehicles, have driven several vehicle manufacturers to consider adding hybrid electrical vehicles (HEV’s) to the product portfolio. Present research on batteries for HEV’s is mainly focused on lithium-ion battery chemistries, since lithium-ion batteries has the most promising technical potential compared to other types of batteries. However, the uncertainty regarding battery lifetime combined with a high battery cost can have a negative impact on large scale commercialisation of heavy-duty hybrid vehicles in the near future. A large part of present lithium-ion battery research is focused on new materials, but there is also research focusing on ageing of already established lithium-ion battery chemistries. Cycle ageing of batteries often includes complete charging and discharging of batteries or the use of standardized test cycles. Battery cycling in real HEV applications is however quite different compared to this kind of laboratory testing, and real life testing on vehicles is a way of verifying the soundness of laboratory ageing. The aim of this study was to develop a test method suitable for real life testing of lithium-ion batteries for heavy-duty HEV-usage, with the purpose of investigating the correlation of battery ageing and usage in real life applications. This concept study includes both cell level battery cycling and performance testing on board vehicles. The performance tests consist of discharge capacity measurements and hybrid pulse power characterization (HPPC) tests. The main feature of this test equipment is that it is designed to be used on conventional vehicles, emulating an HEV environment for the tested battery. The functionality of the equipment was verified on a heavy-duty HEV with satisfying results. Results from real life testing of 8 batteries using the developed test equipment on four conventional heavy-duty trucks shows that the concept of comparing battery ageing with battery usage has a most promising potential to be used as a tool when optimizing battery usage vs. lifetime. Initial results from this real life study shows significant differences in state of charge (SOC) and power distributions between cycled batteries, but so far only small differences in ageing. Lithium-ion batteries of the type lithium manganese spinel/lithium titanate (LMO/LTO) were used in this study. / Ökande krav på minskad miljöpåverkan från fordon, inklusive tunga fordon, har drivit flera fordonstillverkare till att addera hybridiserade fordon till produktportföljen. Forskning på hybridfordonsbatterier är idag huvudsakligen inriktad på litiumjonbatterikemier, vilken har den mest lovande tekniska potentialen jämfört med andra typer av batterikemier. Det finns idag en risk att osäkerheten kring litiumjonbatteriers livslängd i kombination med en hög batterikostnad kan ha en negativ inverkan på en storskalig kommersialisering av tunga hybridfordon inom den närmsta framtiden. En stor del av batteriforskningen är inriktad på nya material, men det finns även forskning som fokuserar på åldring av redan etablerade litiumjonbatterikemier. Vid åldringsprov används ofta standardiserade testcykler eller cykler där batterierna blir fullständigt laddade och urladdade. Cykling av batterier i verkliga förhållanden skiljer sig dock från den typen av laboratorietester och provning på fordon är därför ett sätt att kontrollera att laboratorieprovning ger relevanta resultat gällande åldring. Syftet med denna studie var att utveckla en testmetodik lämplig för provning av litiumjonbatterier för tunga hybridfordon i verklig drift, med syfte att undersöka kopplingen mellan batteriers åldrande och hur det används. Detta koncept inkluderar battericykling på cellnivå och möjligheten att utföra batteriprestandatester på fordon, där prestandatesterna består av kapacitetsprov och pulsprov. Den viktigaste egenskapen hos den utvecklade testmetodiken är att provning sker på konventionella fordon genom att emulera en hybridmiljö för det testade batteriet. Funktionaliteten hos den utvecklade testutrustningen verifierades på en tung hybridlastbil med goda resultat. Resultaten från en fältstudie av 8 batterier på 4 lastbilar där den utvecklade testutrustningen användes påvisar att testmetodiken har en lovande potential att kunna användas som ett verktyg vid optimering av utnyttjandegrad och livslängd för HEV-batterier. De initiala resultaten från denna fältstudie påvisar skillnader i laddningsgradsfördelning och batterieffektfördelning mellan cyklade batterier, men ännu bara små skillnader i åldring. Litiumjonbatterier av typen litiummanganspinel/litiumtitanat (LMO/LTO) användes i denna studie. / QC 20111205

No description available.

