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1	Evaluating the roll performance of a hydraulic-interconnected suspension system for an electric bus / Utvärdering av krängprestanda för ett hydrauliskt sammankopplat fjädringssystem för en elektrisk buss Ramachandran, Dinesh January 2021 (has links) Electric buses often have batteries installed on the roof structure to have a better space utilization. This increases the height of the centre of gravity of the vehicle, affecting its roll stability. The existing vehicle setup uses an anti-roll bar to provide the roll stiffness. However, increasing the roll stiffness of the anti-roll bar for providing the required roll stability of an electric bus is limited due to the increase in weight of the anti-roll bar, its material properties and the design constraints. An alternate for the air suspension system is identified through a literature study. The identified system, an interconnected hydro-pneumatic suspension, is modelled analytically and compared to the air spring system. Multi-body simulations are performed to understand the roll performance.\par The thesis work also estimates the system's energy efficiency, and the feasibility of packaging the system within the existing vehicle architecture is studied in CAD software. The roll gradient of the vehicle is shown to improve compared to the existing air-spring system. The study also find that implementation of hydraulic-interconnected system can result in reduction of the unsprung mass of the vehicle. / Elektriska bussar har ofta batterier installerade på takkonstruktionen för att få ett bättre utrymmesutnyttjande. Detta ökar fordonets tyngdpunktshöjd och påverkar dess krängstabilitet. Den befintliga fordonskonfigurationen använder en krängningshämmaren tillsammans med luftfjädrar för att ge den krängsstabilitet som krävs. Men att öka krängstyvheten hos krängningshämmaren för att ge den nödvändiga krängstabilitet hos en elektrisk buss är begränsad på grund av ökningen av vikten av krängningshämmaren, dess materialegenskaper och konstruktionsbegränsningar. Ett alternativ till luftfjädringssystemet identifieras genom en litteraturstudie. Det identifierade systemet, ett sammanlänkat hydro-pneumatiskt fjädringssystem, modelleras analytiskt och jämförs med luftfjädringssystemet. Multibody-simuleringar utförs för att förstå fordonets krängprestanda. par Avhandlingsarbetet uppskattar också systemets energieffektivitet och möjl-igheten att paketera systemet inom den befintliga fordonsarkitekturen studeras i CAD-programvara. Fordonets krängningsgradient har visat sig förbättras jämfört med det befintliga luftfjädringssystemet. I studien konstateras också att införandet av hydrauliskt sammankopplade system kan leda till en minskning av fordonets ofjädrade massa. Electric bus Centre of Gravity Roll gradient Hydro-pneumatic suspension Multi-body simulations Co-simulation Elektrisk buss Tyngdpunkt krängningsgradient Hydro-pneumatisk fjädring Flerkroppssimuleringar Co-simulering Vehicle Engineering Farkostteknik
2	En elektrifiering av den interna busstrafiken på Stockholm Arlanda Airport Zisimopoulos, Dimitrios January 2016 (has links) Functional and cost effective systems for the full electrification of a bus network are areas of intense research and development. The electrification can be accomplished using different technological solutions, for example using opportunity charging or using an electric road system – ERS. Both opportunity charging and ERS have the potential to be integrated into already existing bus lines. With opportunity charging, the regular dwell time at the end stops is used for the bus to recharge its batteries and with an ERS the bus can charge dynamically along the road. The purpose of this report is to analyze how the existing Alfa- and Beta line at Stockholm Arlanda Airport, in a functional and cost effective way, can be electrified using either opportunity charging or an ERS. The tradeoff between required charging power, battery capacity and the necessity to change the existing running schedule is explained in detail. In addition, the impact on the electrical grid is analyzed based on different load profiles of different charging stations using different power levels. The analysis is based on real data from the Alfa – and Beta line with its existing buses, the electrical grid at Arlanda and data provided by both the leading (electrical) bus manufacturers and the leading charging infrastructure manufacturers. The outcome of this report suggests that a full electrification of the existing Alfa- and Beta line has the potential to lower CO2-emissions and energy use at a functional and cost effective way. Electric bus electrical buses fast charging opportunity charging electric road systems ERS conductive inductive charging BEV electrical grid electrification TCO infrastructure charging infrastructure Arlanda airport Elektrisk buss elbuss snabbladdning hållplatsladdning elväg ERS laddstation konduktiv induktiv laddning BEV elnät elektrifiering TCO laddinfrastruktur elfordon fossilfri fordonsflotta Arlanda flygplats

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Evaluating the roll performance of a hydraulic-interconnected suspension system for an electric bus / Utvärdering av krängprestanda för ett hydrauliskt sammankopplat fjädringssystem för en elektrisk buss

En elektrifiering av den interna busstrafiken på Stockholm Arlanda Airport