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Research On The Energy Efficiency Of Electric City Bus During Regenerative Braking

Posted on:2012-07-19Degree:DoctorType:Dissertation
Country:ChinaCandidate:B ChouFull Text:PDF
GTID:1222330392452110Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
Regenerative braking is one of the key technologies to improve the energyefficiency of electric city bus. Concerning about the energy efficiency duringregenerative braking, this dissertation will focus on four research aspects: analysis ofkey factors that impact the potential of regenerative braking under typical city bus drivecycles, evaluation method and index for regenerative braking system, design ofregenerative braking strategy and simulation modeling of energy flow analysis duringregenerative braking. The above jobs will be contributed to the development andoptimization of regenerative braking system.The impact on the potential of regenerative braking, which mostly rests with busconfiguration parameters and drive cycle, is analyzed,an easy formula for brake anddrive energy calculation is acquired by data survey and multiple linear regressionanalysis. A method to assay the relationship between the braking energy ratio of driveenergy and vehicle configuration parameters is concluded. The distribution results ofbrake energy to velocity, deceleration and braking power under typical city bus drivecycle is counted.An evaluation method of regenerative braking system is founded based on brakeenergy flow model of electric city bus, which includes two indexes--the six-factorcontained regenerative braking system efficiency and regenerative braking contributionrate. Regenerative braking contribution rate, which takes vehicle parameters, drivecycle and regenerative braking system efficiency into account, is a comprehensive andscientific index to evaluate the effectiveness of regenerative braking system.A design fundamental of regenerative braking control strategy, which emphasizesthe consideration of brake safety, braking manipulation uniformity and optimizedregenerative braking system efficiency, is established. Several typical braking controlstrategies aiming at an electric city bus is designed according to China Typical City Bus(CTCB) Drive Cycle, merits and drawbacks are analyzed under above designfundamental. A modified regenerative braking control schedule--asynchronous parallelbraking strategy with rear axle brake pressure limited, is designed especially for electriccity bus under CTCB drive cycle, which can fulfill the above design fundamental while with simple design and low cost.A Matlab/simulink based simulation toolset, which could finish the analysis of theregenerative braking system efficiency and contribution rate during regenerativebraking under different vehicle parameters, drive cycles and braking control strategies,is developed. The analyzed results indicate that this toolset is an effective one for theresearch on regenerative braking.The research methods and results of this dissertation were helpful to thedevelopment and research of regenerative braking system of other electric vehicles.
Keywords/Search Tags:electric city bus, regenerative braking, drive cycle, energyefficiency, braking control strategy
PDF Full Text Request
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