This master thesis project aims to complete and verify core functions of a test rig that is designed and built to emulate drive cycles for measuring the energy consumption of HEVs, especially a vehicle named ELBA from KTH Integrated Transport Research Lab (ITRL). To fulfill this goal, a simplified model is created for the test rig, whose involved parameters are identified through various experiments. Then the model is verified by both step voltage responses and sinusoidal current responses. Meanwhile, vehicle dynamics is modeled to calculate required resistance force for road slope emulation. Moreover, an existing method, vehicle equivalent mass, is utilized to compensate dynamic force of the vehicle body, enabling simulation of regenerative braking without an extra flywheel. Together with test rig’s model that is responsible for converting required resistance force to demanded current reference, the rig’s functions are completed and ready for final verification. As a result, the driver of the DC motor on the rig is found to has lower current limitation than required so that the rig is not able to entirely compensate dynamic force of the car. However, the feasibility of the principle is still proved by the tests. Based on the result, recommendations are given to solve the problem and achieve other improvements in the future. / Detta examensarbete syftar till att slutföra och verifiera kärnfunktioner i en testrigg som är designad och byggd för att emulera körcykler för att mäta energiförbrukningen för elhybridbilar, särskilt ett fordon som heter ELBA från KTH Integrated Transport Research Lab (ITRL). För att uppfylla detta mål skapades en förenklad modell för testriggen, vars parametrar identifieras genom olika experiment. Sedan verifieras modellen av både stegspänningssvar och sinusformade strömsvar. Under tiden modelleras fordonsdynamiken för att beräkna erforderlig motståndskraft för väglöpemulering. Samtidigt modelleras fordonsdynamiken för att beräkna den erforderliga motståndskraften för emulering av väglutningar. Dessutom används en befintlig metod, fordonsekvivalentmassa, för att kompensera fordonskroppens dynamiska kraft, vilket möjliggör simulering av regenerativ bromsning utan extra svänghjul. Tillsammans med testriggens modell som är ansvarig för att konvertera erforderlig motståndskraft till efterfrågad strömreferens, är riggens funktioner färdig och redo för slutlig verifiering. Som ett resultat har föraren av likström motorn på riggen visat sig ha lägre strömbegränsning än vad som krävs så att riggen inte helt kan kompensera bilens dynamiska kraft. Emellertid bevisas principens genomförbarhet fortfarande av testerna. Baserat på resultatet ges rekommendationer för att lösa problemet och uppnå andra förbättringar i framtiden.

No description available.

With gas prices on the rise, the demand for high-mileage and low pollution vehicles has taken on an unprecedented role in our society. The production and implementation of electric and hybrid-electric vehicles has recently been a large focus of all major automobile manufacturers. Although these new vehicles have begun to solve much of the expensive fuel consumption and air pollution problems that our economy faces, the initial cost of these vehicles has proven to still be too expensive to capture a significant portion of the market. The further advancement of this technology must not only continue to focus on better fuel efficient and decreased pollution producing vehicles, but also decrease the cost of these vehicles to make them more available and enticing to the general public. Results from this research include one potential solution to reduce the cost of electric and hybrid-electric vehicles. Previous research performed in this area has led to the investigation and bench-top testing of a special type of mechanical system known as a Planetary Differential (PD). An exploration of the functionality of this system has shown that the PD can simplify expensive and complex electronic control systems for electric and hybrid-electric vehicles, thus reducing the cost to the consumer. In this study, fundamental speed, torque and power relationships for the PD were developed and tested under various loading conditions. Advantages and disadvantages of the PD, as compared to other similar mechanical systems, are identified and outlined. Recommendations for future work and implementation of the PD in electric and/or hybrid-electric vehicles are presented herein.

No description available.

<p dir="ltr">Engine downsizing with the assistance of turbomachinery and/or energy storage system has been realized to be one of the most promising and cost-effective solutions in pursuit of cleaner and more efficient engine products. Fundamental challenges however, exist in terms of control and energy management of advanced powertrain featuring turbocharged engines due to their complex dynamics, inherent coupling nature, and strict emission regulations concerning environmental preservation. For the purpose of addressing those challenges, this dissertation develops an integrated framework for modeling, robust coordinated control, and power management of advanced powertrains featuring turbocharged engines.</p><p dir="ltr">This dissertation first studies an advanced turbocharged lean-burn SI natural gas engine manufactured by Caterpillar, and develops an intuitive physics-based, control-oriented model. The obtained control-oriented model is validated against a high-fidelity truth-reference model and serves as the basis on which a robust coordinated control system is developed. The dissertation then proposes a comprehensive procedure for synthesizing a robust coordinated control system applying optimization-based H_infinity control theory. Specifically, this framework outlines a methodology of modeling uncertainties to account for system robustness, and providing valuable insights into the tuning of general coordinated control system design. For performance testing, the synthesized robust coordinated control system is implemented on the high-fidelity truth-reference model. A parallel closed-loop simulation strategy is adopted so that direct comparison between the robust coordinated control system and benchmark production control system (composed of multiple fine-tuned PID controllers) developed by Caterpillar can be carried out. Simulation results manage to demonstrate the merit of utilizing the robust coordinated control system, with better performances observed in terms of steady-state tracking, transient response, and disturbance attenuation.</p><p dir="ltr">The second part of this dissertation focuses on the development of a proposed novel hybrid electric wheel loader which features a downsized engine assisted by turbocharger and an energy storage system. Research efforts documented in this dissertation involve system configuration, controller design (both component-level and supervisory-level), simulation development (both software-in-the-loop and hardware-in-the-loop) and simulated validation for the proposed novel wheel loader. Inspired by the successful simulation results, John Deere assembled a real demo vehicle with the proposed powertrain and conducted some in-field testing, from which encouraging experimental results are observed.</p>

No description available.

No description available.

No description available.